annual review
E. M. SHERWOOD
Less Common Metals flew technology and applications of bevllium, chromium, molybdenum, niobium, rhenium, tantalum, tungsten, zirconium, and titanium are reported and evaluated
or several years, this annual review has called atten-
Ftion to the possibility for use of space-age metals technology by the chemical process industry. Now, the new
knowledge of how to handle the less common metals has been widely disseminated, and some chemical industrial organizations have developed capability for processing these metals and their alloys. Further, whole new families of commercial and experimental alloys with well defined characteristics have been developed. Dispersion strengthening in several alloy systems has yielded materials with improved high temperature performance under load. I n this review, selected information sources are indicated which deal with the technology and applications of beryllium, chromium, hafnium, molybdenum, niobium, rhenium, tantalum, titanium, tungsten, zirconium, and their alloys. The reader will note that this list includes titanium, which is not the subject of a separate review article this year. Owing to limitations of space, coverage of individual metals will be restricted to separate tabular summaries (Table 11) of information by category (Table I) as presented in the source material in the bibliography. Evidence reflecting improved production know-how is to be found in the large number of publications describing less common metals in the form of forgings, extrusions, rolled shapes, sheets, and thin foils. Some increase is indicated in the use of vacuum technique in extraction and refining; of chemical vapor deposition in refining; and of energy beams in heating, melting, working, metal removal, and joining. Advances were made in chemical milling, in electrochemical and electrodischarge 78
INDUSTRIAL A N D E N G I N E E R I N G CHEMISTRY
machining, and in molecular forming. Solid-state bonding, ultrasonic, and cold-welding methods were used successfully in a number of applications requiring minimum modification of initial material characteristics, Almost 50y0 of the year’s related published material pertained to property data. Constitution and structure of new alloy systems were of major concern. An appreciable fraction of the physical property data dealt with superconductivity. Coatings for protection against high temperature oxidation continued to hold the attention of many investigators. Much is now known about why such coatings fail (“pest” reactions for example), but less is known about how to prevent failure. Many new applications for the less common metals were discussed. Important materials developments included the following : Beryllium-aluminum alloys in the composition range near 60Be-40Al Dispersion-strengthened chromium-base alloys Hafnium alloy systems with other less common metals Dispersion-strengthened molybdenum and demonstrated versatility of molybdenum as an alloying element in other less common metal systems Diverse new niobium alloys and intermetallic compounds (particularly those exhibiting superconductivity) and vapor forming of Kb$n strip for commercial use in superconducting magnets hTew rhenium alloy systems New titanium alloys, a broad range of new Ti-alloy data, and a general increase of interest in titanium as structural material Delineation of new superconducting tungsten alloys and vapor forming of tungsten shapes Dispersion-strengthened Zr alloys, new superconducting alloys containing Zr, and use of Zr as a minor constituent in other alloy systems A large body of information covering the less common metals in groups of three or more, usually those described as “refractory,” was added to the technical literature in the interval covered by this review. Articles reviewed progress on government-sponsored programs aimed at developing primary and secondary fabrication techniques for evaluation of new alloys and provided design data on these materials in sheet and foil form, with less emphasis
on shapes (8, 9, 46). Production techniques (33) and physical metallurgy (67) were outlined. The current status of the four metals Mo, Nb, Ta, and W and their alloys was assessed for structural applications (16, 43). Current practice in fabrication and coating technology was described. I n the area of refining, discussions included the production of electrolytic powders (30) and vacuum purification (57, 69). Progress in powder metallurgy yielded compacts with improved structural properties (15). An excellent review article appeared on the use of energy beams in metallurgy (42). New vacuum melting equipment was described (24, 64),and the quality of the materials so melted was characterized. Russian investigators (39) produced submicron-size particles of refractory less common metals by atomization of wires in an Ar plasma. The capability of such a process for producing hollow particles also was mentioned. Working of shapes (13, 31, 35) and forming of sheet (70, 13) by routine production methods gave excellent results. Fused salt electrolysis in melts containing refractory metal fluorides produced parts of complex shape (44). Work was reported on the following methods of metal removal : conventional machining (73, 35, 72), grinding (48, 75), electromethods (56)) and energy-beam processing (42, 47, 56). All of these methods are needed to handle the wide variety of components employed in different applications. Techniques now available for joining the less common metals are indeed a tribute to the ingenuity of modern joining technologists. Diffusion bonding (78, 38, 45) is especially applicable in those cases where recrystallization and grain growth must be avoided. Vacuum furnace brazing (25, 59) was employed to join Mo, Nb, and Ti alloys sensitive to attack by atmospheric gases. Solderability of pure Mo, Nb, Ta, W and of their alloys with Ti, Re, and Zr was investigated (49). Welding rods containing Mo, Nb, and Ti were used with the COZ-shielded arc to join thin stainless steel sheets to parts of much thicker section (47). Electronbeam and laser welding (26, 42, 47) now are subject to much closer control than formerly and, hence, can be used in the production of assemblies of very small or critical dimensions. Ultrasonic welding is another means of securing sound joints with a minimum of disturbed metal (79). As mentioned, publications covering property data constituted a major fraction of the source material monitored. General property information on the less common metals was reviewed (4, 49, 51, 54). Metals of high purity, sometimes in the form of single crystals, often are needed for special applications in which extremely reliable values of intrinsic physical properties, such as electrical resistivity, play an important role. In other applications, strength and oxidation resistance
AUTHOR E. M . Sherwood is Associate Chief, Vapor Deposition Division, Battelle Memorial Institute. He has written I@EC’s Less Common Metals Review each year since 7955.
