(上海交通大學 金屬基復合材料國家重點實驗室，上海 200030)
摘 要: 采用全自動控制往復噴射成形工藝制備了7055鋁合金的大規(guī)格噴射成形錠坯。通過顯微組織分析和力學性能測試，研究工業(yè)規(guī)格噴射成形7055鋁合金的初始組織、擠壓工藝及熱處理制度對顯微組織和力學性能的影響。結(jié)果表明，噴射成形7055鋁合金錠坯規(guī)格可達d 260 mm×1600 mm，晶粒為等軸狀，粒度宏觀均勻，主要在20~30 μm，組織無明顯宏觀偏析，錠坯致密度達到98.2 %。噴射成形態(tài)材料的T6態(tài)σb為500~543 MPa，顯示控制往復噴射成形鋁合金錠坯冶金質(zhì)量優(yōu)越。噴射成形錠坯經(jīng)過小擠壓比變形后達到全致密，大規(guī)格產(chǎn)品的T6態(tài)縱向σb提高到745 MPa，δ為12.8 %。
關(guān)鍵字: 7055鋁合金；噴射成形；熱處理；顯微組織；力學性能
（State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200030,China）
Abstract:A large-scale 7055 Al alloy billet with a size of d 260 mm×1600 mm was prepared by fully automatic controlled reciprocating spray forming technology. The initial microstructure and the effect of subsequent treatment (including extrusion and heat treatment) on the microstructures and mechanical properties of the 7055 alloy were studied. The results show that the as-deposited billet has an equiaxed and homogeneous structure with a grain size of 20−30 μm and no macro-segregation structure. The relative density of the as-deposited alloy gets up to 98.2%. The ultimate tensile strength of as-deposited materials after T6 heat treatment gets up to 500−543 MPa, which indicates that there is little defect in the as-deposited billets produced by fully automatic controlled reciprocating spray forming technology. After deformation at small extrusion ratio, the billets could be fully densified. The ultimate tensile strength of the large-scale materials at T6 state rises to 745 MPa, and the elongation is 12.8%.
Key words: 7055 Al alloy; spray forming; heat treatment; microstructure; mechanical properties
