As a rule, Ir-based alloys are prepared by arc-melting process. Although high density is achieved, the alloys have very large crystal grains due to high temperature and slow cooling rate during melting. The large crystal grains may lead to intercrystalline cracking under deforming, which is one of drawbacks of arc-melting method. Powder metallurgy (P/M)
processing is proved to be an effective method to prepare refractory materials (such as W, Mo etc.) with fine crystal
grains and homogeneous structure which is beneficial to deformation working. Therefore, an attempt is made to prepare
Ir-4Zr-0.3W alloys by P/M method and to analyse their microstructures in this paper.