at high temperatures are paramount. The constitution and structure of alloy systems of the less common metals with Al, B (55); AS, Sb ( 1 2 ) ; and with each other (15) were delineated. New nickel-base superalloys, modified by the addition of Ta, Ti, or W, were developed (28). Mechanical property data described the influence of age hardening on various characteristics ( 1 7 ) and the temperature dependence of plastic flow (71). Physical properties evaluated included modulus of elasticity (3, 27)) resistivity and specific heat (63),superconductivity (2, 74, 20, 34, 36, 37), and thermal expansion (2). A comprehensive study of the use of less common metals as minor alloying agents in 18 Cr-14 Ni stainless steels (66) was conducted to determine their effect on
TABLE I. INFORMATION CATEGORIES 1. Reviews
General information, usually in many of the areas defined below
2.
Extraction
Chlorination, fused-salt electrolysis, ion exchange, leaching, volatilization
3.
Refining
Reduction of pure compounds by active metals, carbon, ana active gases; halides and organometallic decomposition, vacuum treatment
4.
Consolidation
Use of powder-metallurgy techniques, powder
5.
Melting and heating
Consumable-electrode arc melting, electronbeam melting, zone refining, atomization, heat treatment
6.
Working and forming5
Extrusion, explosive forming, forging, rolling, drawing, electroforming, “vapor” forming, shear and conventional spinning
7.
Metal remobala
Conventional machining, grinding, mechanical and chemical polishing, chemical milling, electrodischarge machining, etching, electronbeam and laser machining
8.
Joininga
Adhesive and diffusion bonding, cold welding, soldering, brazing; arc, electron-beam, laser, ultrasonic, and explosive welding; “vapor” joining
9.
Structure and properties
Determination of crystal structure by x-ray, electron, and neutron diffraction; chemical, mechanical, electrical, and thermal characteristics; methods of testing
Corrosion
Attack, or resistance to attack, by various media, usually at or near ambient; high-temperature attack by gases other than oxygen
rolling, gas pressure bonding, casting
10.
11. Oxidation
Attack, or resistance to attack, by oxygen, usually at high temperature; effect of pressure
12.
Protective overlay and diffusion layers, with and for the less common metals; methods of application
Coatings
13. Applications
Current and suggested areas of use
a The term“fabrication” quite often is used to describe metal processing operations involving all of these categories.
susceptibility of this alloy to pitting corrosion. Molybdenum, a t 5% concentration, has the most marked effect in increasing resistance to pitting. Rhenium, when a t levels below 1%, also was very effective. Very thin-e.g. several microns thick-phosphide cases on the “Big Four” (Mo, Nb, Ta, W) refractory metals resisted oxidation at 900’C. for several hours (70). Corner and edge failures occurred sooner, however. The technology of oxidation-resistant coatings for the less common metals was extensively reviewed (7, 27, 22, 53, 65). While silicide- and modified-silicide-base coatings still are receiving major attention, other bases under study include the platinum group metals, oxide VOL. 57
NO. 8 A U G U S T 1 9 6 5
79
Refinements in processing and fabrication of less common metals have
ceramics, borides, nitrides, and carbides. A most closely watched coating application process was chemical vapor deposition. A look also is being taken at the corrosion, wear, and erosion resistance of oxidationresistant coatings. Special coating topics discussed were pack cementation (52), vacuum siliconizing (32), fluidized-bed silicide coatings ( d o ) , “pest” phenomena (68),mechanical properties of coated less common metals (29), diffusion coatings containing boron and carbon (23), and general evaluation techniques for coated metals and alloys ( 7 ) . Finally, the use of the
‘
TABLE I I .
