自制焊丝与商品焊丝对激光焊件机械性能的影响

The effects of different welding wires on the mechanical properties of laser welding joints

目的:通过宏观及微观分析焊丝对焊件机械强度的影响,为临床选择焊丝提供依据。方法:采用不同焊丝(自制和商业成品焊丝)对钴铬合金、镍铬合金进行焊接,测定焊件的最大抗拉及抗弯强度,对数据进行单因素方差分析;并通过微观断口扫描电镜观察和熔合区金相分析,探讨焊丝对焊件机械强度的影响。结果:钴铬合金自制焊丝组和商品焊丝组的最大抗拉强度分别为(606.40±82.53)MPa和(693.61±47.68)MPa,最大抗弯强度分别为(997.95±88.89)MPa和(1160.76±91.59)MPa,2组焊件的最大抗拉及抗弯强度均有显著差异(P<0.05);镍铬合金自制焊丝组和商品焊丝组的最大抗拉强度分别为(558.14±46.75)MPa和(582.32±35.43)MPa,最大抗弯强度分别为(1084.75±46.02)MPa和(1078.29±36.25)MPa,2组焊件的最大抗拉及抗弯强度均无显著差异(P>0.05)。断口扫描电镜及熔合区金相分析显示:自制焊丝组焊件的裂纹明显多于商品焊丝组。结论:对力学性能要求较高部位的焊接,应采用商业焊丝。

PURPOSE： To evaluate the mechanical properties and microstructure of laser-welded joints with different welding wires for clinical use of welding wire. METHODS： The standard tensile test and three-point bending test rods were made from Co-Cr and Ni-Cr alloy,and were laser-welded with different welding wire （commercially welding wire and casting wire）. Then the tensile rods were tested for the ultimate tensile strength （UTS）, and the bending rods for the ultimate bending strength （UBS）. The results was analyzed by one-way ANOVA. The tensile fracture surface were examined by scanning electron microscopy （SEM）. Metallurgical analysis were also performed on polished longitudinal sectioned samples. RESULTS： For Co-Cr alloy, the UTS of casting wire group and commercially welding wire group was respectively （606.40±82.53）MPa and （693.61±47.68）MPa; the UBS was respectively （997.95±88.89）MPa and （1160.76± 91.59）MPa. ANOVA showed a significant difference of UTS and UBS between the two groups at the 0.05 level （P〈0.05）. For Ni-Cr alloy, the UTS of casting wire group and commercially welding wire group was respectively （558.14±46.75）MPa and （582.32±35.43）MPa; the UBS was respectively （1084.75±46.02）MPa and （1078.29±36.25）MPa. There was no significant difference between the two groups （P〉0.05）. SEM and metallurgical examination showed the welded zone exhibiting more cracks in the casting wire group than in the commercially welding wire group. CONCLUSION： It would be advisable to work with commercially welding wire for the joints that need better strength. Supported by Shanghai Leading Academic Discipline Project （Grant No.T0202）.