叠片粉末冶金制备超细晶Al-4%Cu合金的组织与性能

Microstructure and properties of ultra-fined Al-4%Cu alloy via flake powder metallurgy

以纯铝、铜粉末为起始原料,采用叠片粉末冶金技术路线,通过球磨片化、复合造粒与扩散合金化,制备出了高强塑性匹配的超细晶Al-4%Cu合金。利用XRD、SEM及TEM,表征了合金相形成、演变及微观组织,并与采用球形铝粉的传统粉末冶金技术制备的Al-4%Cu合金进行了性能对比。结果表明,叠片粉末冶金能够获得拉长超细晶组织,引入的Al2O3纳米相使拉长晶在热变形加工过程得以保留;叠片粉末冶金所制备的Al-4%Cu合金屈服强度为378MPa、抗拉强度达到527MPa,分别比传统粉末冶金提高26.4%和19.2%,同时保持14.2%的延伸率,实现了强度和塑性的均衡匹配,为高强韧大块铝合金材料制备提供了新思路。

In this work,ultrafine-grained Al-4%Cu alloy with balanced strength and ductility has been fabricated using Al and Cu powders via flake powder metallurgy,which included ball-milling of spherical powders to flake powders,balling of mixing flake powders to composite particles,and annealing diffusion alloying.Phase and microstructure evolution during the preparing process of ultra-fined alloys were characterized by XRD,SEM and TEM,and the mechanical property has been compared with traditional powder metallurgy with spherical Al powders.Results indicate that flake powder metallurgy could achieve the elongated ultrafine-grained structures,and the elongated structure could be retained due to nano-Al2O3 introduced by flake powders.The final Al-4%Cu alloy via flake powder metallurgy had high strength up to 378 MPa and 527 MPa for the yield and ultimate strength,respectively.Meanwhile,a high tensile ductility up to 14.2% could be obtained.The flake powder metallurgy could be used for other alloys with balanced strength and ductility.