,
Category
1
1
1
2 3 4
1
Berjilium and Berjliium A l i o y ~ 5A, 1811. 20.4, Z l A , 27A, 28.4,
45A 54A QA 14A
REFERENCES-LESS
less common metals as coatings for other materials was reported. Such coatings are applied by chemical vapor deposition j50),by vacuum metallizing (physical vapor deposition) (77), and by electrolytic and electroless deposition (67). In the latter case, attention was also given to the wear resistance of the coatings formed. As a group, the more refractory less common metals have not been widely employed in the chemical process industries. However, examination of source material cited for individual metals, particularly that relating to tantalum and titanium, shows a steady increase in equip-
C O M M O N M E T A L S A N D ALLOYS
~~
Chromium and Chromium Alloys Cafeeory
1
16B 15B
6
34A,46A,47A,57A
748, 178
7
35A, 55A
128
8
72A, 7 6 A , l Q A , 2333 (1964) (73H) Pavll.uk, S. K . , Tuchinskiy, F. X > (74H) Pul’tsin, N. hl., Fiz. M e t . i ,‘detal/oced. 18, 245 (1964). (75H) I’ul’tsin, S . M., Larionor, V. A,, Khim. .Yeti. .lfishznostr. (j),28 (1964). (76H) Rand, M, J., Reimert. L. J., J . Electrochem. Sac. 111, 429 (April 1964). (77H) Raub, C. J., Zwicker, E., Phqs. R Z L137, . A142 (Jan. 4, 1963). (78H) Reimerr, L. J., Rand, hi. J., Ibid., (76H), p . 434. (79H) Rieppel, P.J,, .I. M e t a l s 16, 240 (March 1964). (80H) Rosenthal, A. G., M o d . M e t a l s 20, 27 (May 1164). (81H) Rudiger, O., Knorr, W ~M,e m . Sci. Rev. ,Met. 61, 337 (May 1964). (82H) Sedlacek, V., M e t a l T r e a t . Drop Forging 31, 97 (March 1964). (83H) Segawa, S.: Mori, K., Takamura, A , , Shlrnose, f,,Corrosion Eng. (Tokyo) 1 3 , 2 2 (May 1964). (84H) Idem (46D). (85H) Shishkov, D., Shishkova, L., Comfit. Rend. Acad. Bulgare Sci. 17,243 (1964). (86H) Sparks, R . B., Zucco, J. J., Jr., M a t e r . Design Eng. 60, 91 (Kovember 1964). (87H) Steel 155, 105 (Oct. 19, 1964). (88H) Ibid., 46 (Dec. 21 1964). (89H) Idem (43D). (90H) Idem (48D). (91H) Stringer, J.,J . Less-Cummon .Wetali 6 , 207 (1964). (92H)Suzuki, S., Sxrnitomo Light .tiel01 T e d . Rejt. 5 , 1 (April 1964). (93H) Takeuchi, K., ibid., 30 (January 1964). (94H) Tech. Betreib. 16, 2 5 9 (September 1964). (95H) Idem (66E). (96H) Vagi, J. J., Desaw, F. A , , Weldzng J . 4 3 , 521s (December 1964). (97H) Vonnegut, G. L., Sippel, G. R., Hanink, D . K., AS.V Tech. R e p . \V 4-2.3 (1 964). (98H) Ibid., M e t a l Progr. 86, 119 (September 1964). (99H) Vordahl, M. B., C . S. Patent 3,156,590 (November 10, 1964). (100H) TVaeser, B., .Wetall-Reirzig Vorbshandl. 13, 136 (July 1964). (101H) Wallner, R. L., Williams, B. B., Simmons, A. C., hlater. Protect. 4, 55 (January 1965). (102H) Walters, J. R., Corrorioti Precent. Control 11, 18 (October 1964). (103H) Wang, J. Y. N., .VUG[.Sci. Eng. 18, 18 (January 1964). (104H) Lt’arne, M . A., Moore, D. C., T r a n s . Inst. .Metal F t n d i i n g 41, 9 (Spring 1964). (105H) Weigand, H., Dorst, H. G., D E W Tech. Ber. 4, 140 (1964). (106H) Western .Mach. Steel World 55, 42 (November 1964). (107H) JVilliams, D. Ii.,Wood, R.A,, Jaffee, R. I., Ogden, H. R., J . Less-Common M e t a l s 6 , 219 (March 1964). (108H) Yakimova, A . M.: Metalloaed. i Term. Orabotkn M e t a l . (6), 8 (1964). (109H) Yamane, T . , Ueda: J . , Tranr. Japan Irzrt. .Met& 5 , 43 (January 1964). (IlOH) Zaima, S., Hirayama, T., Light .Wetali (Japan) (63). 50 (January 1964). (111H) Zajma, S., Kamo, S., Ibid., (66), 49 (July 1964).
