Investigations on the NiAl–Cr(Mo) eutectic alloy with optimized microstructure and improved room-temperature compressive properties

In this paper, microstructural optimization was chosen to strengthen NiAl-based alloys based on hot pressing sintering of pre-alloyed powders. The Cr(Mo) phase in the eutectic cell was refined to 200 nm successfully. Owing to the growth of the Cr(Mo) phase, the volume fraction of the eutectic cells greatly reduced. The compact sample has been obtained at a relatively lower temperature and an extended holding time to retain the eutectic cells. Each compact sample shows considerable performance both in strength and plasticity for compression test at room-temperature. The grown Cr(Mo) phase which can resist the cracks and the eutectic cells with nano-sized Cr(Mo) phase are the main reasons for toughening and strengthening. The improvement of strength and plasticity of alloy in this paper can provide basic understanding for further development of NiAl-based alloy.