预力学循环对SiCp/2024Al复合材料塑性变形抗力的影响  

Effects of Pre-mechanical Cycling on Plastic Deformation Resistance in a SiCp/2024Al Composite

作　　者：张帆[1] 张国定[1] 李小璀[1] 蒋晓刚[1] 

机构地区：[1]上海交通大学金属基复合材料国家重点实验室,上海200030

出　　处：《材料科学与工程学报》2006年第1期10-12,共3页Journal of Materials Science and Engineering

基　　金：国家自然科学基金(50371054)

摘　　要：实验研究了预力学循环对退火及T6处理状态碳化硅颗粒增强铝基复合材料塑性变形抗力的影响。结果表明,两种热处理状态复合材料的预力学循环效果不同。对退火态复合材料,预力学循环对塑性变形抗力的影响主要取决于力学循环应力幅度σa:在较低σa条件下,宏观屈服强度无明显变化,而少数几个循环即可提高微屈服强度,但循环次数再增多,微屈服强度也基本不变;随σa的升高,宏观及微屈服强度均有较明显的增高;但当σa过高时,将会因微结构损伤造成宏观屈服强度和微屈服强度急剧下降,即存在一个最佳的σa,使各级塑性变形抗力达到最高。对T6态复合材料,预力学循环提高塑性变形抗力的效果不佳。Effects of pre-meehanieal cycling （PMC） on plastic deformation resistance of annealed and T6 treated SiCp/2024Al composites were investigated experimentally. The results show that the effects of the PMC were different for the two heat treated composites. For the annealed composite, the effect of the PMC on plastic deformation resistance was dependent to cyclic stress amplitude （ σs）. In the case of a lower σs, the PMC had no effect on macroyield strength （YS） of the composite, but could raise its microyield strength （MYS） within first a few cycles. With increase in the σs, the YS and MYS all increased. As the σs was, however, over a critical value, the MYS and YS of the composite all dropped dramatically. For the T6 treated composite, the PMC was basically not beneficial to the plastic deformation resistance.

关 键 词：金属基复合材料 预力学循环 塑性变形抗力 微屈服 热处理 

分 类 号：TB331[一般工业技术—材料科学与工程]