挤压比对Al-Zn-Mg-Cu合金微观结构和力学性能的影响  

Effect of extrusion ratio on the microstructure and mechanical properties of Al-Zn-Mg-Cu alloy

作　　者：高文林 王瑞珏 王继成 孙锋 Gao Wenlin;Wang Ruijue;Wang Jicheng;Sun Feng(AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;Hexing Aeronautical Materials(Tianjin)Technology Co.,Ltd.,Tianjin 300399,China;Beijing Engineering Research Center of Advanced Aluminum Alloys and Applications,Beijing 100095,China;Advanced Aluminum Alloy Technology Innovation Center,Beijing 100095,China)

机构地区：[1]中国航发北京航空材料研究院,北京100095 [2]核兴航材(天津)科技有限公司,天津300399 [3]北京市先进铝合金材料及应用工程技术研究中心,北京100095 [4]先进铝合金技术创新中心,北京100095

出　　处：《轻金属》2024年第12期30-36,共7页Light Metals

摘　　要：本研究系统探讨了挤压比对Al-Zn-Mg-Cu合金微观组织及力学性能的影响规律。实验采用不同挤压比的合金样品,通过综合运用光学显微镜、扫描电镜、电子背散射衍射和透射电镜等先进技术手段,结合拉伸试验,深入分析了挤压比对合金晶粒尺寸、织构分布以及力学性能的影响。实验结果表明,随着挤压比的增加,合金晶粒尺寸略有增大,抗拉强度略有下降,而屈服强度则显著提升,同时伸长率有所下降。这主要是由于较大的挤压比提供了足够的驱动力以克服第二相的钉扎作用,促进了亚结构向再结晶晶粒的快速转变,从而提高了合金的抗拉强度。然而,过大的变形量也加速了高温条件下的回复和再结晶过程,导致晶粒尺寸的增大和伸长率的降低。此外,研究还发现,随着挤压比的增加,合金的织构取向逐渐由<111>向<001>转变,且晶界处纳米尺寸的MgZn 2粒子对位错堆积和DRX过程具有重要影响。这些研究结果为优化Al-Zn-Mg-Cu合金的挤压工艺和提高其综合性能提供了重要的理论依据。This study systematically explored the influence of extrusion ratio on the microstructure and mechanical properties of Al-Zn-Mg-Cu alloy.The experimental samples with different extrusion ratios were used,and advanced techniques such as optical microscopy,scanning electron microscopy,electron backscatter diffraction and transmission electron microscopy were comprehensively applied in combination with tensile tests to deeply analyze the influence of extrusion ratio on the grain size,texture distribution and mechanical properties of the alloy.The experimental results show that with the increase of extrusion ratio,the grain size of the alloy slightly increases,the tensile strength slightly decreases,while the yield strength significantly increases,and the elongation rate slightly decreases.This was mainly due to the large extrusion ratio providing sufficient driving force to overcome the pinning effect of second phases,promoting the rapid transformation of substructures into recrystallized grains,thereby improving the tensile strength of the alloy.However,excessive deformation also accelerated the recovery and recrystallization processes under high temperature conditions,resulting in an increase in grain size and a decrease in elongation.In addition,it was found that with the increase of extrusion ratio,the texture orientation of the alloy gradually shifted from<111>to<001>,and the nanometer-sized MgZn 2 particles at the grain boundary had an important influence on dislocation accumulation and DRX processes.These research results provide important theoretical basis for optimizing the extrusion process and improving the comprehensive performance of Al-Zn-Mg-Cu alloy.

关 键 词：AL-ZN-MG-CU合金 挤压比 力学性能 微观结构 

分 类 号：TF125.22[冶金工程—粉末冶金]