铸造Al-Cu合金中富铁相对拉伸断裂行为的影响

发布时间：2019-01-19 20:51

【摘要】：采用拉伸性能测试、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、深腐蚀、定量金相等技术手段研究了铝铜合金中富铁相对合金力学性能及拉伸断裂行为的影响。结果表明:随着Mn含量的增大,高铁含量合金力学性能得到改善,这主要是由于富铁相的演变和T相的增多以及铸造缺陷减少有关。针状β-Fe是铝铜合金中危害最大的富铁相。在拉伸过程中,针状β-Fe容易引起应力集中,从而导致富铁相与α(Al)基体界面断裂失效。同时针状β-Fe作为裂纹的起源,裂纹将沿着纵向发生二次扩展。与针状β-Fe相比,汉字状的富铁相对性能危害性更小,这是由于裂纹将在汉字状的Al_mFe和α-Fe中的枝晶臂间产生偏转,从而有效阻止裂纹的扩展。与Al_mFe相比,α-Fe比Al_mFe危害更小。这主要是由于Al_mFe具有晶体缺陷,本身能承受拉应力更小,枝晶发达的α-Fe与铝基体的结合力更大,同时发达的枝晶臂可以更加有效抑制裂纹的扩展。
[Abstract]:The effects of Fe-rich alloy on mechanical properties and tensile fracture behavior of Al-Cu alloy were studied by means of tensile test, scanning electron microscope (SEM), (SEM), transmission electron microscope (TEM), deep corrosion and quantitative metallography. The results show that with the increase of Mn content, the mechanical properties of high iron alloy are improved, which is mainly due to the evolution of rich iron phase and the increase of T phase and the decrease of casting defects. Acicular 尾-Fe is the most harmful rich iron phase in Al-Cu alloy. During the tensile process, acicular 尾-Fe easily leads to stress concentration, which leads to the fracture failure of the interface between Fe rich phase and 伪 (Al) matrix. At the same time, the acicular 尾-Fe is the origin of the crack, and the crack will propagate twice along the longitudinal direction. Compared with acicular 尾-Fe, the iron rich in Chinese character is less harmful to the relative performance, because the crack will deflect between the dendrite arm in the Chinese character Al_mFe and 伪-Fe, thus effectively preventing the crack from spreading. Compared with Al_mFe, 伪-Fe is less harmful than Al_mFe. This is mainly due to the fact that Al_mFe has crystal defects and can withstand less tensile stress, and that the dendritic 伪-Fe has stronger adhesion to aluminum matrix, and that the developed dendritic arm can restrain the crack propagation more effectively.
【作者单位】：华南理工大学机械与汽车工程学院;贵州大学机械工程学院;
【基金】：国家自然科学基金项目(51374110) 广东省自然科学基金团队项目(2005A030312003) 贵州大学引进人才科研基金项目(201440) 国家金属材料近净成形工程技术研究中心开放基金项目(2015009)资助
【分类号】：TG146.21

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