3003铝合金的动态拉伸力学性能及断口分析

Dynamic tensile properties and fracture analysis of 3003 aluminum alloy

动态拉伸力学特性是铝合金在汽车轻量化应用中的重要参考指标。通过动态拉伸和数字图像分析技术(DIC)测定了3003铝合金的动态力学性能,利用光学显微镜、场发射扫描电镜、维氏硬度计研究了应变速率对3003铝合金微观组织、硬度的影响。结果表明:随拉伸应变速率增加,伸长率增加,低应力下变形分布均匀;拉伸断裂前的应变集中在样品中部,变形程度和集中度随应变速率增加而增大。断口和显微硬度分析表明,随着应变速率升高,断口中部撕裂棱减少,韧窝直径增大;断口侧表面显微硬度显著提高,晶粒更细长。

Dynamic tensile property of aluminum alloy is an important index for automobile lightweighting design.The dynamic tensile test and digital image analysis(DIC)are used to examine the dynamic tensile properties of 3003 aluminum alloy.The effect of strain rate on microstructure and hardness of 3003 aluminum alloy was investigated by using the optical microscope,the field emission scanning electron microscope,and the Vickers hardness tester.The results show that as the tensile strain rate increases,the elongation increases;the deformation is evenly distributed under low stress,and the plasticity decreases with the increase of the strain rate;the strain before fracture is concentrated in the middle of the sample,and the degree of deformation and concentration are increasing with the increase of strain rate.The analysis on the tensile fracture and microhardness show that with the increase of strain rate,the tearing edge in the middle of the fracture decreases and the dimple diameter increases;at the side of the fracture,the microhardness of the alloy surface increases significantly,and the grains become slender.