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由喷射沉积制备Al-12Zn-2.4Mg-1.2Cu(质量分数,%)合金的沉积锭,以不同挤压变形方式制备成Ф100 mm棒材、Ф100 mm×Ф80 mm无缝管材以及160 mm×15 mm的板材。通过光学显微镜、扫描电镜以及力学性能试验研究了不同挤压制品热处理态的组织和力学性能。沉积态合金的显微组织中,晶粒为等轴晶,大小约20μm。在挤压变形过程中,以冶金焊合的方式消除了原先分布在沉积态中晶粒周围的沉积孔隙。不同挤压制品的挤压方向上,金属流线清晰可见。挤压制品的抗拉强度,屈服强度及延伸率测试结果表明:热处理后的棒材横向分别为688 MPa、654 MPa和12%,纵向分别为698 MPa、674 MPa和10.5%;热处理后的板材横截向分别为783 MPa、748 MPa和7%,纵向分别为751 MPa、719 MPa和8%;热处理无缝管材的纵向分别为781 MPa、735 MPa和9%。拉伸断口显示,板材、无缝管材以及挤压板材对应的断口分别呈现出韧性断裂、混合型断裂以及脆性断裂形貌特征。
The deposition ingot of Al-12Zn-2.4Mg-1.2Cu (mass fraction,%) alloy was prepared by spray deposition. The extruded ingot with diameter of 100 mm, Ф100 mm × Ф80 mm and the size of 160 mm × 15 mm plate. The microstructures and mechanical properties of different extruded products were studied by optical microscope, scanning electron microscopy and mechanical properties tests. In the microstructure of the as-deposited alloy, the grains are equiaxed and have a size of about 20 μm. During the extrusion deformation, the deposition pores originally distributed around the grains in the as-deposited state are eliminated by metallurgical welding. Different extruded products in the extrusion direction, the metal streamline is clearly visible. The results of tensile strength, yield strength and elongation of the extruded products showed that the bar after heat treatment was 688 MPa, 654 MPa and 12% respectively, and the longitudinal directions were 698 MPa, 674 MPa and 10.5% respectively. The transverse direction was 783 MPa, 748 MPa and 7% respectively, and the longitudinal directions were 751 MPa, 719 MPa and 8% respectively. The longitudinal directions of heat-treated seamless pipes were 781 MPa, 735 MPa and 9% respectively. Tensile fracture shows that ductile fracture, mixed fracture and brittle fracture topography show the corresponding fracture of sheet, seamless pipe and extruded sheet, respectively.