Effects of V addition on the microstructures and compression properties of NiAl-Cr alloys

The effects of V addition on the microstructure and compression properties of NiAl-Cr alloys were investigated. V does not change the constituent phases but significantly changes the microstructure morphology. With increasing V content, the microstructures change to be Cr(V) dendrites and NiAl + Cr(V) eutectic. V addition markedly enhances the compression strength due to solid solution strengthening and second phase strengthening. At room-temperature, weak interfacial bonding between Cr(V) dendrites and eutectic as well as the deterioration of eutectic microstructure degrade properties. The room-temperature compression strength initially rise and thereafter decline. The NiAl-28Cr-10V alloy has the highest compression strength of 2350 MPa. At high-temperature, microstructural roughening improves strength, leading to the highest compression strength of 411 MPa in NiAl-28Cr-18V alloy.