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Room temperature reduction of scheelite (CaWO4)

Published online by Cambridge University Press:  31 January 2011

N. J. Welham
N. J. Welham
Affiliation:
Petrochemistry and Experimental Petrology, Research School of Earth Sciences and Department of Electronic Materials Engineering, Research School of Physical Sciences and Engineering, Australian National University, Canberra. ACT 0200, Australia
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Abstract

A mixture of scheelite and magnesium has been mechanically milled together for 100 h, either with graphite or in a nitrogen atmosphere, with the intention of forming tungsten carbide or nitride. The resultant powders were examined by thermal analysis, isothermal annealing, and x-ray diffraction to determine the effect of milling on the reduction of scheelite. With graphite, nanocrystallite W2C was the exclusive tungsten product; WC was not detected even after annealing at 1000 °C. No nitride formed in the system milled with nitrogen; however, 10 nm crystallites of elemental tungsten were formed. The unwanted phases, MgO and CaO, were readily removed by leaching in acid, leaving a fine powder composed of impact welded aggregates of either carbide or 99% pure tungsten metal.

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Journal of Materials Research , Volume 14 , Issue 2 , February 1999 , pp. 619 - 627
Copyright
Copyright © Materials Research Society 1999

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References

REFERENCES

1.Stephen, W.H., Tungsten (Plenum Press, New York, 1979), pp. 215–219.Google Scholar
2.Matteazzi, P. and Le Caër, G., J. Am. Ceram. Soc. 74, 1382–1385 (1991).Google Scholar
3.Wang, G.M., Millet, P., Calka, A., and Campbell, S. J., Mater. Sci. Forum 179–181, 183–188 (1995).CrossRefGoogle Scholar
4.Xueming, M. and Gang, J.I., J. Alloys Comp. 245, L30–L32 (1996).Google Scholar
5.Ma, X. M., Ling, Z., Gang, J., and Dong, Y. D., J. Mater. Sci. Lett. 16, 968–970 (1997).CrossRefGoogle Scholar
6.Wang, G.M., Campbell, S.J., Calka, A. and Kaczmarek, W.A., J. Mater. Sci. 32, 1461–1467 (1997).CrossRefGoogle Scholar
7.Atlas of Microstructures of Industrial Alloys (American Society of Metals, Metals Park, OH 1972), pp. 127–128.Google Scholar
8.Terry, B. S. and Azubike, D. C., Trans. Inst. Min. Metall. C 99, 175–182 (1990).Google Scholar
9.Terry, B. S., Azubike, D. C., and Chrysanthou, A., J. Mater. Sci. 29, 4300–4305 (1994).Google Scholar
10.Johnston, R. F. and Hguyen, H. T., Min. Eng. 9, 765–773 (1996).CrossRefGoogle Scholar
11.Welham, N. J., Mater. Sci. Eng. A, 248, 230–237 (1998).CrossRefGoogle Scholar
12.Villars, P. and Calvert, L. D., Pearson's Handbook of Crystallographic Data for Intermetallic Phases (American Society for Metals, Metals Park, OH, 1985), p. 3258.Google Scholar
13.Ensinger, W. and Kiuchi, M., Surf. Coat. Technol. 84, 425–428 (1996).Google Scholar
14.Veprek, S., Haussmann, M., and Reiprich, S., J. Vac. Sci. Technol. A–Vac. Surf. Films 14, 46–51 (1996).CrossRefGoogle Scholar
15.Samsonov, G. V. and Vinitskii, I. M., Handbook of Refractory Compounds (Plenum Press, New York 1980), p. 555.CrossRefGoogle Scholar
16.Schwartzkopf, P. and Kieffer, R., Refractory Hard Metals: Borides, Carbides, Nitrides and Silicides (Macmillan, New York, 1953), p. 447.Google Scholar
