摘要
为探究Mg含量对Al-Zn-Mg合金组织和性能的影响,以及冷轧后的时效处理对加工硬化效果的影响,通过直读光谱、扫描电镜、金相显微镜及拉伸试验机等对不同变形+热处理工艺下的Al-6.0Zn-xMg(x=2、3和4)合金铸态及轧制态组织及性能进行分析。结果表明,Mg含量对铸态合金组织形貌、晶粒大小及第二相类型影响不大,非平衡共晶T-AlZnMg相占比随Mg含量的增加而增加,当Mg含量为4%时,共晶相占比减小主要与晶界附近MgZn_(2)弥散相数量增多有关。均质化后经热轧+固溶+冷轧变形热处理后,高熔点Al_(3)Fe相破碎并沿轧制方向分布,显微组织演变过程为,铸态组织→纤维组织→完全再结晶→纤维组织。随着Mg含量的增加,Al-6.0Zn-xMg合金轧板强度逐渐增加,但增幅逐渐减小。冷轧后的时效处理使加工硬化效果降低80~100 MPa,而伸长率提高6%~8%。3种合金中,Al-6.0Zn-4Mg合金的综合性能最佳。
Effect of Mg content on the microstructure and mechanical properties of Al-Zn-Mg alloy and the effect of aging treatment after cold rolling on the strain hardening were studied by analysis of the as-cast and as-rolled microstructure and mechanical properties of Al-6.OZn-xMg(x=2,3,4)alloys undergone different deformation+heat treatments with XRF,SEM,OM and universal tensile testing machine.The results show that the Mg content has only litle effect on the morphology,grain size and second phase type in as-cast state,where the amount of non-equilibrium eutectic phase T-AlZnMg increases with increasing Mg content.When the Mg content is 4%,the amount of eutectic phase decreases,which is related to the increase of MgZn_(2)disperse phase near the grain boundaries.After homogenization treatment,hot rolling and cold rolling processing,the high melting point Al_(3)Fe phase is broken and distributed along the rolling direction.The microstructure transforms as following:as-cast microstructure→fiber microstructure→recrystallized microstructure→fiber microstructure.With the increase of Mg content,the strengths of the as-rolled Al-6.OZn-xMg alloys increase,but the increments decrease.Aging treatment after cold rolling results in an 80-100 MPa decrease of the strength,and 6%-8%increase of the elongation.Among the three alloys,the Al-6.0Zn-4Mg alloy shows the best comprehensive properties.
作者
秦翔智
赵佳蕾
王凯歌
李兵
赵巍
Qin Xiangzhi;Zhao Jialei;Wang Kaige;Li Bing;Zhao Wei(Kunshan Jingwei New Materials Research Institute Co.,Ltd.,Kunshan Jiangsu 215313,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2023年第6期229-236,共8页
Heat Treatment of Metals
