热疲劳环境下多元Al-7.5Si-4Cu合金的裂纹萌生扩展  

Crack Initiation and Propagation of Multicomponent Alloy Al-7.5Si-4Cu in Thermal Fatigue Environment

作　　者：陈立佳[1] 

机构地区：[1]唐山学院,河北唐山063020

出　　处：《铸造技术》2015年第8期1955-1958,共4页Foundry Technology

摘　　要：研究了多元Al-7.5Si-4Cu合金在不同热处理状态下的热疲劳性能。结果表明,与铸态试样和淬火+时效热处理试样相比,T6态试样的力学性能最好,微观组织均匀,热疲劳性能最优良。当热循环次数≥10 000时,T6状态与淬火+时效试样由于Si相和A12Cu相的出现降低了裂纹扩展速率,铸态试样由于A12Cu相复熔球的存在导致裂纹扩展速率急剧上升。The thermal fatigue properties of the multicomponent alloy Al-7.5Si-4Cu with different heat-treatment states were investigated. The results show that the mechanical properties of the alloy with T6 state are best, the microstructure is the most uniform and the thermal fatigue properties are also best, compared with those of the samples with both as-cast and quenching ＋ aging states. The crack propagation rates of the samples with T6 and quenching ＋ aging states decrease due to the existence of the phases Si and A12 Cu, while the crack propagation rate of the as-cast sample increases rapidly due to the present of the complex molten balls A12 Cu.

关 键 词：热疲劳 Al-7.5Si-4Cu合金 裂纹萌生及扩展 

分 类 号：TG146.21[一般工业技术—材料科学与工程]