17.Palmetshofer, L and Rodhammer, P., Nucl. Instrum. Methods in Phys. Res. B 1, 340–343 (1993).CrossRefGoogle Scholar
18.Hurkmans, T., Trinh, T., Lewis, D. B., Brooks, J. S., and Munz, W. D., Surf. Coat. Technol. 76, 159–166 (1995).Google Scholar
19.Nagai, M. and Kishida, K., Appl. Surf. Sci. 70–1, 759–762 (1993).Google Scholar
20.Chiu, H.T. and Chuang, S. H., J. Mater. Res. 8, 1353–1360 (1993).Google Scholar
21.Kim, Y.T., Lee, C. W., and Min, S. K., Jpn. J. Appl. Phys. Part 1 32, 6126–6131 (1993).CrossRefGoogle Scholar
22.Lee, C.W., Kim, Y. T., and Min, S. K, Appl. Phys. Lett. 62, 3312–3314 (1993).CrossRefGoogle Scholar
23.Parkin, I. P. and Rowley, A. T., J. Mater. Chem. 5, 909–912 (1995).Google Scholar
24.Baxter, D.V., Chisholm, M. H., Distasi, V. F., and Haubrich, S. T., Chem. Mater. 7, 84–92 (1995).Google Scholar
25.Chen, X.Z., Dye, J.L., Eick, H. A., Elder, S. H., and Tsai, K. L., Chem. Mater. 9, 1172–1176 (1997).CrossRefGoogle Scholar
26.Calka, A. and Nikolov, J.I., Mater. Sci. Forum 179–181, 333–338 (1995).Google Scholar
27.Calka, A., Nikolov, J. I., Li, Z. L., and Williams, J.S., Mater. Sci. Forum, 179–181, 295–300 (1995).Google Scholar
28.Kerr, A., Welham, N. J., and Willis, P. E., Nanostruct. Mater. (1998, in press).Google Scholar
29.Welham, N. J., Kerr, A., and Willis, P. E., J. Am. Ceram. Soc. (1998, in press).Google Scholar
30.Willis, P. E., Welham, N. J., and Kerr, A. J., J. Euro. Ceram. Soc. 18, 701–708 (1998).CrossRefGoogle Scholar
31.Roine, A., HSC Chemistry for Windows; Outokumpu Research Oy: Pori, 1994.Google Scholar
32.Bard, A. J., Parsons, R., and Jordan, J., Standard Potentials in Aqueous Solution (Marcel Dekker, New York, 1985), p. 834.Google Scholar
33.Calka, A. and Radlinski, A. P., Mater. Sci. Eng. A134, 1350–1353 (1991).CrossRefGoogle Scholar
34.Warren, B. E., X-Ray Diffraction (Dover, New York, 1990), pp. 251–314.Google Scholar
35.Klug, H. P. and Alexander, L. E., X-Ray Diffraction Procedures (John Wiley, New York, 1954), p. 716.Google Scholar
36.Storms, E.K., The Refractory Carbides (Academic Press, New York, 1967), pp. 1–17.Google Scholar
37.Koch, C.C., Nanostruct. Mater. 9, 13–22 (1997).Google Scholar
38.Welham, N.J., Trans. Inst. Min. Metall. C 106, 141–144 (1997).Google Scholar
39.Welham, N.J. and Llewellyn, D. J., Min. Eng. 11, 827–841 (1998).Google Scholar
40.Welham, N.J., Metall. Mater. Trans. B 29, 603–610 (1998).Google Scholar
41.Wang, G.M., Campbell, S.J., Calka, A., and Kaczmarek, W.A., Nanostruct. Mater. 6, 389–392 (1995).Google Scholar
42.Campbell, S.J., Wang, G.M., Calka, A., and Kaczmarek, W.A., Mater. Sci. Eng. A 226, 75–79 (1997).Google Scholar
43.Welham, N.J. and Williams, J. S., Carbon, 36, 1309–1315 (1998).CrossRefGoogle Scholar
44.Welham, N.J., J. Mater. Sci. (1998, in press).Google Scholar
45.Di, L.M., Calka, A., Li, Z. L., and Williams, J. S., J. Appl. Phys. 78, 4118–4122 (1995).CrossRefGoogle Scholar
46.Lide, D.R., Handbook of Chemistry and Physics (CRC Press, Boca Raton, FL, 1992), p. 5.92.Google Scholar
47.Williams, J. S., personal communication, 1997.Google Scholar
48.Tkacova, K., Mechanical Activation of Minerals (Elsevier, London, 1989), p. 179.Google Scholar
49.Maurice, D. and Courtney, T. H., Metall. Mater. Trans. A 27, 1981–1986 (1996).Google Scholar
50.Ding, J., Tsuzuki, T., McCormick, P. G., and Street, R., J. Magn. Magn. Mater. 162, 271–276 (1996).Google Scholar