TITANIUM: A NEW METAL FOR THE AEROSPACE AGE

Charles R. Simcoe

TITANIUM is familiar to many Americans in consumer items. It is available in jewelry, wristwatches, golf clubs, eyeglass frames, bicycle and auto engine parts, handguns, and even batteries for cameras. A growing application is in the biomedical field where it is used in prosthetic knee and hip joints. The most spectacular use may be for the architectural covering of the new Guggenheim Museum in Bilbao, Spain designed by Frank O. Gehry. These consumer uses were not anticipated in the late 1940s and the 1950s when titanium was seen as a future structural material for defense applications.

Titanium was discovered in 1790 by William Gregor an English clergyman and amateur chemist. It was rediscovered in 1795 by an Austrian chemist, Klaproth, when studying the mineral rutile. It was Kloproth who named this new metal titanium after the Titans, the giant sons of the earth.

Titanium is Element No. 22 in the Periodic Table. Its density is 4.5 grams/cubic centimeter, midway between aluminum at 2.7 and iron at 7.86. It has a melting point of 1812 C (3290F) compared with 1535 C (2785F) for iron. The low density and high melting point compared with iron indicate a metal with structural potential. When the great resistance to corrosion was discovered, this further enhanced the uses for which titanium could be unique. It seemed to be the ultimate answer for a strong, lightweight, corrosion-resistant metal for numerous structural designs.

These advantages looked promising in the late 1940s and early 1950s to a military on the cutting edge of developing jet engines, supersonic aircraft, missiles, and lighter-weight trucks, tanks, landing craft, and other hardware for the cold war and the Korean Conflict. The problem was the lack of an industry for producing titanium.

THE FIRST attempt to make titanium metal in the United States was at the General Electric Company Research Laboratories at Schenectady, New York. General Electric Company was looking for a light bulb filament to replace the cotton originally used by Thomas Edison. Tungsten was known to be the likely candidate but a process was not yet available to produce ductile tungsten. Titanium was believed to have a high melting point, which was a requirement for filaments. A young, graduate from New Zealand with an advanced education in Europe was on his way home in 1905 when he stopped in the United States and was hired by General Electric to explore the possibility of finding a process to produce titanium metal. His name was Dr. Mathew Hunter and while he did not solve the problem he had enough success to be counted as the first research engineer to produce a small quantity of not very pure metal. He at least determined that the melting point was about 1800-1850 C not the 6000 C previously thought. At this point General Electric lost interest and Hunter moved on to nearby Troy, NY to become a professor at Rensselaer Polytechnic Institute where he spent the rest of his career. He was considered the grand old man of titanium in later years when titanium became a common metal in the aerospace age.

Another earlier attempt to make titanium was in the 1920s at the Phillips Glow Works at Evindhoven, Netherlands. This process was the thermal dissociation of titanium iodide and the deposition of the titanium on a hot tungsten wire. Year’s later samples of this material would be studied at the United States Bureau of Mines and would arouse their interest in pursuing a more practical process for titanium production.

In May 1940 a middle aged research engineer immigrated to the United States from Luxembourg with a process and a patent for making titanium. He fled just ahead of the Germans who were conquering Europe. His name was Dr. William J. Kroll and his process would become the basis for the titanium industry for this country and overseas. It was not the first time that Kroll had been to the United States. He came here in 1932 in an attempt to sell American industry on the value of titanium. He failed to arouse interest in his process or in titanium. He was a researcher with the solution to a problem that no one had. Only laboratory quantities of titanium had ever been produced and the limited work performed on these samples had not lead to further effort, except for the intense interest by Kroll.

WILLIAM J. KROLL was born in 1889 at Esch, Luxembourg. His father was manager of a blast furnace plant and William and his five brothers were all educated as engineers. He attended a Jesuit high school founded in 1603 where he received an education in the classics and in chemistry and physics. He earned the Doctor of Engineering degree in the field of metallurgy from the Royal Institute of Technology at Charlottenburg, Germany in 1917.

After several years of employment in Germany, Austria, and Hungary, Kroll established his own research laboratory in a large home he purchased in his native Luxembourg. There he conducted research in metallurgy and in electrochemistry of importance to science and to industry. He worked as a lone experimenter with only a secretary and laboratory assistant as his staff. He never married so his work became his life. Out if his research were developments in alloys of aluminum, magnesium, copper, lead, and most important titanium. It seems that his initial interest in titanium was as a substitute for beryllium in the high-strength copper-beryllium alloy and came as early as 1928.

Kroll had some financial help for this research from the German firm of Siemens and Halske. When they lost interest in supporting the work, Kroll obtained control of the foreign patent rights and invested his own funds to continue development in his private laboratory. By 1938 he had produced 50 pounds of metal. He made a second trip to the United States to again generate interest in his work. He visited major American corporations; including General Electric Corporation, Westinghouse Electric Company, International Nickel Company, and Union Carbide Corporation. He also visited a former classmate from the Royal Institute of Technology an American named Samuel Hoyt who was a Metallurgical Manager at AO Smith Company. Again he failed to find an interest in his process or in titanium.

The first published report on Kroll’s process was a paper he presented at the 1940 meeting of the Electrochemical Society. That same year he was issued United States Patent # 2,205,854 for his invention. Kroll’s process was a modification of the sodium reduction of titanium tetrachloride used by Hunter. Kroll, however, used magnesium instead of sodium as the reducing agent. The resulting metallic product was a sponge-like collection of particles that had to be cleaned by acid leaching of residual magnesium and magnesium chloride contaminants. The sponge was then crushed to powder, compacted, and heated at a high temperature to sinter it into a solid mass. The resulting metal generally contained impurities, which affected the properties.

After Kroll became a resident of the United States, he worked until 1944 as a consultant at the research laboratory of Union Carbide and Carbon Corporation at Niagara Falls, New York. .

THE UNITED STATES BUREAU OF MINES (BOM), Metallurgy Division headed by Dr. Reginald Dean took an interest in titanium metal based on limited property measurements on laboratory material made at the Phillips Glow Works in Europe. The effort was initiated in 1938 but made little progress before the beginning of WWII. The Bureau of Mines began experimenting with Kroll’s process under the direction of Frank S. Wartman at the Salt Lake City Experimental Station during WWII. Early researchers included James R. Long, O. C. Ralston, and Frank Cservenyak. Titanium was made in 15-pound batches by 1944.

