SiCp_A356复合材料变温下的力学行为

Mechanical Behavior of SiCp_A356 Composite Matrerial Under Changed Temperature

试验研究了SiCp_A356复合材料在变温条件下的力学行为．结果表明，SiCp_A356复合材料的屈服强度、拉伸强度和弹性模量随温度的升高明显下降．在20℃～150℃之间，表现为循环硬化，且硬化程度随温度升高而减弱；在200℃～300℃之间，表现为循环软化，且软化速率随温度升高不断增大．而松弛行为与一般金属材料通常具有的基本特征相似．在此基础上，建立了适用于制动盘结构分析的热弹塑性-蠕变本构模型，为进行制动盘应力应变场数值模拟和预测寿命提供了前提和基础．此外，还对SiCp_A356复合材料的微观断裂机制进行了分析。

It is shown from the experimentation that the yield stress, tensile stress and Young＇s modulus are decreased obviously while temperature rising; The cycle hardening happens at 20 ℃ ～50 ℃ and the hardening degree weakens while temperature rising. The cycle softening happens at 200 ℃～ 300 ℃ and the softening velocity increases while temperature rising; Its relaxation behavior is similar to metal. Based on these experimentation data, the thermal-elasto-plastic-creep constitutive model is deduced for the brake disc stress-strain analysis and life prediction. In addition, the micro-crack mechanism is also analyzed.