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采用热轧+半固态热处理+热轧的工艺制备出7075铝合金半固态板材,并对该板材进行了显微组织观察与力学性能测试。结果表明:7075铝合金半固态坯料热轧后,显微组织的α-Al固相颗粒沿RD(轧向)与TD(板宽向)方向拉长,而“液相”则变化不明显。半固态坯料热轧时,α-Al固相颗粒有较好的塑性变形能力,“液相”的塑性变形能力较差。最终得到的半固态板材力学性能为:屈服强度125 MPa,抗拉强度256 MPa,弹性模量6250 MPa,伸长率5.3%。拉伸断裂类型为准解理断裂,断口存在少量二次裂纹和孔洞,韧窝底部存在引起裂纹源的夹杂物或第二相粒子。
7075 aluminum alloy semi-solid plate was prepared by hot rolling + semi-solid heat treatment + hot rolling. The microstructure and mechanical properties of the plate were tested. The results show that the microstructure of α-Al solid particles of 7075 aluminum alloy after hot rolling is elongated along RD (rolling direction) and TD (plate width direction), and the “liquid phase” does not change obvious. Semi-solid billet hot-rolled, α-Al solid particles have better plastic deformation capacity, “liquid ” plastic deformation is poor. The mechanical properties of the resulting semi-solid plate are as follows: yield strength 125 MPa, tensile strength 256 MPa, elastic modulus 6250 MPa and elongation 5.3%. Tensile fracture type quasi-cleavage fracture, there are a small number of secondary fracture cracks and holes, dimples at the bottom of the source of inclusions or second phase particles.