超大预拉伸变形对6061铝合金板材组织和性能的影响

Effect of Super Large Pre-Stretching Deformation on Microstructure and Properties of 6061 Aluminum Alloy Sheets

采用室温拉伸、电导率测量等实验研究预拉伸变形对6061铝合金板材力学性能及组织的影响,结合金相显微镜(OM)与扫描电镜(SEM)分析和探讨其影响机理。结果表明,随预拉伸变形量的增加,板材厚度不断减小,富铁相破碎分布于晶界间,纵向晶粒平均截距从36.72μm降至32.99μm;当预拉伸变形量为4%时,可在不降低其力学性能情况下改善板材表面质量;当预拉伸变形量为16%时,经170℃/12h人工时效可使其力学性能达到峰值,此时抗拉强度、屈服强度与延伸率分别为359.76MPa、346.73MPa与12.74%。

In this paper,the effects of pre-stretching deformation on the mechanical properties and structure of 6061 aluminum alloy sheets are studied by room temperature tensile and electrical conductivity measurement experiments,and the mechanism of the influence is analyzed and discussed by combining optical microscope(OM)and scanning electron microscope(SEM).The results showed that with the increase of the pre-stretching deformation,the thickness of the sheets continue to decrease,the iron-rich phases are broken and distributed between the grain boundaries,and the average intercept of the longitudinal grains decrease from 36.72μm to 32.99μm;when the pre-stretching deformation is 4%,the surface quality of the sheets could be improved without reducing its mechanical properties;when the pre-stretching deformation is 16%,the mechanical properties could reach the peak after 170℃/12h artificial aging,with a tensile strength,yield strength and elongation of 359.76MPa,346.73MPa and 12.74%respectively.