单向拉伸时不同变形量对Zn-0.05Mg合金组织的影响

Study on microstructure and mechanical properties of extruded Zn-0. 05Mg alloy

本文利用电子背散射衍射技术和室温拉伸试验,研究了挤压态Zn-0.05Mg二元合金保持应变速率10^(-3)s^(-1),在不同应变阶段时的显微组织特征。结果发现,相比挤压态合金,随着变形量增加,基体平均晶粒尺寸先增大后减小,即由挤压态的1.25±0.6μm,增加至变形量5%时的1.80±0.5μm,而当变形量增加至10%时,又减小至0.93±0.5μm,但晶粒尺寸的分布更加均匀;小角度晶界的比例却减少,但增加变形量后又有所增加。合金织构由挤压态ED//<0110>晶向的丝织构向TD与<0001>形成约75°左右夹角的非基面织构发生转变。二次加载的抗拉强度低于挤压态锌合金的抗拉强度,意味着发生了加工软化。

In this paper,the microstructure characteristics of as-extruded Zn-0.05Mg binary alloy at different strain stages at a strain rate of 10^(-3)s^(-1)were studied by electron backscatter diffraction technique and room temperature tensile test.The results show that,compared with the as-extruded alloy,with the increase of deformation,the average grain size of the matrix first increases and then decreases,that is,from 1.25±0.6μm in the as-extruded state to 1.80±0.6μm when the deformation amount is 5%.0.5μm,and when the deformation increased to 10%,it decreased to 0.93±0.5μm,but the grain size distribution was more uniform;the proportion of small-angle grain boundaries decreased,but increased after increasing the deformation.The texture of the alloy transformed from the silk texture in the extruded ED//<0110>crystal orientation to the non-basal texture in which the TD and<0001>formed an angle of about 75°.The tensile strength of the secondary loading is lower than that of the as-extruded zinc alloy,which implies that work softening has occurred.