The addition of small amount of special metal powders to Mo powder compact is known to be effective for getting high sintered density.
This paper describes the sintering characteristics of Mo powder compacts containing up to 0.8%Ni, 2.0%Fe and 0.6%Co powders, studied by use of density measurement and dilatometric methods. The result obtained is that Ni powder is quite more effective to densificate Mo powder compacts than Fe and Co powders. For example, the dimensional shrinkage of Mo-Ni powder compact starts at low temperature in comparison with Mo-Fe and Mo-Co powder compacts during heating up to 1573 K.
In order to reveal the diffusion processes of Mo powder compacts, diffusion couples of Mo-Ni, Mo-Fe and Mo-Co powder compacts are heated in vacuum up to 1573 K for 3.6 ks, and diffusion zones are examined using EPMA. The result is interpreted as that the mass flow in Mo-Ni diffusion couple is larger than that in Mo-Fe and Mo-Co diffusion couples.