At this stage of development, Kroll became a consultant to the Bureau of Mines at Albany, Oregon. His process was being used to develop a new metal, zirconium, for use in atomic reactors. Zirconium is in the same group in the periodic table as titanium and would respond to Kroll’s process. Although zirconium is heavier than titanium, it has a low absorption rate for neutrons; thus, was selected for atomic reactors for the Navy Nuclear Submarine Program.

Kroll’s process and the support needed to carry on the research on titanium came together at a new BOM plant in Boulder City, Nevada. The only thing missing for Kroll was his patent. The Alien Property Custodian had confiscated it during the war. Kroll would have to fight through the courts to regain custody.

TITANIUM made its first steps beyond the Bureau of Mines in 1946 when a contract was awarded to Battelle Memorial Institute in Columbus, Ohio to study the properties, the welding, and the fabrication characteristics of titanium and its alloys. The Bureau of Mines supplied the titanium and the funds were supplied by the Air Force by way of the Douglas Aircraft Company.

Battelle Memorial Institute was founded in 1929 with an endowment from the will of Gordon Battelle. Later an additional endowment came from his mother. The Battelle family fortune was made in the iron and steel industry in southern Ohio. Gordon Battelle believed that the steel industry would benefit technically and economically from modern research. Battelle Memorial Institute is a contract research operation, that is, they performed research for industry and later government agencies on a fixed fee basis. Battelle supplied the research staff and the laboratory equipment and the contractor paid for their services. In this manner companies, associations, and the government who did not have the staff or laboratory facilities could contract for research studies.

Battelle Memorial Institute started with a small staff of experienced researchers under Horace Gillett from the Federal Bureau of Standards. It grew slowly in the first few years of the great depression. By the late 1930s and into the war years of the 1940s the staff had grown to several hundred personnel.

The research metallurgists who conducted the research on this first titanium project would become pioneers in the field. P. J. Maddex and S. A. Herres would join a major producer of titanium mill products. Bruce Gonser, Robert Jaffee, Howard Cross, and Connie Voldrich would remain at Battelle to work on titanium for the next 10 to 12 years. This latter group would continue at Battelle until retirement.

Every branch of the armed forces as well as all the government agencies with an interest in this new metal followed the research work at Battelle in progress reports. This would be the first independent study of broad scope to evaluate the practical capabilities of titanium. After a two-year study a final classified report was issued in 1948. A major conclusion was that titanium and titanium-based alloys had great potential engineering importance and further development should be diligently pursued. This report and other evidence from work at the BOM, the Wright Patterson Air Force Laboratories, and the Army Ordnance Department at Watertown Arsenal provided the foundation for promoting a new industry based on titanium.

The BOM needed financial help in 1947 to continue pilot plant production. It was supplied by a contract from the navy for $25,000. The product was evaluated at P. R. Mallory of Indianapolis, Indiana by pressing and sintering powder. One of the research engineers, L. S. Busch, and a manager, Frank F. Vanderburgh, at Mallory would make significant contributions later at a titanium supplier.

E. I. Du Pont de Nemours & Company was the first commercial organization to commit resources to producing titanium. In late 1948 du Pont offered titanium sponge for sale at $5 per pound from their production of 100 pounds per day. Du Pont was a large producer of titanium dioxide that is used in paint and many other products as a whitener. Thus it was natural for them to be the first commercial producer of titanium sponge made by Kroll’s process from titanium tetrachloride. The Remington Arms Division of du Pont did research on the metal made from this sponge and would later be a major partner in producing metal for the aerospace market.

The first major conference on titanium was held in Washington D. C. on December 16, 1948. It was organized by Nathanial Promisel of the Navy Bureau of Aeronautics and Julius Harwood of the Office of Naval Research, and was held at the National Academy of Sciences. An assembly of 200 attendees heard papers presented by authors from Battelle, Remington Arms Division of du pont, P. R. Mallory, and the navy Bureau of Aeronautics. This meeting, held in such august surroundings and promoting great enthusiasm for the need for titanium, is considered the launching of this new metal. An endeavor which would require a decade to accomplish, utilizing dozens of metallurgical engineers in industry, at universities, and other research laboratories and several hundred million dollars investment by the federal government and the industries who became involved in production.

Many factors came together at this time that influenced all levels of government to cooperate in this endeavor. All through WWII there were shortages of certain materials vital to the war effort. Metals such as tungsten, nickel, chromium, manganese, and others were controlled by the War Production Board and released on priority bases for only the most important applications. The initiation of Korean Hostilities in June 1950 provided additional incentive for developing a new metal with such promising properties and ready availability in the United States. It was believed at this time that we were self-sufficient in rutile, the major ore of titanium. The cold war was underway and our experience with supplying Berlin, which was besieged within the Soviet sphere of influence in Eastern Europe, with all its vital supplies by aircraft showed the need for lightweight equipment for airborne use.

The development of a new metal is a daunting task. It required 30 to 40 years to bring aluminum and stainless steel from their original inventions to full commercial practice. There are many pitfalls along the way. Uses are attempted as fads because of the publicity of a new material. Problems arise during early stages that were never anticipated, even catastrophic failures endangering lives and property. Many technical difficulties arise regarding fabrication, welding, corrosion, and inappropriate applications. And then there is the struggle to develop alloys. There are few applications for unalloyed metal. It generally lacks the strength for structural designs. Thus the search for alloy additions and the necessary heat treatment to develop the properties for the high strength needed in industry. Numerous alloys are usually needed to fill the various requirements.

. WHEN sample quantities of BOM material became available it was distributed to interested laboratories around the country. These laboratories included those of the Army, Navy, and Air Force, as well as some industrial companies, such as, National Lead Company, and Kennecott Copper Company. Studies on this material revealed properties of immediate interest, especially the corrosion resistance and strength. The metal gained numerous advocates both within the military and in industry. The early promoters could visualize the use of titanium in naval vessels, armor plate, tanks, trucks, landing craft, aircraft structures, and airborne equipment. It might replace both aluminum and steel in the design of many defense applications. Industrial uses would be based on the combination of lightweight, corrosion resistance and high strength.

