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采用全自动控制往复喷射成形工艺制备了Ф360 mm×1200 mm工业规格7475铝合金喷射成形坯。采用常规力学性能和电导率测试,应用光学显微镜、扫描电镜和透射电镜观察微观组织,研究了沉积态、挤压态和热处理状态下喷射成形7475铝合金组织和性能的演变。结果表明,沉积态组织为等轴晶,粒度宏观均匀,晶粒尺寸在30~40μm,无明显宏观偏析,致密度达97%,强度比传统铸造合金提高63.6%;热挤压后,孔隙基本消除,比传统铸造合金强度提高45.5%,伸长率提高25.3%。T6处理后,强度为738 MPa,电导率为39.4%IACS,比传统铸造合金强度提高33.0%,电导率提高9.4%;双级时效降低合金强度,提高电导率;回归再时效处理后,强度为716 MPa,电导率达43.3%IACS,能使合金获得优异的综合性能。
The Ф360 mm × 1200 mm industry standard 7475 aluminum alloy spray blank was prepared by automatic control of reciprocating spray forming process. The microstructure was observed by optical microscope, scanning electron microscopy and transmission electron microscopy. The microstructures and properties of spray-formed 7475 aluminum alloy were investigated under the condition of as-deposited, extruded and heat-treated. The results show that the microstructure is equiaxed and the grain size is 30 ~ 40μm with no macroscopic segregation, the density is up to 97% and the strength is 63.6% higher than that of the traditional cast alloy. After hot extrusion, Elimination, than the traditional cast alloy strength increased 45.5%, elongation increased 25.3%. T6 treatment, the strength of 738 MPa, the conductivity of 39.4% IACS, than the traditional cast alloy strength increased by 33.0%, the conductivity increased by 9.4%; two-stage aging reduce the alloy strength, improve the conductivity; re-aging treatment, the intensity 716 MPa, conductivity of 43.3% IACS, the alloy can obtain excellent overall performance.