高速客车SiCp/A356铝基制动盘材料的热疲劳裂纹形成与扩展试验研究  

The Test Research of Thermal Fatigue Crack Initiation and Propagation of SiCp/A356 for Brake Discs of High-speed Trains

作　　者：杨月[1] 谢基龙[1] 

机构地区：[1]北京交通大学机械与电子控制工程学院,北京100044

出　　处：《铁道学报》2007年第5期43-47,共5页Journal of the China Railway Society

基　　金：国家高技术研究发展计划(863计划)项目(2003AA331190)

摘　　要：在室温25℃-360℃自约束型热循环条件下,研究SiC增强颗粒体积分数为20%的铝基复合材料SiCp/A356的热疲劳裂纹形成与扩展特性,并且探讨了复合材料热疲劳裂纹的形成机制和扩展过程。研究结果显示,试样的切口尺寸对裂纹形成有很大的影响,而对裂纹扩展阶段的影响可以忽略,但试样厚度对裂纹的扩展有影响。通过非线性有限元顺序耦合法仿真计算了热疲劳裂纹尖端应力应变场,确定热疲劳裂纹扩展的驱动力为低温点的拉应力,因而认为,结合本次实验结果并通过断裂力学分析方法可以对颗粒增强金属基复合材料的热疲劳裂纹的扩展行为做进一步的研究。The thermal fatigue crack initiation and propagation characteristics of A1-Matrix Composites Vol. 20%SICp/A356 are studied with the finite element computation method in the self-restraint thermal fatigue test under the conditions of cycling at the room temperature from 20℃ to 360℃. The mechanism of crack initiation and process of propagation are discussed. The results show that the notched dimensions of samples have a great effect on crack initiation, but the influence can be ignored during the crack propagation phase; the thicknesses of samples affect crack propagation. All kinds of materials used in brake discs are compared with one another. The stress and strain field of the crack tip is simulated with the nonlinear finite element sequence coupling method, and the tension stress is determined to be the drive force for crack propagation. Combining with the test results, further study on thermal fatigue crack propagation may be made with the method of fracture mechanics.

关 键 词：复合材料 热疲劳 裂纹形成 裂纹扩展 顺序耦合 

分 类 号：TG111[金属学及工艺—物理冶金] TB333[金属学及工艺—金属学]