The enthusiasm for titanium reached the highest levels of the Defense Department where funding was obtained for further research and development. One of the earliest studies in search of alloys of superior mechanical properties was the Rand Program of the Air Force, Air Material Command. This program financed a laboratory project at Battelle Memorial Institute. The objective of this project was to screen a wide variety of alloy additions for their affect on both the physical and mechanical behavior of titanium.

The first goal of the Battelle project was to design a furnace that could melt titanium powder or sponge in an atmosphere free of oxygen, nitrogen, and hydrogen. It was known that these gases which are present in air were harmful to titanium metal. This was accomplished by constructing a copper, water-cooled, crucible in which a vacuum could be maintained as the powder or sponge was fed into a very high temperature electric arc. In this manner numerous small melts were made containing various quantities of assorted alloy additions. The experimental examination of these small ingots revealed hardness, strength, and the physical affects of the alloy content upon the behavior of titanium when heated to high temperatures for hot working to shape or for heat treating to improve mechanical properties. The study of the affect of alloy additions to a base metal is of extreme importance in understanding the metallurgy of designing new alloys.

THIS FIELD OF SCIENCE is called “heterogeneous equilibrium ” and was developed in the late 19^th century by a yankee from Connecticut named Willard Gibbs. Gibbs developed the theory but it was not applied to metal alloys until a Dutch researcher, Roozeboom, developed the phase diagram for iron-carbon alloys, that is, steel. Phase diagrams are needed for understanding the behavior of metal alloys as are road maps for exploring a country. They show at any temperature what territory exits when an alloy is added to a base metal.

Some metals, such as iron and titanium, undergo a change in crystal form upon heating to a high temperature. This is called allotropic transformation. Above 882 C (1620F) titanium is body-centered-cubic. Upon cooling below that temperature the crystals rearrange into the hexagonal-close-packed structure. Alloy additions change the transformation from a single temperature to a range of temperatures so that there is an area in the diagram where the two crystal structures coexist. The exact temperature range where the phase boundaries exist is very important in processing and heat treating alloys. To gain such information in the goal of developing titanium alloys of high strength, the defense agencies funded the measurement of many phase diagrams.

This first program, funded by the Air Force Air Material Command, was performed by, Craighead, Simmons, and Eastwood.at Battelle. Eastwood was Supervisor of the Magnesium Foundry. Craighead and Simmons were research engineers in his group. Eastwood was from Wisconsin with his undergraduate and graduate studies at the University of Wisconsin. He was an assistant Professor at Michigan College of Mining and Technology and was a research metallurgist at Alcoa before joining Battelle. Craighead was educated at Penn State and had worked at Alcoa and Reynolds Aluminum. Simmons was from the University of Michigan with experience at Packard Motor Car Company. This group conducted a project covering a large number of alloy additions to titanium. Their published papers in the Transactions of the American Institute of Metallurgical Engineers in 1950 contained hardness, strength properties and phase diagram results.

At about the same time that the Air Force work was underway, Kennecott Copper Company contracted a program at the Armour Research Foundation (ARF) in Chicago. ARF had been formed in the late 1930s to perform research for industry similar to Battelle. ARF, however, was affiliated with the Illinois Institute of Technology in Chicago and did not conduct research in metallurgy until after WWII.

While this limited research activity was underway, several steel producers began to show interest in titanium. They were the stainless steel producers; Allegheny Ludlum Steel Corporation, Crucible Steel Company, Republic Steel Corporation, and a specialty steel producer, Sharon Steel Company. These companies were attracted to titanium for its interesting properties which they might exploit as a new business and also because titanium might become a serious competitor to their regular business, stainless steel. During 1949 and into 1950 these companies bought titanium sponge from du Pont and melted and fabricated it into bar and sheet product. The material was used primarily for testing by various defense laboratories, universities, and industrial firms.

National Lead (NL) came on stream in 1950 as a second producer of sponge. They were doing pilot plant work at Sayreville, NJ and Niagara Falls, NY. NL was the biggest producer of titanium dioxide for paint and other applications. They took over production of sponge under contract with the BOM at the Boulder, Nevada Experimental Station.

NINETEEN FIFTY was a year of major importance in forming the new titanium industry. A joint venture was formed between Allegheny Ludlum and National Lead to produce sponge, melt and cast the resulting metal into ingots, and supply metal products. This organization was called Titanium Metals Corporation of America (TMCA). TMCA established a New York City office and the first person employed was Tom Lippert. Lippert had been a writer and editor at the well known Iron Age Magazine. He became a spokesman for the titanium industry throughout his career as vice president sales and in public relations.

A second arrangement was made between the Remington Arms Division of DuPont and the Crucible Steel Company called Remcru. The following year a third combination was formed between P. R. Mallory Company and Sharon Steel Company called Mallory-Sharon Corporation. This latter group did not have a sponge facility but bought their sponge from du Pont.

Research activities accelerated in 1950 and 1951. The Army Ordnance Corps at Watertown Arsenal began a large program of in-house research under Dr. Leonard D. Jaffe, and a major program of contract research with outside firms. They funded alloy development at Allegheny Ludlum, a variety of programs at Battelle and ARF, and phase diagram studies under Professor John Nielson at New York University (NYU). Dr. Nielson was a graduate of Yale who had been teaching metallurgy to engineering students. He built and staffed a new research division at NYU to conduct work on titanium. One of his research engineers was another graduate of Yale, Dr. Harold Margolin. This group would contribute to phase diagrams, alloy development, and mechanical behavior of titanium alloys.

The Air Force at Wright Patterson Air Force Base, Dayton, Ohio began extensive in-house and contract programs at this same time. This work was placed at Battelle, ARF, and other laboratories. The Air Force concentrated much of their phase diagram work at ARF, where Dr Max Hansen, an internationally known expert in phase diagrams, was the new Manager of Metallurgy Research.

