Creep Properties of Squeeze Infiltrated AS52 Mg/Al_(18)B_4O_(33)w Composite

摘要

Creep behavior of the squeeze infiltrated AS52 Mg matrix composites reinforced with 15 vol percent of aluminum borate whiskers(Al_(18)B_4O_(33)w) fabricated squeeze infiltration method was investigated. Microstructure of the composites was observed as uniformly distributed reinforcement in the matrix without any particular defects of casting pores etc. Creep test was carried out at the temperature of 150 and 200 deg C under the applied stress range of 60-120 MPa. The creep resistance of the composite was significantly improved comparing with the unreinforced AS52 Mg alloy. The creep behavior of composites might be interpreted with the substructure invariant model successfully for the composite. Threshold stress of the composite exist for the creep deformation of the composite. The analysis of the creep behavior of the composite with threshold stress indicated that creep deformation was controlled by the lattice diffusion process of AS52 Mg matrix at given effective stresses and temperatures. Activation energy was also calculated to check lattice diffusion controlled creep behavior of the composite.