【作者】 王资兴； 张永安； 何小青； 朱宝宏； 刘红伟； 王锋； 熊柏青； 谢建新；

【Author】 WANG Zi-xing, ZHANG Yong-an, HE Xiao-qing, ZHU Bao-hong, LIU Hong-wei, WANG Feng, XIONG Bai-qing, XIE jian-xin (School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China; State Key Laboratory for Fabrication and Processing of Nonferrous Metals, General Research Institute for Nonferrous Metals, Beijing 100088, China)

【机构】 北京科技大学材料科学与工程学院； 北京有色金属研究总院有色金属材料制备加工国家重点实验室；

【摘要】 在研究喷射成形Al10.8Zn2.9Mg1.9Cu超高强铝合金的室温拉伸力学性能的基础上,进一步研究了该合金在不同应力集中系数下的高周疲劳极限;并对疲劳断口和相关显微组织进行了分析;对疲劳机理进行了探讨。结果表明:在双级时效条件下,喷射成形Al10.8Zn2.9Mg1.9Cu超高强铝合金的抗拉强度可达730-740 MPa,延伸率可达8%-10%;该合金在应力比为0.1、应力集中系数为1、指定寿命为1×107循环的情况下,疲劳极限可达400 MPa以上;在应力集中系数提高到3时,疲劳极限高于120 MPa;疲劳裂纹源容易萌生在试样周边部位上粗大的第二相处、材料中的微观组织缺陷处以及试样表面机加工缺陷处。更多还原

【Abstract】 Based on the research of the tensile properties of spray forming ultra-strength Al10. 8Zn2. 9Mg1. 9Cu aluminumalloys, the high-cycle fatigue life at different theoretical stress concentration factors was investigated, the fatigue fracture surface and microstructure were observed and analyzed, and the fatigue mechanism was discussed. The results indicate that the tensile strength of spray formed Al10. 8Zn2. 9Mg1. 9Cu alloys can reach up to 730 - 740 MPa, and elongation reaches 8%-10% in the condition of two-stage ageing. At the stress ratio of 0. 1, the maximum stress for 1×107 cycles is over 400 and 120 MPa when the theoretical stress concentration is 1 and 3, respectively. The fatigue cracking initiations are inclined to begin at the second phases, the microstructure defects and the machining exterior defects.更多还原