CuNiCrSi铜合金搅拌摩擦焊工艺参数与组织性能分析

Analysis of parameters and properties of nickel-chromiumsilicon-copper friction stir welding

为了探究CuNiCrSi铜合金搅拌摩擦焊工艺参数与组织性能,采用正交试验法对工艺参数进行优化,并研究了焊缝的组织性能及材料流动性.结果表明,焊接速度是对焊接过程影响最为显著的因素,试验得到焊接最佳工艺参数组合,在最优参数组合下焊缝的抗拉强度为491.4 MPa,达到母材抗拉强度的84.7%.当焊接速度过大时会在焊缝的前进侧出现隧道型缺陷;材料的流动可以分为四部分;前进侧材料流动情况比返回侧复杂;焊接速度过小时表面会出现毛刺;母材区粗大的粒子为铬和硅的偏聚物,而镍无偏聚均匀地分布在材料中;焊核区晶粒随着焊接速度的增加而变小.最优参数下焊核区晶粒虽然细小均匀,但硬度却比母材区低.

In order to investigate the process parameters and properties of CuNiCrSi copper alloy jointed by friction stir welding, the orthogonal experimental method was used to optimize the process parameters, and the properties and material flow were studied. The results show that the welding speed is the most significant factor affecting the welding process. The experiment has got the best combination of process parameters, and the tensile strength of the weld was491.4 MPa, which was 84.7% of the tensile strength of the base metal under these optimum welding parameters.When the welding speed is too large, there will be tunnel defects on the advancing side of the weld, and the flow of the forward material is more complicated than that of the retreating side.When the welding speed is too small, the surface will havefin.The coarse particles in the parent material area are segnagations of chromium and silicon, and the nickel is uniformly distributed in the material. The grains in the nuggest zone become smaller as the welding speed increases. Under the optimal parameters, the grain size of the nuggest zone is small and uniform, but the hardness is lower than that of the base metal. The fracture method is ductile fracture, which indicates that the material has good toughness.