Al_2O_3sf／LY12复合材料在高温下的流动应力与塑性变形行为

FLOW STRESS AND PLASTIC DEFORMATION BEHAVIOR OF AAl_2O_3 SF/LY12 COMPOSITE AT ELEVATED-TEMPERATURE

采用固态高温压缩试验、高温金相观察等试验手段，实验研究了Ａｌ２Ｏ３ｓｆ／ＬＹ１２复合材料在高温下的流动应力与塑性变形行为。结果表明，随着变形温度的提高，由于基体的变形抗力以及基体对阻碍其变形的纤维的剪切作用力大大降低，纤维不易产生断裂并易于以偏转的形式调整自己的方位来适应基体的塑性流动，从而显著降低复合材料的流动应力和大大提高其塑性和变形能力，有利于复合材料的成形。

he flow stress and plastic deformation behavior of Al2O3 sf/LY12 composite at elevated-temperature were experimentally investigated by means of elevated-temperature compression test and microstructureobservation of the composite during compression.It was revealed that,with the enhancement of the deformation temperature,the now stress of the composite falls rapidly while its plastic deformability is greatly improved due to the decrease at higher temperature of both the deformation resistance of the matrix and the deformation-induced shear force acting on the fibers hindering the matrix deformation,which,in consequence,leads to less tendency for the fibers to fracture and more conveniency for them to deflect and orient themselves to matrix plastic deformation.