稀土La变质Al-12.35Si合金的组织及性能  

Microstructure and Properties of Al-12.35Si Alloy Modified by Rare Earth La

作　　者：史攀 冯增建 崔岩寿 李艳军 刘志伟[1] Shi Pan;Feng Zengjian;Cui Yanshou;Li Yanjun;Liu Zhiwei(State Key Laboratory for Mechanical Behavior of Materials,School of Materials Science and Engineering,Xian Jiaotong University;Binzhou Bohai Piston Co.,Ltd.)

机构地区：[1]西安交通大学金属材料强度国家重点实验室,材料科学与工程学院,西安710049 [2]滨州渤海活塞有限公司

出　　处：《特种铸造及有色合金》2020年第7期704-709,共6页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(51974224);西安交通大学基本科研业务费资助项目(xtr0118008,xjj2018002)。

摘　　要：通过添加Al-La中间合金的方式对含多种合金元素的Al-12.35Si合金进行稀土La变质处理,研究La含量(0.1%~0.8%)对其微观组织及力学性能的影响。结果表明,适量La可以减小长针状共晶Si尺寸,细化第二相组织,减小初生α-Al二次枝晶臂间距。过量La可引起过变质,致使合金组织粗化。当La含量为0.2%时,Al-Si合金凝固组织变质效果最为理想且其力学性能最佳,抗拉强度从168MPa提高至188MPa,伸长率从0.44%提高到0.53%;随着La含量继续增加,合金强度及塑性下降。Near-eutectic Al-12.35Si alloy containing various alloying elements was modified by the rare earth La element through adding the Al-La master alloy,and effects of the addition amount(0.1%~0.8%)of La on the microstructure and mechanical properties of Al-Si alloy were investigated.The results reveal that the proper addition amount of La can reduce the size of long needle-like eutectic silicon,refine the second phase,and reduce the primaryα-Al secondary dendrite arm spacing(SDAP).Excessive La can cause excessive deterioration,resulting in coarsening of the alloy structure.When the La content is 0.2%,the Al-Si alloy has the desirable modified solidification structure and mechanical properties,where the tensile strength of alloy is increased from 168 MPa to 188 MPa,and the elongation is increased from 0.44%to 0.53%.With the increase of La content,both the strength and plasticity of the alloy are declined.

关 键 词：近共晶Al-Si合金 变质 稀土La 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]