The Microstructures and Mechanical Properties of Molybdenum Disilicide Preforms Infiltrated by Aluminum

Abstract

Infiltrant aluminum was infiltrated into molybdenum disilicide preforms in N2 atmosphere at different temperatures by liquid reactive infiltration processing. The mechanical properties and phase composition of these materials were analyzed and discussed. The experimental results showed that the samples were corresponding to 10 at.% Al averagely after sintered, and consisted of Mo(Al,Si)2 phase and Al-Si alloy phase. High infiltration temperature would lead to Al deficiency mainly in Al-Si alloy phase. The highest bending strength of 737 MPa was reached at infiltration temperature of 1350 °C because the sample had fine and integrated grains, and the strong combination between particles. When the infiltration temperature was higher than 1350 °C, the bending strength of material prepared would decrease because of the phase fragmentation.