摘要
在7136铝合金中添加不同含量的La元素,通过铸态组织观察、力学性能测试、扫描电镜及透射电镜分析等,研究了La元素对7136铝合金组织与性能的影响。结果表明:添加La后,由于La元素原子半径远大于Al元素原子半径,La元素富集在晶界处形成异质形核核心,使晶界熔断、缩小,并成为结晶核心,增加形核率,细化晶粒,提高合金性能;同时La可与合金形成不同键合作用的多种La-Al稀土化合物,其相粒子强烈扎住位错,使合金晶粒及其相邻晶粒难以滑移,再次提高合金性能;添加0.35%La的7136铝合金单级时效时间明显缩短,硬化率提高;伸长率为11.73%,比无添加La的7136合金增加了30.5%。
Effects of La on microstructure and properties of 7136 aluminum alloy were studied by means of as-cast microstructure observation,mechanical properties test,scanning and transmission electron microscope analysis.The results show that after adding La,because the atomic radius of La atom is much larger than that of Al,La element is enriched to form heterogeneous nucleation core at the grain boundary,which makes the grain boundary fuse,shrink and become the crystallization core,increase the nucleation rate,refine the grain size and improve the properties of the alloy.At the same time,La can form a variety of La-Al rare earth compounds with different bonding interactions in the alloy,and its phase particles strongly pin the dislocations,which makes it difficult for the alloy grain and its adjacent grains to slip,and once again improves the properties of the alloy.The single stage aging time of the 7136 aluminum alloy with 0.35%La is obviously shortened,the hardening rate increases and the elongation is 11.73%,which is 30.5%higher than that of the 7136 alloy without La.
作者
王春华
杨丽娟
徐雪芳
房洪杰
吕正风
Wang Chunhua;Yang Lijuan;Xu Xuefang;Fang Hongjie;LüZhengfeng(College of Engineering,Yantai Nanshan University,Yantai Shandong 265713,China;Laboratory of Light Alloy Forming,Yantai Shandong 265713,China;Shandong Provincial Key Laboratory,Yantai Shandong 265713,China;Shandong Nanshan Aluminum Co.,Ltd.,Yantai Shandong 265706,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2019年第11期34-38,共5页
Heat Treatment of Metals
基金
山东省高等学校科技计划项目(J18KB046)
山东省重点研发计划项目(2017GGX20130)
关键词
7136铝合金
组织
性能
LA
晶粒细化
7136 aluminum alloy
microstructure
properties
La element
grain refinement
