6016铝合金板材微观组织及力学性能的试验研究

Experimental study on microstructure and mechanical properties of 6016 aluminum alloy sheet

采用金相显微镜(OM)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和拉伸试验等分析检测方法,研究了6016铝合金板材和冷冲压成形后的汽车B柱零件的微观组织和力学性能。结果表明:在0°,45°和90°方向上,汽车B柱侧壁的伸长率和应变硬化指数n与原材料相比有显著降低,在冲压成形过程中产生了加工硬化,其塑性和应变硬化效果降低;汽车B柱侧壁沿垂直方向的大变形使各向异性明显增加;汽车B柱大变形区有大量的位错累积,产生位错缠结现象,位错密度显著高于未变形区。6016铝合金板材在冲压成形后第二相粒子尺寸减小,弥散强化的作用明显,力学性能发生变化。

Microstructures and mechanical properties of 6016 aluminum alloy sheet and automobile B column parts after cold stamping were investigated by optical microscope(OM),scanning electron microscopy(SEM),transmission electron microscopy(TEM),tensile test and other analytical methods.The results show that the elongation and strain hardening index n of side wall of automotive B column in 0°,45°and 90°directions are significantly lower than that of the initial material,which has work-hardening during the stamping process,and the plasticity and the strain hardening effect are reduced.The anisotropy increases significantly caused by the large deformation of side wall of automotive B column in the vertical direction.The large deformation zone of automotive B column has a large number of dislocation accumulation and dislocation tangle,and the dislocation density is significantly higher than that of the undeformed zone.After stamping of 6016 aluminum alloy sheet,the size of the second phase particles decreases,the effect of dispersion strengthening is notable,and the mechanical properties are changed.