Abstract
The effect of heat-treatment in vacuum and hydrogen on the ductility and UTS of the sintered 96W-2.8Ni-1.2Fe (by wt%) heavy alloy has been studied. The elongation of the as-sintered alloy is about 8%, but after a few minutes of heat treatment in vacuum at 800° C it increases markedly to about 19%. When the sintered specimen is heat-treated in vacuum at 600° C, the elongation increases rapidly with time, reaching 20% after about 10 min. The values of UTS also increase after vacuum treatment. Heat treatment in hydrogen, however, shows no change in mechanical properties from the as-sintered state. The effect of vacuum treatment is thus attributed to the removal of hydrogen embrittlement. Based on the hydrogen diffusion model, a practical guide line is suggested for determining the optimum vacuum treatment conditions. The scanning electron micrographs of the fracture surfaces show that hydrogen weakens mainly the interface between tungsten grains and matrix.
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Yoon, H.K., Lee, S.H., Kang, S.J.L. et al. Effect of vacuum-treatment on mechanical properties of W-Ni-Fe heavy alloy. J Mater Sci 18, 1374–1380 (1983). https://doi.org/10.1007/BF01111957
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DOI: https://doi.org/10.1007/BF01111957