THE MICROSTRUCTURE AND ROOM TEMPERATURE DUCTILITY OF RAPIDLY SOLIDIFIED(Ni, Fe)Al INTERMETALLICS

The microstructure and bend ductility at room temperature of the (Ni, Fe)Al intermetallic compound were investigated by single roller rapid solidification technology. The results show that under rapid solidification Al-45Ni-5Fe formed equiaxed grains with needle sub-grains less than 1μm, and the bend ductility can reach as high as 3.1 %. The microstructure of Al-35Ni-15Fe and Al-25Ni-25Fe are column grains, and their bend ductility are only 1. 1 % and 1 .0% respectively. The needle sub-grains are metastable phase which can be formed only under the condition of certain composition and rapid solidification, its formation mechanism has close relation with atoms diffusion and vacancy during rapid solidification.