Tungsten (11) Idem (ID). (21) Aiioy Digest, Sheets \V-8 (December 1964). (31) Baird, W.R., Hartley, C. S., J. Inst. AWetals 92, 181 (February 1964).
(41) Idem (5D). (51) Barth V. D., Defense Metals Inform. Center Rev. Recent Developments (Februaty 1964). (61) Ibid., (May 15, 1964). (71) 1 6 4 (511, (October 30, 1964). (81) Bartletr, R . IV., Trans. .We,+. Soc. A I M E 230, 1097 (August 1964). (91) Basche, M., M u t e r . Design Eng. 6 0 , 82 (August 1964). (101) Idem (6D). (111) Buddenhagen, D. A,, SAE J . 72, 40 (March 1964). (121) Climax Molybdenum Co., Tunesten N e ~ ~ s rNew , York, N. Y . (March 1964). (131) COX,F. G., Eng. M a t e r . D&gn 7, 87 (February 1964). (141) Eisenlohr, A., Metal Progr. 85, 94 (April 1964). (151) Idem (19D). (161) Idem (21D). (171) Idem (20E). (181) Idem (6G). (191) Gibson, I. W., Hein, R . A., Phjs. Rev. Letters 12, 688 (June 22, 1964).
84
INDUSTRIAL A N D ENGINEERING CHEMISTRY
(201) Gross, P.M., Gugliotta, J., Krysiak, K. F., Gross, L. B., Trans. Inslr. Sac. A m . 3, 305 (October 1964). (211) Hayden, H. W., Brophy, J. H., J . Less-Common Metals 6 , 214 (March 1964). (221) Iron Age 193, 78 (January 16, 1964). (231) Idem (31E). (241) Klyachko L. I Semenova, M. P., Besolova, N. K., Poroshkovaya Met. .4knd. .vauk r;kr, (5),’57 (1964). (251) Idem (32E). (261) McCawle)-, F. X., Kenahan, C. B., Schlain, D., U. S. Bur. Mines Rept. Invest. 6454 (1964). (271) McGregor, W.P., Machinerj 70, 97 (July 1964). (281) McGregor, W.P., Mach. M o d . (France) (668j, 8 3 (November 1964). (291) Marzano, C., P/atin,q 207, (March 1964). (301) Matr, R. E., Yoshioka, I., M e t n l . Progr. 85, 9 5 (April 1964). (311) Maykuth, D. J., Ratliff, J. L., Ogden, H. R.,M e t a l Progr. 85, 109 (June 1964). (321) Metal Ind. (London) 104, 314 (March 5, 1964). (331) Idem ( 3 9 4 . (341) Ratliff, J. L., hlaykiith, D. J., Ogden, H. R., Jaffee, R. I., T r a n s . M e t . Soc. AI.WE 290, 490 (April 1964). (351) Rohelotto, S. M., S A E J . 72, 54 (February 1964). (361) Robinson, A. T., AS.1.I T r a n s . Quart. 57, 650 (September 1964). (371) Idem (85H). (381) Schulrz, H . , Acta d\ldet. 12, 649 (May 1964). (391) Idem (47D). (401) Taylor, J. L., J.Less-Common Metals 7, 278 (October 1964). (411) Tedder, O., Iron @Steel (London) 27, 145 (ilpril 1964). Metollooed. i Term. Obrnbotka Metnl. (4) (421) Voytovich, R. F., Lavrenko: V. .4., 50 (1964). .stgren, R. C., Thompson, V. R.: Trans. M e t . Soc. A I M E 230, 931 (June
~.rii
(441) \.%‘hire, J. E., ASM Trans. Quart. 5 7 , 756 (September 1964).
