微观组织特征对服役6N01-T6铝合金材料力学性能的影响  

Influence of microstructure characteristics on the mechanical properties of 6N01-T6 aluminum alloy materials in service

作　　者：田洪雷 吴广宇 王天 王富杰 郄默繁 何长树 Tian Honglei;Wu Guangyu;Wang Tian;Wang Fujie;Qie Mofan;He Changshu(R&D Center,CRRC Qingdao Sifang Co.,Ltd.,Qingdao 266111,China;School of Materials Science and Engineering,Northeastern University,Shenyang 110819,China;Key Laboratory for Anisotropy and Texture of Materials,Northeastern University,Shenyang 110819,China)

机构地区：[1]中车青岛四方机车车辆股份有限公司技术中心,山东青岛266111 [2]东北大学材料科学与工程学院,辽宁沈阳110819 [3]东北大学材料各向异性与织构教育部重点实验室,辽宁沈阳110819

出　　处：《轻金属》2022年第4期49-54,共6页Light Metals

摘　　要：为了掌握车体结构材料长期服役后性能的变化规律以及综合评估服役车体的可靠性,本研究对两种服役不同里程的6N01-T6铝合金车体侧墙型材(型材A和型材B)进行取样,测试了拉伸性能和疲劳性能,并结合微观组织表征结果,分析讨论了微观组织特征对长期服役铝合金侧墙型材力学性能的影响。结果表明,型材A横断面微观组织为均匀粗大等轴状晶,针状析出相粒子长度约为60 nm;型材B横断面的表层为粗大等轴晶,心部为细长纤维状晶,针状析出相粒子长度约为35 nm。型材A拉伸试样的平均屈服强度、抗拉强度和延伸率分别为254 MPa、277 MPa和7.8%;型材B拉伸试样的平均屈服强度、抗拉强度和延伸率分别为247 MPa、282 MPa和11.2%。在可靠度为97.5%、置信度为95%的条件下,型材A和型材B的疲劳极限分别为81.6 MPa和101.7 MPa,微观组织特征差异是导致长期服役后两种型材延伸率和疲劳性能存在明显差异的主要原因。In order to grasp the changes of the properties of the vehicle body structure materials after long-term service and to comprehensively evaluate the reliability of the vehicle body in service, this study sampled two 6 N01-T6 aluminum alloy body sidewall profiles(profile A and profile B) with different mileage in service, tested the tensile and fatigue properties, analyzed and discussed the influence of microstructure characteristics on the long-term service aluminum alloy sidewall profiles in combination with the results of microstructure characterization. The results showed that the microstructure of profile A cross-section was uniform coarse equiaxed crystals, and the length of needle-like precipitation phase particles was about 60 nm;The surface layer of profile B cross-section was coarse equiaxed crystals, and the core was slender fibrous crystals, and the length of needle-like precipitation phase particles was about 35 nm. The average yield strength, tensile strength and elongation of profile A tensile samples were 254 MPa, 277 MPa and 7.8%, respectively;The average yield strength, tensile strength and elongation of profile B tensile samples were 247 MPa, 282 MPa and 11.2%, respectively. The fatigue limits of profile A and profile B were 81.6 MPa and 101.7 MPa, respectively, under the conditions of 97.5% reliability and 95% confidence. The differences in microstructure characteristics were the main reasons for the significant differences in elongation and fatigue properties of the two profiles after long-term service.

关 键 词：6N01-T6铝合金 挤压材 服役性能 显微组织 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]