摘要
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。
Al-12Zn-2.4Mg-1.2Cu（wt%） alloy billets as-deposited were extruded to be Ф100 mm bar, Ф100 mm×Ф 80 mm seamless pipe and 160 mm×15 mm stripper plate under different deformation ways. The microstructures of the products as-heat-treated were studied by optical metallographic and scanning electron microscope, and the mechanical properties were also measured. Metallographic microstructures show that the grains in the initial billets are almost equiaxed with diameter about 20 μm. There are some second phases precipitated distributing in the grains and on the grain boundary. The deposited ventages around the grains as-deposited were welded together by a welding metallurgy way during extrusion process. The flow lines were clearly observed in the extrusion direction in all different extruded products. For the products as-heat-treated, the tensile strengths, the yield strengths and the elongations of the bars are 688 MPa, 654 MPa and 12% in the cross direction（CD）, while 698 MPa, 674 MPa and 10.5% in the longitude direction（LD）; for the plates they are 783 MPa, 748 MPa and 7% in CD; while 751 MPa, 719 MPa, and 8% in LD; for the pipes they are 781 MPa, 735 MPa and 9% in LD. Scanning electron microscope examination reveals the fracture characteristics of the fractured specimens exhibit three different fracture models which are ductile fracture, mixed fracture and brittle fracture corresponding to bars, pipes and plates, respectively.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2016年第9期2237-2241,共5页
Rare Metal Materials and Engineering
基金
Nature Science Foundation of Ningbo(2014A6100061)
