淬火水温及深冷处理对超高强Al-Zn-Mg-Cu合金组织及性能的影响  

Effects of quenching water temperature and cryogenic treatment on microstructure and mechanical properties of ultra⁃high strength Al⁃Zn⁃Mg⁃Cu alloy

作　　者：马志锋 王海龙 赵唯一 付祎磊 陆政 Ma Zhifeng;Wang Hailong;Zhao Weiyi;Fu Yilei;Lu Zheng(Institute of Aluminum Alloy,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;Beijing Engineering Research Center of Advanced Aluminum Alloys and Applications,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China)

机构地区：[1]中国航发北京航空材料研究院铝合金研究所,北京100095 [2]中国航发北京航空材料研究院北京市先进铝合金材料及应用工程技术研究中心,北京100095

出　　处：《金属热处理》2024年第4期195-200,共6页Heat Treatment of Metals

摘　　要：研究了淬火介质(水)温度和深冷处理对Al-Zn-Mg-Cu合金的后续时效微观组织和力学性能的影响。结果表明,Al-Zn-Mg-Cu合金时效前增加深冷处理对强度影响较小,但是可以提升合金的断后伸长率。不同水温淬火影响Al-Zn-Mg-Cu合金的力学性能,室温水淬时合金经固溶+时效后的力学性能最好,抗拉强度为720 MPa,断后伸长率为7.70%,断裂韧度为32.37 MPa·m^(1/2),经固溶+深冷+时效后的塑性提升,断后伸长率增加到8.90%,断裂韧度增加到36.61 MPa·m^(1/2)。深冷处理不改变合金时效过程中析出相的种类,仍然为η′相,但会使η′相数量增加,分布更加均匀弥散,晶界处的析出相间距也增大并呈断续分布的状态。深冷处理能够使合金的断裂韧度更加稳定,降低合金因为淬火水温不同对性能的影响。Effects of the quenching water temperature and cryogenic treatment on the subsequent aged microstructure and mechanical properties of Al⁃Zn⁃Mg⁃Cu alloy were investigated.The results show that the addition of cryogenic treatment before aging has little effect on the strength of the Al⁃Zn⁃Mg⁃Cu alloy,but it can enhance the elongation after fracture.Different water temperatures for quenching affects the mechanical properties of the Al⁃Zn⁃Mg⁃Cu alloy,of which the best mechanical properties after the solution treatment and aging can be achieved by room temperature water quenching,as the tensile strength is 720 MPa,the elongation after fracture is 7.70%and the fracture toughness is 32.37 MPa·m^(1/2).Moreover,after the solution treatment+cryogenic treatment+aging,the elongation after fracture increases to 8.90%and the fracture toughness increases to 36.61 MPa·m^(1/2).The addition of cryogenic treatment does not change the precipitated phase type of the alloy,which is stillη′phase,but it can increase the number ofη′phase and make its distribution more uniform and dispersed,and increase the inter⁃spacing of precipitated phase at the grain boundary and make it distributed discontinuously.The cryogenic treatment can stabilize the fracture toughness of the alloy and reduce the effect of temperature difference of the quenching medium on the mechanical properties of the alloy.

关 键 词：AL-ZN-MG-CU合金 超高强铝合金 淬火水温 深冷处理 应力消除 

分 类 号：TG166.3[金属学及工艺—热处理]