摘要
通过成分设计,铸造出不同稀土Er含量的6063铝合金。采用光学显微镜、扫描电镜(SEM、EDS)、XRD、维氏硬度计等手段研究了稀土Er铝合金铸态微观组织与性能,从理论上分析了Er的作用机理。结果表明,当Er的含量为0.4%时合金的晶粒细化效果最明显,硬度增幅达到最大值,而当含量超过0.4%时,细化效果减弱,硬度值逐渐降低。在6063铝合金熔铸凝固过程中,大部分Er偏聚于合金的晶界处,形成粗大的金属间化合物A l3Er相,有强化晶界、阻止晶粒长大作用;小部分Er与A l生成次生金属间化合物,弥散分布于基体中,产生弥散强化作用,并在形核时充当形核剂,从而可细化晶粒。
The 6063 aluminium alloys with different Er content were prepared after composition design.The microstructure and properties of Er-Al alloy as-cast were investigated by an optical microscope,SEM,EDS,XRD and Vickers hardness tester.The effect mechanism of Er was theoretically analyzed.Results show that when Er content reaches 0.4%,the grain refining effect is best and the hardness increment is the most;when Er content over 0.4%,the grain refining effect is weaken and the hardness decrease gradually.In the course of solidification,most Er is segregated at grain boundaries,and forms coarse intermetallics Al3Er which lead to strengthening grain boundaries and inhibiting grain growth.A little portion Er and Al form into secondary intermetallics which dispersedly distribute in the substrate and strengthen the substrate.This dispersed phase works as nucleating agents and refines grains.
出处
《金属热处理》
CAS
CSCD
北大核心
2011年第2期21-25,共5页
Heat Treatment of Metals
基金
广西区自然科学基金项目(0728209)
广西科学研究与技术开发计划项目(桂科攻0815001-8)
关键词
6063铝合金
稀土铒
细化晶粒
组织与性能
6063 aluminium alloy
rare earth element Er
grain refinement
microstructure and properties