Dr. Hansen was a long-time friend of William Kroll. Kroll was the chief sponsor for Hansen when he obtained his doctorate at the University of Gottingen in 1923. Hansen studied under the famous Professor Gustav Tammann who was a pioneer in phase diagram research. In 1936 Hansen published a massive compilation of phase diagram studies that he collected from the worldwide, published literature.

Hansen’s major field of research was aluminum and the use of aluminum alloys in aircraft construction. He was spirited out of defeated Germany at the end of WWII by the British to avoid his capture by the Russians. He accepted a teaching position at the Illinois Institute of Technology (IIT) in Chicago in 1947 and transferred in 1949 to the responsibility of Manager of Metallurgy Research at ARF. Under his guidance two supervisors, Harold Kessler and Dr. Donald McPherson, and a group of young metallurgical engineers, many from IIT, began work on titanium phase diagrams and titanium alloy development. Among these researchers were Dr. William Rostocker, Dr. Frank Crossley, Raymond van Thyne, C. Robert Lillie and others who would join the work as the contracts expanded.

Donald McPherson was from Ohio State University where he got his doctorate under the well-known corrosion expert, Dr. Mars Fontana. He had worked in several industrial laboratories before joining ARF in 1951. He became Manager of Metallurgy at ARF following Hansen’s return to Germany in 1954.

Hal Kessler received his undergraduate degree in metallurgical engineering at Case School of Applied Sciences (now Case-Western Reserve) in 1943. After working at NACA (later NASA) for several years he went into the Army Air Corp and was assigned to Wright-Patterson Air Force Research Laboratory. In 1946 Kessler joined ARF and started his career in titanium on a project sponsored by Kennicott Copper Company. Later Kessler and his group worked on alloy development for both the Air Force and the Army Ordnance Corps.

As the phase diagram and alloy development studies funded by the various government agencies were getting underway in 1950 and 1951, a commercial research project on alloy development supported by Remcru was started at Battelle. This research would have profound implications in the future of titanium alloys. It was performed by Dr. Robert Jaffee and his staff of research engineers, which included Russell Ogden, Dan Maykuth, Frank Holden and Dean Williams, with the assistance of Dr. Walter Finlay of Remcru. Robert Jaffee was a native of Chicago and received his B.S. Degree in Metallurgy at the Armour Institute (now Illinois Institute of Technology). He received graduate degrees from Harvard University and the University of Maryland. He began his career as a research engineer at the University of California and worked at several other laboratories before joining Battelle in 1943.

Their program was an investigation of alloys of titanium and aluminum with the addition of a third element. None of the previous work at Battelle included alloy systems of titanium and aluminum, therefore, Jaffee and his group were free to perform this study without conflict with the government supported research at Battelle. Many alloy compositions were examined and patents applied for in a broad range of alloys. The most important of these alloys were ones containing titanium with aluminum and vanadium. Later an alloy in this group would become the most important one in aerospace applications.

The widespread research activity in the early 1950s is shown by the extent of the contracts with universities and industry. Universities included Brown (corrosion), Carnegie Institute of Technology (mechanical properties), Case School of Applied Science (mechanical properties), Columbia (phase transformations), MIT (machining), Michigan (machining and heat treatment), RPI (welding), Syracuse (impurities), and Cal Tech (phase studies). Major industrial firms were Allegheny Ludlum (alloy development), Driver-Harris (wire drawing), Fansteel Metallurgical (coatings), A. O. Smith (welding), Sam Tour (chemical analysis), Worchester Pressed Steel (sheet forming), and dozens of firms with smaller activities.

THE PRODUCTION of titanium sponge and titanium metal products was slow in getting started. The year 1951 when the Material Advisory Board (MAB) of the National Research Council, National Academy of Sciences was forecasting the need for 30,000 tons of metal products, the total shipment was only 75 tons with 500 tons of sponge produced. This was barely enough metal to supply the research contracts and provide some metal to the aircraft industry for evaluation. At the same time Col. John Dick of the Air Force was urging the aircraft manufacturing companies to use titanium as a replacement for steel. Col. Benjamin Mesick of the Army Ordnance Corp placed an order for $1,000,000 worth of metal to help the industry get underway. The problem was not just a lack of orders but the difficulties encountered in melting sponge and fabricating products with this new and unfamiliar material. It was common belief that titanium could be melted, rolled and shaped on the same equipment used for stainless steel. To some extent this was true but the metal was much more difficult to handle than was stainless. As orders came in the steel mills found that they produced more scrap than useful metal.

Even more important for the eventual future of titanium as a structural material was the pricing in 1951 of the ordered product: $15 per pound for sheet, $12 for plate, and $6 for bar. Perhaps the promoters within the armed forces and the other government agencies thought that this was a starting price that would decrease drastically once the increased production levels were reached. At this time even the end users within the aerospace industry did not lose their enthusiasm for titanium.

Shipments for 1952 increased only to 250 tons of metal, with production of sponge at 1075 tons. This wonder metal was getting off to a very slow start. The pressure to increase production started at the beginning or the sponge end of the process. The thinking seems to have been that if sponge were made in quantity the metal production would follow. In any case the whole industry was based on sponge so increased production had to start there.

The government provided support for this increase in sponge production by funding projects for construction of new or expanded facilities. The Office of Defense Mobilization (ODM) funded the construction and the General Services Administration (GSA) agreed to buy any surplus product for the national stockpile of strategic materials. Numerous industrial companies responded to this program. The first contracts went to the companies already in the business, TMCA (3600 ton/year) and du Pont (2700 ton/year). Later, contracts were made with the Crane Corporation (6000 ton/year), Dow Chemical (1800 ton/year), and Union Carbide Corporation (7500 ton/year). This new production was planned to meet the goal of 22,000 ton/year forecast to fill the needs of the aircraft and jet engine producers. One additional company, National Distillers and Chemical Corporation, entered sponge production (7500 ton/year) later with their own funds.

