颗粒增强SiC_p／2024铝基复合材料的应力腐蚀断裂行为

STRESS CORROSION CRACKING BEHAVIOR OF SiC_p/2024 METAL MATRIX COMPOSITE

通过双悬臂梁试样试验和慢应变速率拉伸试验，研究了ＳｉＣｐ／２０２４铝基复合材料在ＮａＣｌ水溶液中的应力腐蚀断裂（ＳＣＣ）行为，并探讨了增强体的存在对材料ＳＣＣ行为的影响。发现增强体的存在并未使材料的ＳＣＣ机理发生本质上的变化，但使复合材料的ＳＣＣ抗力明显高于普通铝合金的。

By kinetic tests with double cantilever beam (DCB) specimens and slow strain rate tension (SSRT)tests,the stress corrosion cracking (SCC) behavior of SiC. (10pm,15 vo1%)/2024 aluminium mains composite in NaCl solution was investigated. The effect of particulate reinforcement on SCC behavior of this material was discussed. SCC did not occur in both tests in the open circuit condition. However, SCC was observed in the SSRT test under small anodic polarization. Introduction of the particulate reinforcement did not alter the SCC mechanism of intergranular anodic dissolution. The composite exhibited significantly higher SCC resistance than the similarly produced 2024 aluminium alloy. This could be attributed to: 1)the finer grains of matrix of the composite; 2) the strain concentration effect in the mains adjacent to SiC particulates; 3) the hindering effect of the particulates located at the grain boundaries from growing of the intergranular SCC crack.