Abstract: It was proposed that fabricating intermetallics with the rapid-solidification technique for micro-crystalline alloys would be a promising way to develop high-performance materials. A Ni₃Al(Cr) base micro-crystalline alloy, strengthened and stabilized by M₃B₂ boride particles, was designed and prepared. The alloy has a uniform sub-micron-scale refined micro-structure, which is stable without coarsening even after 1000℃ anneal when subjected to high temperature. It retains a high hardness of HV≈580 from room temperature up to at least 650℃, which is related to the characteristic high temperature strength of Ni₃Al phase and the strengthening effect of M₃B₂ particles.

Key words: microcrystalline alloy, in-situ composite materials, rapid solidification, Ni₃Al