Zirconium (1J) Idem (1H). (2J) Alloy Digest, Sheets Zr-I (October 1964). (35) Bassi, A . , Camona, G., Energie i Y u d 11, 370 (July 1964). (45) Benedict, U., Huer, J.-J.>2. Metallk. 55, 261 (May 1964). (5J) Idem (7D). (65) Caretta, E., D i Pietro, R., Sesini, R., Energie ~Vucl.11, 505 (September 1964). (75) Cobb, H. M., U. S. Patent 3,161,950 (Dec. 22, 1964). (85) Davidson, T. E., Defense Metals Inform. Cenrer Rept. 199, 25 (Mar. 2, 1964). (9J) Idem (14E). Fisch, H. A , . J . Electrochem. Soc. 111, 787 (July 1964). (10J) Douglass, D. L.? (1lJ) Dyce, 1. H., rVticl. Erig. 9, 253 (July 1964). (12J) Idem ( 8 G ) . (133) Fishlock, D., .\fetalwork?ng Prod. 108, 8 6 ( l f a r c h 11, 1964). (14J) Idem (28H). (15J) Idem (35H). (165) Hanson, C. G., Rivlin, V. G., Hart, B. A,, J . AVuc!,Mater. 12, 83 (May-June, 1964). (175) Idem (26E). (18.T: Hussey, R. J., Smeltzer, !\., W‘.,J . Electrochem. SOC. 111, 564 (May 1964). (l9J) Ibid., 1221 (November 1964). (205) Ioffe, V. G., I r v . Vjsshikh L‘chebn. Znvederzii, Tscetn. M e t a l . (3), 133 (1964). (21 J) Ivanov. L. I., Yanushkevich, V. A,: Fir. .Ifeta/. i .hfetallooed. 17, 112 (January 1964). (225) Kass, S., Grozier, J. D., Corrosion 20, l 5 8 t (hlay 1964). (23J) Karo, H., Sroope, D. J., Carver, M . D., U. S. Bur. Mines Refit, Invest. 6536 (1964). (24J) Kidson, G. V.. Miller, G. D., J . Sucl. .Mater. 12, 61 (May-June, 1964). (25.I) Leach, J. S. L., Nehru, A. Y., J.Electrochem. Sac. 111, 781 (July 1964). (265) Idem (60H). (27J) Idem (40E). (285) Idem (41E): ( 2 9 J ) Idem (44E). (305) Idem (69H). (31 . JI. Iiieto. h i . M.. Russell. A. Si., . J . Abpl. .. Phys. . 35, 461 (February 1964). (32J) Iiomura: S., Ito, N., Itami, H., Akutsa, C., J . A t . Energy Soc. J ~ p ~6,f l 28 (January 1964). (33J) O’Donnell, W ,J., Langer, B. F., ,Vu.cl. Sci. Eng. 20, 1 (September 1964). (34Jj Idern (70H). (355) Ostberg, C. G., A c t a M e t . 12, 947 (August 1964). (36J) Idem (52E). (375) Idem (39.4). (385) Pechin, \%’. H., Williams, D. E., Larsen, \V, L., A S M Trans. Quurt. 57, 464 (June 1964). (395) Idem (42D). (40J) Rauschenbach, R., Spindler, H., Kernenergze 7, 19 (January 1964) (415) Idem (58E). (425) Rasler, U., U. S. Patent 3,150,972 (September 29, 1964). (435) Idem (83H). (445) Idem (65E). (455) Thome, P., Soudage Tech. Connexeei 18, 417 (Nov.-Dec, 1964). (46J) \\‘allwork, G. R., Smeltzer, W.TV., Rosa, C . J., Acta M e t . 12, 409 (April 1964). (475) Weinsrein, D., Holtz. F. C., ASM Trans. Quuit. 57, 284 (March 1964). (48.1) )Vestlake. D . G., Acta M e t . 12, 1373 (December 1964). (495) Idem (71E). (50J) Zimmermann, H. G., .I. ALr!. Mater. 19, 247 (Feh.-Star., 1964). \~
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