喷射成形7475铝合金的显微组织与力学性能.pdfVIP

学兔兔 Mar．2010 铸 造 VOI．59 No．3 FOUNDRY ·235· 喷射成形7475~R合金的显微组织与力学性能 朱玉桂，张 豪，张 林，施林波，张 获 (上海交通大学金属基复合材料国家重点实验室，上海200240) 摘要：采用全自动控制往复喷射成形工艺制各了大规格7475铝合金锭坯。研究工业规格喷射成形7475~合金的初始组织、 挤压工艺及热处理制度对显微组织和力学性能的影响。结果表明，喷射成形7475~合金锭坯规格可达 360mmxl 200rtlm， 晶粒为等轴状，粒度宏观均匀，主要在3O～40ixm，组织无明显宏观偏析，锭坯致密度达到97％。喷射成形锭坯经小挤 压比变形后达到全致密，T6态 (480℃x4 h+l35℃×16h)合金性能最优，crh为625～635MPa，6为12％～12．6％，表明控 制住复喷射成形铝合金锭坯冶金质量优越。 关键词：7475铝合金；喷射成形；热处理；显微组织；力学性能 中图分类号：TG146．2 1 文献标识码：A 文章编号：1001—4977(2010)03—0235—04 Microstructure and Mechanical Properties of 7475 Aluminum Alloy by Spray FOrming ZHU Yu—gui，ZHANG Hao，ZHANG Lin，SHI Lin—bo，ZHANG Di (State Key Laboratory of Metal Matrix composites，Shanghai Jiaotong University， Shanghai 200240，China) Abstract：A large—size 7475 aluminum alloy billet of 360 mm×1 200 mm was prepared by fully automatic controlled reciprocating spray forming technology．The as-deposited billet has an equiaxed and homogeneous structure with a grain size of 30—40 um and no macro—segregation．The relative density of the as—deposited alloy gets up to 97％．The initiaI micrOstructure and the e仟ect of subsequent treatment(including extrusion and heat treatment) on the microstructures and mechanicaI properties of the 7475 alloy were studied．The results show that the billets could be fuIly densified after deformation at smal J extrusion ratio and the optimaI mechanicaI properties were obtained after T6 heat treatment。I．e．480℃／4 h+l 35℃ ／1 6 h：the tensile strength gets up to 625—635 MPa and the elongation reaches 1 2％．1 2．6％．This indicates that the qualified as—deposited billets were produced by