Simultaneous improvement of the strength and fracture toughness of MgO-Al2O3-SiO2 glass/Mo composites by the microdispersion of flaky Mo particles

The effect of shape and volume percent of Mo particles on the flexural stre ngth and fracture toughness of MgO-Al2O3-SiO2 (MAS) glass/Mo composites was investigated. The flexural strength and fracture toughness of composites d epends heavily on Mo particle shapes, and there is greater improvement in c omposites reinforced with flaky rather than massive Mo particles. In the co mposites reinforced with flaky Mo particles, fracture toughness increases w ith volume percent of Mo and, at 50 vol% Mo, is 11.6 MPa root m, which is a pproximately 6.7 times higher than that of the matrix. Increases in fractur e toughness of composites reinforced with flaky Mo particles is greater tha n with SiC whiskers, SiC platelets, SiC particles or ZrO2 particles. Fabric ating composites reinforced with flaky Mo particles is an effective toughen ing technique capable of simultaneously improving the strength and toughnes s of brittle materials, such as monolithic Al2O3 and MAS glass, by utilizin g plastic deformation of ductile phase. (C) 2000 Kluwer Academic Publishers .