Effect of Al Additions on the Microstructure and Properties of MoSi_2-5Nb Prepared by Mechanical Alloying

摘要

The effect of 3-10at.% Al addition on the microstructures and mechanical properties of a MoSi_2-5Nb matrix alloy was studied. Mechanical alloying and pulse discharge sintering (MA-PDS) process were employed to fabricate these alloys. It was found that the aluminum addition may change the crystal structure of the alloys from a tetragonal C11_b to a hexagonal C40 crystal structure. With a composition of MoSi_2-5Nb-5Al a C11_b/C40 a dual phase structure was obtained and this microstructure results in improved mechanical properties at high as well as at room temperature.