THE DEMAND for titanium metal products increased in 1953 under the urging of the Air Force. The aircraft companies were beginning to use titanium in the new fighter and bomber aircraft and Pratt and Whitney was designing it into the latest engines. The producers, however, were on a difficult learning curve. They could not keep up with the demand. The total production of metal products was only 1100 tons. This was unacceptable to a defense department trying to maintain support for the troops in Korea and to build what was required for the cold war with the Soviet Union. The Air Force held a meeting in the spring of 1953 to discuss the critical situation with all the parties involved. There were representatives from twelve airframe companies, five jet engine companies, and nine government agencies looking for answers from the titanium producers. The result was the realization by all that they could not fulfill every requirement and priorities had to be established.

Later in the year a senate subcommittee under Senator George Malone was formed to investigate the titanium problems. Many witnesses were called before this committee to evaluate the problems and to determine the true value of titanium to the defense effort. Again the Air Force, the airframe, and the jet engine representatives were enthusiastic about the need for this new metal. The most vocal witnesses were the high level executives from Lockheed, North American, Douglas, Boeing and other aircraft companies. They were predicting plane designs in the near future that would need 40% to 60% of the aircraft weight in titanium. One individual stated that his firm would need 250,000 tons annually in five years. Another put their needs at 800,000 tons by 1960 if the country were again mobilized for war. Added to these predictions were others from the jet engine manufacturers and the Army Ordnance Corp that would raise the needs to levels equal to the production of stainless steel.

A voice of caution came from the Office of Defense Mobilization (ODM) that argued that the forecast would require 50% of the total Air Force budget. A lone dissenter from the titanium industry was Dr. Edwin Gee of du Pont who thought that more effort should be spent on finding less expensive processes for making the metal. He reasoned that the cost of titanium as produced would prohibit the general use as envisioned by the end users. The titanium promoters, however, won the day and new goals for production were established by ODM at 37,500 tons/year of titanium sponge.

A MUCH MORE SERIOUS TECHNICAL PROBLEM appeared in early 1954 while attention was focused on the future needs and the supply problems. Pratt and Whitney Engine Division and Douglas Aircraft received shipments of metal that was brittle. Sheet metal would tear and engine parts would crack under very low stresses. The problem was quickly traced to high hydrogen contents in the metal. Since a minimum hydrogen level had never been specified and all the metal at the user’s plants and in the distribution pipeline could be contaminated, work on titanium came to a standstill. A massive effort was launched immediately to determine the source of the hydrogen, the safe level for specification, new methods for hydrogen analyses, embrittlement mechanisms, and how to salvage all the metal on hand. Remarkable progress was made by the cooperation of the producers, the users, the Air Force, the Army Ordnance, and the research laboratories and universities involved with titanium.

Vacuum annealing was quickly identified as a process for removing hydrogen from the contaminated metal, and the initial panic gradually subsided. The hydrogen problem, however, did not disappear. New levels of tolerance were established that required added vacuum processing for titanium.

Melting under vacuum to eliminate gases had been used for titanium in the earliest research at Battelle. Hal Kessler at ARF developed an improved process where he used compacted titanium sponge as an electrode in an arc melting technique. This process is called consumable electrode, vacuum, arc melting. The original idea was invented at Climax Molybdenum Corporation for use with molybdenum. Kessler adapted it to use titanium sponge. S. A. Herres who had moved from Battelle to TMCA scaled up the laboratory concept to production size and this process became standard melting practice after the hydrogen problem. Double melting and even triple melting is common in titanium for critical applications. Consumable electrode, vacuum, arc melting gradually expanded to other metals, especially nickel-based alloys and iron-based alloys for use in jet engines and other critical aerospace applications.

Attention turned to other difficulties affecting the use and production of titanium. The producers were making progress on improvements in the manufacture and quality of their product, but there was still a requirement for stronger alloys. One aircraft company had complained that they would not design titanium into new planes unless stronger alloys were available. Much of the titanium used up to this time had been lower strength commercially pure titanium (CP titanium). It was easy to process and the early applications were substitutions for other metals where heat resistance was more important than high strength. Each producer had developed alloys of higher strength, but these alloys were only moderately strong and more difficult to fabricate into parts. Fortunately for the industry an alloy was under development that would solve the problem.

The Armour Research Foundation, Metals Division, under the direction of Max Hansen had been working on a Watertown Arsenal contract for alloy development. Hal Kessler and his group of research engineers were studying various alloy systems, including those containing aluminum and vanadium. One if their most promising alloys contained six percent aluminum and four percent vanadium (Ti-6Al-4V). Sample ingots of this alloy were supplied to the arsenal for heat treatment, mechanical property, and ballistic studies. The Air Force initiated a contract at ARF to study the high temperature properties of interest to jet engine application. Later, ARF supplied 100 pound ingots of Ti-6Al-4V to the jet engine builders for evaluation. The success of this effort soon brought the alloy to the attention of the entire titanium world. The titanium producers immediately began production of the alloy, and in a short time it was designed into jet engines.

Since the ARF work was done under a Watertown Arsenal contract, the patent was the property of the arsenal. The arsenal delayed their patent application because they decided to keep their ballistic information secret. In agreement with Watertown Arsenal, ARF applied for a broad patent on Ti-Al-V alloys including the 6Al-4V composition. On the bases of a government-sponsored project resulting in the ARF patent application, one defense contractor ceased paying royalties to Remcru. This precipitated a lawsuit involving Remcru against the government and several users and producers. The lawsuit was eventually withdrawn leaving the invention of Ti-6Al-4V unsettled. To complicate matters a patent was granted to Watertown Arsenal on Heat Treating Ti-6Al-4V alloy. Now the arsenal, ARF, and Remcru could all claim to have invented the alloy. The final word seems to be contained in a letter from Charles F. Hickey, Chief, Technology Management Branch of Watertown Arsenal to Harold Kessler stating that he (Harold Kessler) was indeed the inventor of the most important alloy in titanium.

The importance of Ti-6Al-4V cannot be overstated. There probably would not have been a titanium industry without this alloy. An alloy becomes successful when it offers a combination of properties and characteristics that satisfy a wide variety of applications. An alloy does not have to be superior in all properties: a proper balance is more universally valuable. Ti-6Al-4V was the first titanium alloy to perform this role and with continued use it became a material that industry felt confident in using. As late as 2000, Ti-6Al-4V represented 75% of all titanium alloys produced. It was the most important alloy abroad, also. Japan, China, England and Russia produced it. It was used in the construction of the Russian Alfa Class Submarines.

