【摘要】 研究了采用热挤压和液态模锻法制备的Al-8.3Zn-3.3Cu-2.2Mg合金的显微组织和力学性能。结果表明：基于DEFORM模拟分析结果，最佳的热挤压工艺参数为铸锭初始温度380℃和挤压速度3 mm/s。T6热处理后的热挤压铝合金表现出优异的力学性能，其屈服强度、抗拉伸强度和延伸率分别为519.6 MPa、582.1 MPa和11.0%。与铸态和液态模锻合金相比，热挤压合金的屈服强度分别提高了30.8%和4.9%，抗拉伸强度分别提高了43.5%和10.2%。热加工合金抗拉伸强度显著提升的原因在于热加工过程消除了组织中的铸造缺陷，细化了基体晶粒组织和共晶组织。此外，热挤压合金相比液态模锻合金表现出更加优异的塑性，这是由于热挤压过程中发生剧烈塑性变形，有效破碎并分散了共晶组织，促进第二相的溶解和沉淀析出，并抑制了微裂纹的萌生。更多还原

【Abstract】 The microstructures and mechanical properties of Al-8.3Zn-3.3Cu-2.2Mg alloys prepared via hot extrusion and liquid forging methods were investigated.Results show that based on DEFORM simulation analysis,the optimal hot extrusion parameters are determined as ingot initial temperature of 380 ℃ and extrusion speed of 3 mm/s.The hot-extruded aluminum alloy after T6 heat treatment presents superior mechanical properties with yield strength of 519.6 MPa,ultimate tensile strength of 582.1 MPa,and elongation of 11.0%.Compared with the properties of gravity-cast and liquid-forged alloys,the yield strength of hot-extruded alloy increases by 30.8% and 4.9%,and the ultimate tensile strength improves by 43.5% and 10.2%,respectively.The significant improvement in tensile strength of the hot-extruded alloys is attributed to the elimination of casting defects and the refinement of matrix grain and eutectic phases.In addition,the hot-extruded alloy demonstrates superior plasticity compared with the liquid-forged alloy.This is because severe plastic deformation occurs during hot extrusion,which effectively breaks and disperses the eutectic phases,facilitating the dissolution and precipitation of the second phases and inhibiting the microcrack initiation.更多还原