Dimensional stability in liquid phase sintered W-Ni-Cu alloys

Dimensional stability is a major concern in liquid phase sintered tungsten heavy alloys (WHAs). W-Ni-Cu alloys are ideal for investigating the slumping characteristics owing to the large difference in the solid-liquid density which causes gravity-induced separation. This paper investigates the effect of varying liquid volume fraction, Ni:Cu ratio, and sintering temperatures on the slumping tendency of these alloys. The conditions under which distortion occurs are identified and related to microstructural parameters including the grain size, dihedral angle, and contiguity. These model experiments offer insight into improving the process design for sintering high matrix content tungsten alloys where distortion control is important