MANY OF THE EARLY CONTRACTS FOR RESEARCH on all aspects of titanium science and technology were being completed in 1953 to 1955. Numerous technical papers were being published in a wide variety of journals each dedicated to a particular specialty, such as, welding, corrosion, phase diagrams and alloy properties. In addition the metal producers and their customers were developing processes and procedures for their own particular needs. All of this valuable information for the general use of titanium needed to be accumulated, analyzed, and repackaged into documents that could be used by other researchers or by designers and personnel on the shop floor. A $1,000,000 annual contract to perform this effort was awarded by the Defense Department to Battelle Memorial Institute in late 1954. The result was production over a 2½-year span of 80 technical reports and over 100 technical memoranda to a distribution list of 1800. The Battelle project, called the Titanium Metallurgical Laboratory (TML), was so successful that the Defense Department extended the contract to included other critical metals under development and the name was changed later to the Defense Metals Information Center (DMIC).

The problems in processing titanium in the producer mills, including hydrogen embrittlement, limited production of metal in 1954 to 1300 tons, barely more than in 1953. Sponge production, however, more than doubled to 5400 tons. Metal shipped in 1955 increased to 1900 tons and sponge to 7400 tons. The biggest use for the metal was in jet engines, and the biggest customer was Pratt and Whitney. Gradually the Ti-6Al-4V alloy was becoming the most important titanium product for the jet engine market.

Sponge production was moving ahead much faster than metal production. In addition, in a case of one hand not knowing what the other is doing, the government had contracted with the Japanese to exchange surplus grains and other foods for titanium sponge. This Japanese sponge which started as a trickle in 1953 reached 600 tons in 1955 and 3600 tons in 1957. The competition forced the price of sponge from $5 a pound in 1953 to $2.25 in 1957.

THE YEAR 1956 was the year that titanium began to show the promise that many promoters had hoped for this new metal. Metal production reached 5200 tons and sponge production nearly 15,000 tons. This performance yielded profits and attracted new investments and competition into the market. TMCA bought an old steel mill in Toronto, Ohio and added new specialized equipment for processing titanium. Republic Steel announced a $7 million expansion plus buying a 50% interest in the Crane Company sponge plant now called Cramet. National Distillers began producing sponge (5,000 ton/year) without government support. Mallory-Sharon added new plant equipment and other facilities. Two other companies with long-time interest in titanium, Allied Chemical Company and Kennicott Copper Company, announced they would jointly build a plant to make sponge and melt ingots. Two companies on the West Coast announced that they would begin melting sponge to produce ingots. They were Oregon Metallurgical Company in Albany, Oregon and Harvey Machine Company in Torrence, California.

While the business side of titanium was improving, most of the alloy product was going into jet engines. The airframe manufacturers were still grappling with problems in sheet material. They needed better alloys for forming parts and for improved strength. They, also, need more uniform properties. The variation in properties from one producer to another or even within a shipment from the same producer was a cause for concern. The learning curve for sheet products of titanium was more difficult than expected. The Department of Defense initiated a substantial project of $3,500,000 in 1956 to combat a host of sheet metal problems.

THIS PROJECT CALLED THE DOD SHEET ROLLING PROGRAM was administered by the MATERIALS ADVISORY BOARD OF THE NATIONAL RESEARCH COUNCIL( MAB). Representatives from all the major airframe manufacturers, the jet engine builders, the titanium producers, the armed forces, and other government agencies with an interest in titanium assembled at the headquarters of the Material Advisory Board at du Pont Circle in Washington D.C. One of the most comprehensive technical programs ever undertaken in metallurgy was designed by this group to overcome the problems hindering the rapid growth of titanium in airframe construction. Three promising alloys, including Ti-6Al-4V, were selected for study. Each of the three major titanium producers received orders for the three alloys. This material was distributed to the participating airframe companies and to other laboratories for testing and evaluating. A system of test procedures was designed so that everyone involved tested material from the same source and even from the same sheet. In this manner discrepancies were uncovered in laboratory technique of each participant as well as the variation in product. Periodic meetings were held at MAB of all representatives to report findings and to guide the program. Over several years this project produced not only improved alloys and improved material quality but also a much better appreciation of the reliability of titanium as an aerospace material. An indirect benefit was the close relationships resulting from the individuals of all parts of the industry participating in the common goal. This effort could only have been accomplished by using the office of a government agency, in this case the MAB, to bring all the interests together without regulatory consequences.

The improved business conditions and the resulting enthusiasm within the industry continued into 1957. First quarter metal shipments were 2200 tons, which indicated an annual goal of perhaps 9000 to 10000 tons. Titanium was on its way to becoming the aerospace metal that its promoters had hoped for. Then an earthquake shook both the aerospace industry and titanium. The Secretary of Defense, Charles Wilson, formerly of General Motors Corporation, announced a decision to base the defense of the country on missiles rather than on manned aircraft. The accompanying reductions and cancellations of contracts rocked the industry. The B-52s were cut from 17 wings to 11, and the contracts for the new Century Type fighters were either cancelled or extended over much longer times. The reduction in aircraft and engine production meant a near total collapse of the titanium market. This most promising of metals for the postwar era, which had received an estimated $200,000,000 in government support, was in serious danger of extinction by the very Department of Defense that had brought it into being.

THE RAMIFICATIONS were swift and drastic. Orders were cancelled and by the 4^th quarter of 1957 shipments skidded to 350 tons. The price of sponge plunged to $2.25 per pound as production mounted to 17,000 tons and the competition of 3500 tons of Japanese imports. Metal product prices decreased to average of $10 per pound. These prices continued to decline over the next several years to as low as $1.60 for sponge and $7.00 for metal.

