Abstract
Fine-grained sintered molybdenum alloys dispersed with TiC, ZrC, HfC or TaC particles of 0.8 mol.% were prepared by mechanical alloying and hot isostatic pressing. The grain sizes of molybdenum and the particle sizes of carbide particles in the alloy were 0.2-10μm and 20-100 nm, respectively. Grain growth of the alloy was measured to evaluate the stability of the fine-grained microstructure at 1670 K to 2470 K. The following results were obtained.
(1) The grain growth was inhibited significantly more in the molybdenum alloy with carbide particles than in puremolybdenum. The grain growth stopped in 3.6-36 ks.
(2) The dispersion of the ZrC or HfC particles in the alloy was more efficacious against inhibition of grain growth than the dispersion of the TaC or TiC particles.
(3) The grain boundary character distribution in the alloys showed almost no change even after heated at high temperature of 2070K.
