Synthesis of Dispersion-Hardening Intermetallic Compounds from Elemental Powder Mixture

초록

Dispersion-hardening of intermetallic compounds based on Ni3Al and γ-TiAl was studied. The alloys were consolidated by elemental powder metallurgy in which elemental powders were mixed and densified by hot extrusion. As for the hardening dispersoids, ZrO2 was selected from the consideration of thermal compatibility with the intermetallic matrix. Dispersion hardening effect of ZrO2 was demonstrated experimentally for Ni3Al-B alloy over a broad range of temperature. Further improvement of the tensile properties was sought by using fine grained, partially stabilized zirconia. Although the grain refining effect of the fine zirconia was obtained, this approach resulted in undesirable particle coagulation. Remedies to circumvent the problem were suggested.