The faint-of-heart were lining up to bail out of the industry. The Remington Arms Division of du Pont sold its 50% interest in Remcru to partner Crucible Steel Company. Crucible remained in metal production for a brief time then left the field. Cramet, jointly owned by Crane and Republic Steel ceased operation, and Republic stopped production of titanium metal products. Dow Chemical put their sponge plant on standby and shortly closed it. Union Carbide reduced production of sponge to 25% of capacity and later closed. Mallory-Sharon sold a 1/3 interest to the new sponge producer, National Distillers. Within a few years both P. R. Mallory and Sharon Steel sold their interest to National Distillers, and a new name of Reactive Metals was given the former operation. In 1964 U. S. Steel Corp. purchased a 50% interest in Reactive Metals. Even du Pont, the first company to enter production of sponge, closed their plant in 1962. Witnesses to this situation believed that the DOD Sheet Rolling Program was a major factor in holding together what remained of the industry.

It was in this low state of the business that a celebration was organized to honor the founders on the 10^th anniversary of the industry. The individuals chosen as founders were those “whose vision, perseverance and effort made possible the birth of the titanium metals industry”. For the most part the founders were involved in the very early years and many individuals who made significant contributions as the industry was getting underway in the 1950s were not included. The total list was 104 founders. The breakdown of those selected shows 29% were from the armed forces, 25% from the titanium producers, 14% from Battelle, ARF, and NYU, 5% from the pioneering staff of the Bureau of Mines, 9% from the various government agencies and 11% from the aircraft and jet engine producers. The remaining individuals were from a variety of organizations that did not fall into the above categories.

The changes in the titanium industry extended to many of the individuals selected as founders. Dr. William Kroll would return to Europe to make a home in retirement in Brussels, Belgium. Dr. Max Hansen left ARF in 1954 to accept a high level post in the metals industry in Germany. (In 1958 Hansen and Dr. Kurt Anderko, another German who worked with Hansen at ARF and who had returned to Germany with him, published a monumental second edition of the Constitution of Binary Alloys.). Two principal military supporters of titanium Col. Ben Mesick of Watertown Arsenal and Col. John Dick of the Air Force went on to other careers. Mesick moved to the University of Arizona and Dick joined Allegheny Ludlum. Nat Promisel of the navy became head of the MAB. There was a great fall-out of personnel from the many companies who left titanium. A few relocated with the remaining producers, but these companies were downsizing their technical staffs to only 40% to 50% of their former size. Even the major consumer of titanium, Pratt & Whitney, lost Win Sharp and Rudy Thielemann leaving Eli Bradley to promote the use of titanium in jet engines for the next 20 years until his retirement. Similar personnel losses were experienced in the airframe industry.

By the late 1950s and early 1960s the major research and development support for titanium by the government had ceased. The selected founders as well as the younger researchers were forced to find other areas of research or move on to other employment. Most of the personnel at Battelle remained there to perform other research. Battelle had a more experience staff that was better able to find other contract research. ARF on the other hand gradually lost all of their titanium research staff who moved on to universities and industry. NYU eventually left the metallurgical field of engineering and most of the staff moved to Brooklyn Polytechnic Institute. While many of these individuals continued to participate for a number of years in seminars and other technical meetings to provide their accumulated experience, they no longer were active in titanium research.

Titanium metal shipments would not exceed those of 1957 (5600 tons) until 1962 (6500 tons). During this time the remaining producers were pressed to find other applications for the metal. The reduced jet engine market was still the major customer, but slowly applications were found in chemical and nuclear plant construction where corrosion resistance was the primary property. The growing field of missile technology began to consume increasing although limited amounts of titanium. The civilian airline industry began using increasing amounts of titanium with the introduction of the new jet powered aircraft. These planes included the Boeing 707 and the Douglas DC-8. Later models were the Boeing 727 and 737, and the DC-9. All of these planes used a few percent of the airframe weight in titanium as well as the substantial weight in the engines.

One significant development in the 1960s was the building of the SR-71 military reconnaissance plane with a speed capability of Mach 3. This was an all titanium aircraft manufactured with Ti-6Al-4V and a new alloy Ti-13V-11 Cr-3Al. This latter alloy was a beta alloy that could be formed in the soft water-quenched condition and then age hardened to exceptionally high strength. Another early 1960s attraction was the interest in a supersonic transport plane. It would have been an all-titanium aircraft and was planned to compete with the European-made Concorde. It was planned to fly at nearly Mach 3 and would have used 200 tons of titanium per plane for a planned 200-plane fleet. The program was cancelled by congress in 1971.

THE JET ENGINE BUILDERS were the major consumers of titanium and Pratt & Whitney was the leader. Until the post war period Pratt produced only piston engines for aircraft. The transition to gas turbines after WWII was much more difficult for Pratt than for General Electric or Westinghouse who were long time manufactures of steam turbines. It was a complete reengineering for Pratt to transfer from reciprocation engines to rotating turbines. They made the transition successfully; whereas, Westinghouse Electric Corporation and Curtiss Wright Corporation, the other major piston-engine manufacturer, dropped out of the field.

Pratt & Whitney were the first to embrace titanium in their military jets in the early 1950s. Later when commercial jet engines became popular in the 1960s and beyond, they continued to expand the use of titanium. At one point in the early stage of commercial jets, Rolls Royce had developed a light-weight composite using carbon fibers for competition with titanium in the compressor stage of the engines. Both Rolls Royce and General Electric Company were planning to make this composite the material of choice in their engines. However, as told by Eli Bradley of Pratt & Whitney, the test engines failed the “chicken test”. The composite shattered when dead chickens were thrown into an operating engine. This was the test to see the reaction to ingested birds, and the failure doomed the use of the composite substitute for titanium.

Eli Bradley was the Chief Materials Engineer at Pratt during the crucial period of the development of the commercial jet engines. For twenty years he was a leading expert in titanium applications in the jet engine industry. Bradley was raised in Connecticut and graduated from Yale in Metallurgical Engineering in 1939. He joined Pratt & Whitney out of college and worked there his entire career. Eli Bradley received the ASM Engineering Achievement Award in 1975, and he was given the highest honor in metallurgy, the ASM Gold Medal, in 2002, the same award that was given to William Kroll in 1965.

