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Sources: Burchard; biographical and autobiographical material
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Department members also took part in the organization, direction and work of war-related projects conducted in, or in association with, the Department of Metallurgy. Several of these were of large size and protracted duration. The histories of these projects, will be considered below.
- Nonmagnetic steels: J. Chipman, M. Cohen, A.R. Kaufmann
- High-temperature alloys: N.J. Grant
- Uranium supply: A.M. Gaudin, R. Schuhmann, Jr.
The MIT Metallurgical Project of the Manhattan Project:
- Production of massive uranium from powder: J. Wulff, J. Chipman
- Uranium metallurgy: J. Chipman, A.R. Kaufmann, M.Cohen,
- Beryllium metallurgy: A.R. Kaufmann, M. Cohen
- Crucibles for plutonium: J. Chipman, F.H. Norton
Burchard describes a project carried on in 1941 by Professor Chipman in collaboration with Professors Cohen and Kaufmann for the development of nonmagnetic steels that could be used for light armor near magnetic compasses. Burchard explains that "ordinary armor plate could not be used because of its effect upon the compass, yet the pilot. .. needed protection both on the bridge of a ship and in aircraft." The project, with the assistance of N.J. Grant and D.L. Guernsey among others, developed several suitable steels (Burchard, p. 183).
A new subject, corrosion and heat-resistant alloys, had been included in 1931-32 among the subjects available to students, as mentioned in Chapter 3. In the early 1940s, the growing interest in gas turbines, turbo-superchargers, and jet propulsion units created an urgent need for materials that could withstand the attacks of ever higher temperatures and more corrosive atmospheres. In addition to possessing the properties required for performance in service, the alloys had to lend themselves to being formed into the desired shapes. Nicholas J. Grant, as Burchard reports, for three and one-half years directed a program of development, testing, and treatment of suitable alloys. The program, which required the application and refinement of the art of casting, was carried out in the first independent precision casting laboratory in the country. This wartime project was the beginning of a program on high-temperature metals, which, under Professor Grant's direction, has continued to the present.
Manhattan Project
The contributions of MIT's Department of Metallurgy to the Manhattan Project consisted of new developments in mineral dressing, metallurgy and ceramics. The most important of these developments will be described in the following.
The development of atomic energy needed a large supply of uranium, but the available raw materials were of low grade and there was no experience in processing them. A uranium raw materials project was set up at MIT under Professor Gaudin as Director and Professor Schuhmann as Associate Director. Schuhmann, in an unpublished essay, has described how their research team attacked the technical problems and in particular how Gaudin, he, and their associates worked out a process suitable for uranium-bearing gold ore tailings. Since the process originally assigned to the laboratory for investigation was unpromising, the investigators had to learn to try other approaches in spite of restrictions on comrnunirations due to the compartmentalization imposed by the government in the interests of security. The team succeeded in devising new, innovative, and practical technology for recovering uranium from low-grade raw materials. By the middle of the 1950s the work was declassified and published (Schuhmann).
According to an account by Burchard, Professor Wulff applied powder metallurgy briquetting techniques to uranium and produced solid shapes of the metal which were shipped to the "Metallurgical Project" at the University of Chicago. In a related effort, Professor Chipman, in collaboration with R.J. Anicetti of Metal Hydrides, Inc., had worked on a similar problem and had derived a method for producing solid uranium castings from powder. Burchard writes that, with the assistance of researchers borrowed from the University of Chicago, "the method was perfected and the equipment enlarged to handle several hundred pounds of metal a day. The castings produced were for the now celebrated 'pile', which was built under the North Stands at Stagg Field in Chicago and produced atomic power for the first time on 2 December 1942" (Burchard, pp. 210-211).
The work on the consolidation of uranium was followed by a series of metallurgical investigations involving uranium and beryllium metal and an extensive ceramic investigation carried out at MIT. There is no clearer or more authentic way to report these investigations than by quoting Professor Chipman, the director of the MIT Metallurgical Project of the Manhattan Project. The following paragraphs are taken from his autobiography prepared in 1977 for the National Academy of Sciences.
