Sc对金属型铸造Al-Si-Cu-Mg合金疲劳行为的影响  

Influence of Sc on fatigue behavior of permanent-mould casting Al-Si-Cu-Mg alloy

作　　者：车欣[1] 陈立佳[1] 李锋[1] 

机构地区：[1]沈阳工业大学材料科学与工程学院,沈阳110870

出　　处：《沈阳工业大学学报》2012年第4期402-406,共5页Journal of Shenyang University of Technology

基　　金：辽宁省高等学校优秀人才支持计划项目(LR201030)

摘　　要：为了确定稀土元素Sc对金属型铸造Al-Si-Cu-Mg合金低周疲劳行为的影响规律,针对含Sc和不含Sc的金属型铸造Al-Si-Cu-Mg合金的低周疲劳行为进行了对比研究.结果表明,当外加总应变幅较高时,金属型铸造Al-Si-Cu-Mg合金和Al-Si-Cu-Mg-Sc合金均呈现循环应变硬化现象,而在低的外加总应变幅下,稀土元素Sc对合金的循环应力响应行为产生较大影响,其中Al-Si-Cu-Mg合金在疲劳变形初期表现为循环应变硬化,在疲劳变形后期则表现为循环稳定,而Al-Si-Cu-Mg-Sc合金在整个疲劳变形期间均发生循环应变硬化.此外,稀土元素Sc的加入可以有效提高金属型铸造Al-Si-Cu-Mg合金的循环变形抗力和低周疲劳寿命.In order to determine the effect of rare earth element Sc on the low-cycle fatigue behavior of the permanent-mould casting Al-Si-Cu-Mg alloy,the low-cycle fatigue tests were performed for the permanent-mould casting Al-Si-Cu-Mg alloys with and without adding Sc.The results show that at the higher total strain amplitudes,both permanent-mould casting Al-Si-Cu-Mg and Al-Si-Cu-Mg-Sc alloys exhibit the cyclic strain hardening.However,the rare earth element Sc has greater influence on the cyclic stress response behavior of the alloy at the low total strain amplitude.For the Al-Si-Cu-Mg alloy,the cyclic strain hardening occurs at the initial stage of fatigue deformation,and the cyclic stability is noted at the later stage of fatigue deformation.However,the cyclic strain hardening is observed during the whole fatigue deformation for the Al-Si-Cu-Mg-Sc alloy.Furthermore,the addition of rare earth element Sc can effectively enhance the cyclic deformation resistance and prolong the fatigue lives of the permanent-mould casting Al-Si-Cu-Mg alloy.

关 键 词：AL-SI-CU-MG合金 稀土元素Sc 金属型铸造 低周疲劳 疲劳寿命 循环应力响应 循环应变硬化 循环稳定 

分 类 号：TG146.2[一般工业技术—材料科学与工程]