THE INTRODUCTION of the wide-bodied air transport planes in the late 1960s improved the markets for titanium. Each Boeing 747, for example, consumed 15 tons of titanium products for the airframe and approximately 25 tons for the engines for a total of 40 tons. After a decline in shipments in the early 1970s, business increased with the construction of newer fighter planes along with improving markets in the chemical and nuclear industries. The new Grumman F-14 used 35% of the airframe weight in titanium and the McDonnell F-15 used 24%. Shipments improved by 1980 to an all time high of 27,000 tons. A number of factors coincided to produce the use of titanium to nearly the 30,000 tons forecast in the early 1950s. Civilian transport aircraft construction and chemical and nuclear uses reached peak levels and even export business had developed to serve a growing military and civilian aircraft production in Europe. This peak usage would not be repeated for many years because of the rapid decline in all of these markets in 1982-83. Not a single nuclear plant was sold in this country after the Three Mile Island problem in 1978. Chemical plant construction went into a long decline and aircraft sales leveled off during the recession in the early 1980s. The one bright spot was the B-1 bomber built by North American Rockwell. Each of the 100 planes built required 100 tons of titanium.

THE MOST RECENT COMMERCIAL AIRCRAFT DESIGNS use substantial amounts of titanium according to Rodney R. Boyer. Boyer has been an expert in the use of titanium in commercial aircraft since he joined Boeing in 1967. He is a Technical Fellow, at Boeing Materials Technology of the Commercial Airplane Group. The Boeing 777 uses 13,000 pounds of Ti-10V-2FE-3Al in the landing gear. This is a beta alloy that is heat-treated to 160,000 to 170,000 pound/square inch. Other alloys used in a variety of applications for this plane include commercially pure titanium, Ti- 3Al-2 ½ Sn, Ti-6Al-4V, Ti-6AL-2SN-4ZR-2MO-2SI, and a beta alloy Ti-3Al-8V-6Cr-4Mo-4Zr. This latter alloy according to Boyer can be heat-treated to 200,000 psi. In addition to the uses in the airframe, the Boeing 777 has approximately 25,000 pounds of titanium alloy in the engines.

The Air Force F-22 uses approximately 42 % (9,000 pounds) of titanium alloys in the airframe, although several alloys are now available the largest amount is still Ti-6Al-4V. The Pratt & Whitney engines for this plane, the F119-PW-100, contain Ti-6Al-4V and the newer alloy Ti-6Al-2Sn-4Zr-2Mo-0.2Si.

A FEW OF THE ORIGINAL TITANIUM FOUNDERS, who attended the 1960 celebration of the 10^th anniversary, formed a small committee in the late 1980s to discuss writing about their experiences in the development of the industry. They included Nate Promisel of the Navy and the MAB, William Harris of the MAB and Battelle, Robert Jaffee of Battelle, Hal Kessler of ARF,TiMet, RMI, and other producers, Robert Nycum of TiMet, Ward Minkler of TiMet, and Andrew Eshman of RMI. This group met over several years when they were attending other major metallurgical meetings. Their goal was to combine their experiences along with other information they would include into a book on the complete history of the development of titanium. It was an ambitious undertaking. A brief outline was prepared and one or two individuals wrote their sections, but others held back until arrangements were made for a firm commitment for financial support by the titanium industry. This help never materialized so most of the history was not written. Hal Kessler, who was Chairman of this group, has collected over a 40-year career a personal library of information on titanium. It was from among his papers that I obtained copies of the few documents that were written either for the 10^th anniversary celebration or for the intended history.

Among these writings was an article by an unidentified author for the 10^th anniversary called Titanium: Part Product, Part Cause. Another important article for the history committee was prepared by Andrew Eshman –Titanium The First Four Decades. A third document was a subcommittee report to the Manufacturing Chemists’ Association, Inc called A History of Titanium Sponge Manufacture written by E. R. Rowley and W. P. Cloyes. Finally there was Kessler’s write-up on his experiences in research, technology, and customer relations. These documents used in the preparation of the present history of titanium were augmented by a recent publication of The Minerals, Metals & Materials Society entitled The Emergence of the Titanium Industry and the Development of the Ti-6AL-4V Alloy by Stanley Abkowitz. Abkowity had worked at the Watertown Arsenal during the early 1950s and later at Mallory Sharon.

FATE HAS NOT BEEN KIND to the United States metals industry. In the past two decades, overseas competition, the movement of many industries off shore, and in some cases inadequate management have taken a toll. Some of the early supporters of titanium have disappeared from the industrial scene. Several are smaller employee-owned companies and others still operate but are no longer involved in titanium.

The titanium industry went through another shake-up in the 1990s. National Lead the 50% owner of TiMet (formerly TMCA) was acquired by a private interest group. Later Allegheny Ludlum Corp. sold their 50% interest in TiMet, and after a merger with Teledyne-Allvac Corp they purchased the Oregon Metallurgical Corp., the third major titanium producer. TiMet is the sole remaining producer of titanium sponge in the United States. All other requirements are satisfied by imports, mainly from Japan and Russia. Titanium mill products also are being imported from Russia for aerospace applications.

Numerous companies specialized in various operations to produce parts for the aerospace market: sheet metal fabricators, wire and rod drawers, tube manufactures, fastener producers, castings and powder metallurgy producers, and others. Two of these companies are at the forefront in making titanium forgings for engines, airframes, missiles, and other uses. They are the Wyman-Gordon Corp. in Millford, MA. and Ladish Forge in Cudahy, WI. Both firms have made parts since the first use in jet engines.

THE ORIGINAL enthusiast; individuals, companies, government agencies, universities, and research laboratories believed in a great future for a strong, lightweight, corrosion resistant metal. Their dream came to pass after a decade of difficult research and development and an investment of several hundred million dollars by the government and by industry. The cost of producing titanium, however, has limited its major applications to jet engine and airframe construction and some chemical corrosion uses. For these uses, however, titanium alloys are indispensable. The modern fan bypass jet engine would not be possible without titanium. Recently new markets have appeared in architectural construction, golf clubs and other consumer uses. However, it required 50 years for production to reach 30,000 tons per year, a goal forecast for 1960 by the early studies.

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