My war work was mainly with the Chicago division of the Manhattan Project. It began at MIT with the development of vacuum furnaces for melting and casting the pyrophoric uranium powder produced by Metal Hydrides. Arthur Compton asked me to come to Chicago as Chief of the Metallurgy Section of the Metallurgical Laboratory. I had four very competent group leaders ... Also I maintained the contact with other metallurgical laboratories at Battelle Institute, National Bureau of Standards, Ames, Iowa and MIT. ... At MIT the work was in part a continuation of my earlier work. When Cyril Smith at Los Alamos complained that he could not buy sound beryllium rods, the MIT group under Morris Cohen and Al Kaufmann modified the uranium furnace to melt and cast the commercial product. This was then extruded by a method developed by Kaufmann of using a copper or soft iron jacket as a lubricant around the beryllium billet. The coating was then stripped off leaving a sound beryllium rod.
A principal problem at Chicago was the protection of fuel elements against corrosion by the cooling water of the Columbia River. After many trials of dipped or plated coatings it became evident that the uranium "slugs," about 8 inches long and 1 1/4 inches diameter, would have to be encased in a metal jacket. Aluminum was the obvious metal. John Howe's studies of corrosion had demonstrated that an aluminum cover and the aluminum tube were adequately resistant to Columbia River water. The aluminum "cans" were impact-extruded by Alcoa. We had to develop a method for canning the slug such that complete thermal contact existed at every point. This problem was solved by Al Greninger by dipping the slug into a molten zinc-base solder and inserting it, hot, into the can. The excess aluminum was trimmed oft the end crimped on an aluminum end piece and the closure completed by the then very new heliarc welding. The success of the Hanford reactors depended upon 100 percent perfection in the pieces. One failure could have meant catastrophe. Imperfection in the bond between slug and can could cause a hot spot with failure of not only the piece but the whole pile. The inspection method known as the frost test was developed by AI Kaufmann at MIT, perfected in Chicago and set up at Hanford. The pieces were immersed over dry ice in acetone. When brought out they frosted in the air. At any spot where the bond was imperfect the frost melted rapidly and any such piece was discarded. After the war was over and at the time the Smythe Report was written there had not been one failure in the Hanford reactors. In my opinion both Greninger and Kaufmann should have had the Medal of Merit; but then no one asked me.
With Hanford in operation my attention turned to helping Los Alamos. I have mentioned Kaufmann's perfection of beryllium. The next was production of crucibles for the vacuum-melting of plutonium and enriched uranium. Several ceramic laboratories declined to undertake it and I persuaded F.H. Norton at MIT to take it on. It was about this time also that I began spending most of my time at MIT with frequent visits to Los Alamos. For melting uranium we perfected a high-purity magnesia crucible and these were made in several sizes and considerable numbers. At the start it was thought that plutonium would have to be oxygen-free. Our experience with other metals indicated that a non-oxide crucible would be needed. Leo Brewer at Berkeley showed that the most stable sulfides were CeS and ThS and he made a number of small crucibles of each. We concentrated on CeS of larger sizes. Cerium sulfide was not available and, following Brewer, we converted Ce~2~O~3~, to CeS, by reaction with H,S; this was hydrogen-reduced to Ce,S, and the final step was further reduction with metallic cerium. The resulting brassy product was ground and shaped into crucibles which were fired in vacuo using a graphite susceptor at 17000 C. We had progressed up to about 4 inches high by 2 inches diameter when it was discovered that a little oxygen would do-no harm and thereafter plutonium was melted in our MgO crucibles.
Materials Policy and Materials Research Elsewhere at MIT
Materials problems were also being addressed in other parts of the Institute. On the level of policy, President Compton served on the Baruch Committee, which was concerned with the country's supply of rubber. Experimental work directed at the reclamation of rubber, especially neoprene and butadiene, was conducted by Professor Ernst A. Hauser of the Department of Chemical Engineering. Research projects in other departments involving materials problems were concerned with dielectrics and synthetic mica, fluoride crystals, the properties of roller bearings, and the flame hardening of steel.