摘要
研究了等温温度、保温时间和变形量对Mg-6Al-0.9Er合金组织与性能的影响,并对比分析了等温热处理前后Mg-6Al-xEr的拉伸和冲击性能。结果表明,不同等温温度下Mg-6Al-0.9Er合金的组织都由白色基体α-Mg和灰黑色β-Mg_(17)Al_(12)相组成,随着等温温度的升高,α-Mg枝晶逐渐转变为球晶,圆整度提高、晶粒变小,Mg-6Al-0.9Er合金的显微硬度呈现逐渐升高的趋势;随着等温时间的延长,Mg-6Al-0.9Er合金的晶粒逐渐圆整和细化,并在等温时间为15min时形成了完整等轴晶,显微硬度呈现逐渐升高的趋势;随着压缩变形量的增加,合金晶粒趋于圆整化,Mg-6Al-0.9Er合金的显微硬度呈现逐渐升高的趋势。添加Er有助于提升铸态Mg-6Al合金的室温拉伸性能和冲击韧性,且经过压缩变形量20%、550℃/15 min等温热处理后,等温热处理态Mg-6Al-0.9Er合金抗拉强度、断后伸长率、断面收缩率和冲击韧性比铸态分别提高了11.3%、32.6%、3.8%和23.3%。
The effects of isothermal temperature,holding time and deformation on the structure and properties of Mg-6Al-0.9Er alloy were studied,and the tensile and impact properties of Mg-6Al-xEr alloy before and after isothermal heat treatment were compared and analyzed.The results show that,the microstructures of Mg-6Al-0.9Er alloys at different isothermal temperatures are composed of white matrix alpha-Mg and grey-black beta-Mg_(17)Al_(12)phases.With the increase of isothermal temperature,the dendrites of alpha-Mg gradually transform into spherulites,the roundness increases and the grain size decreases,and the microhardness of Mg-6Al-0.9Er alloy increases gradually.With the prolongation of isothermal time,the grain of Mg-6Al-0.9Er alloys gradually turns round,when the isothermal time is 15 min,the complete equiaxed grains are formed,and the microhardness increases gradually.With the increase of compression deformation,the grains tend to be rounded and the microhardness of Mg-6Al-0.9Er alloy increases gradually.The addition of Er can improve the tensile properties and impact toughness of cast Mg-6Al alloy at room temperature.The tensile strength,elongation,section shrinkage and impact toughness of the Mg-6Al-0.9Er alloy increase by 11.3%,32.6%,3.8%and 23.3%respectively after compression deformation of 20%and isothermal heat treatment of 550℃/15 min compared with that of the alloy in cast state.
作者
徐勇
罗峰
XU Yong;LUO Feng(Department of Physical Education,Northern University of Technology,Beijing 100144,China;School of Materials Science and Engineering,Beijing University of Technology,Beijing 100124,China)
出处
《热加工工艺》
北大核心
2021年第20期146-150,154,共6页
Hot Working Technology
