Elevated temperature tensile properties and deformation of directionally solidified NiAl–Mo in-situ composites

Abstract

Four composition NiAl–xMo (x=7.8, 9, 13 and 16at.%) alloys were directionally solidified by a liquid metal cooling technique at a growth rate of 6μm/s. Perfectly aligned fibrous microstructures were fabricated for all four alloys. Tensile properties at elevated temperature were performed. Damage evolution and fracture characteristics at elevated temperature were also investigated. The fracture behavior of the composites in all tensile tests exhibited a ductile behavior at 1000°C. The high temperature tensile strength was found to increase with the volume fraction of Mo rods. The fibers are expected to bear the greater part of the imposed load due to the strong interface of the constituent phases. The Mo fibers' solid solution strengthened by both Ni and Al also contributes to the strength of composite.