Microstructural evolution and mechanical properties of an ultrahighstrength Al-Zn-Mg-Cu alloy via powder metallurgy and hot extrusion

粉末冶金-热挤压制备超高强度Al-Zn-Mg-Cu合金的组织及力学性能

In this work,a novel ultrahigh-strength Al-10Zn-3.5Mg-1.5Cu alloy was fabricated by powder metallurgy followed by hot extrusion.Investigations on microstructural evolution and mechanical properties of the fabricated samples were carried out.The results show that the grain size of sintered samples matches with the powder particles after ball milling.The relative densities of sintered and hot extruded samples reach 99.1%and 100%,respectively.Owing to the comprehensive mechanism of grain refinement,aging and dispersion strengthening,the ultimate tensile strength,yield strength and elongation of the Al-10Zn-3.5Mg-1.5Cu alloy after hot extrusion and subsequent heat treatment achieve 810 MPa,770 MPa and 8%,respectively.

本文采用粉末冶金联合热挤压工艺制备了一种新型超高强度Al-10Zn-3.5Mg-1.5Cu合金,并对其组织演变和力学性能进行了研究。结果表明:烧结样品的晶粒尺寸与球磨粉末颗粒的尺寸相一致。烧结和热挤压样品的相对密度分别达到99.1%和100%。通过晶粒细化、时效强化和弥散强化的综合作用机制,Al-10Zn-3.5Mg-1.5Cu合金经热挤压和热处理后,极限抗拉强度达到810 MPa,屈服强度达到770 MPa,断后伸长率达到8%。