摘要
对84mm轨道客车用6082-T6铝合金搅拌摩擦焊接头疲劳性能以及断口特征进行试验研究。结果表明,搅拌摩擦焊接头疲劳循环次数随施加载荷减小而增加,当N=107时,疲劳极限值为110MPa,且疲劳断裂主要发生在前进侧热机械影响区。在预制缺口、相同载荷应力条件下,焊核区疲劳循环次数达7.4万次,断口表现为沿晶断裂,裂纹由疲劳源向四周扩展,晶粒细化提高了焊核区疲劳寿命;而前进侧热机械影响区疲劳循环次数最少为2.5万次,裂纹沿晶界向焊核区方向扩展,扩展方式为沿晶和穿晶混合断裂,晶粒发生弯曲变形以及第二相粒子剥离是接头ATMAZ疲劳性能下降的主要原因。
The fatigue performance and fracture characteristics of 84 mm thickness 6082-T6 Al alloy used in railway vehicles were studied that produced by friction stir welding.The results indicate that the number of fatigue cycles increases with the decrease of the load.For N =107,the stress value is100 MPa,and the fatigue fracture mainly occurs in ATMAZ.With prefabricated gap and the same load stress,the fatigue cycle of the WNZ is 740 thousand times.The fracture is presented as intergranular,and the crack extends outward from the fatigue source.The refined grain increases the fatigue life of the WNZ.The fatigue cycle of the ATMAZ is over 25 thousand times,and the crack is along the grainboundariesto WNZ.The fracturing way can be pictured as inter-granular and trans-granular combined fracture.Grain bending deformation and second phase particle detachment are the main reasons of ATMAZ joint fatigue performance deterioration.
出处
《长春工业大学学报》
CAS
2017年第5期496-500,共5页
Journal of Changchun University of Technology
基金
长春市科技创新"双十工程"基金资助项目(17SS024)
