Mechanical performance and thermal shock resistance of alumina composites fabricated by temperature gradient spark plasma sintering

Abstract

Temperature gradient spark plasma sintering technology (TGSPS) was used to fabricate alumina composites with addition of tremolite. The mathematics model of TGSPS was established using piecewise interpolation spline function. Liquid phase sintering took place in the sintering process. Vickers hardness, fracture toughness and flexural strength of the composites were measured. Microstructure observations on fracture surfaces of alumina composites were analyzed. Thermal shock resistance of alumina composites was investigated by measuring the strength retention after varying the temperature difference through the water-quench method. Results showed that the addition of tremolite could promote the liquid phases sintering of alumina composites, decrease the porosity, strength the grain boundaries, improve the mechanical properties, and thus contribute to the improvement in TSR of alumina composites.