Phases Identification by X- Ray Analysis for Liquid Phase Sintered Tungsten Heavy Alloys

Abstract

The objective of this experimental study is to determine and analyze the phases present in tungsten heavy alloy specimens of different chemical compositions and to follow up the evolution of these phases during sintering using X-ray diffraction. On the other hand, X-ray diffraction graphs was used to reveal the effect of sintering parameters and alloy composition on the nature of the diffusion processes that take place among the different constituents present in the alloy. The X-ray diffraction analysis started by the determination of the diffraction patterns of pure elements of the constituents of the alloys used in this experimental study. Then, the X-ray diffraction analysis was performed for liquid phase sintered tungsten heavy alloy, having the composition 93%W-4.9%Ni-2.1%Fe, and sintered at different temperatures. Also, to determine the effect of addition of Cobalt to the matrix constituents, X-ray diffraction pattern obtained using tungsten heavy alloy having the composition 91%W-6%Ni-3%Co was compared with that for the basic alloy prepared in the same conditions. XRD results obtained for this alloy sintered at different temperatures confirmed that with increasing the sintering temperature, the tungsten solubility in the matrix increases resulting in a pronounced solid solution strengthening. Also, the study proves that the presence of cobalt in the solid solution of the matrix suppresses the solubility of tungsten in this matrix.