Sn-Zn-Bi-Ga掺杂Ti纳米颗粒钎料制备及钎焊性能

为解决Sn-Zn系无铅钎料性能难以满足电子封装实际应用的问题,采用Ti纳米颗粒掺杂的方法制备了Sn-5Zn-10Bi-0.5Ga+x Ti无铅钎料(x为质量分数,分别取0.05%、0.1%、0.3%、0.5%),研究了Ti纳米颗粒对钎料的润湿性能、抗氧化性能的影响,对钎焊的钎焊接头界面处的组织结构、金属间化合物扩散层厚度特征,以及力学性能等影响。研究结果表明:Ti纳米颗粒的添加能提高钎料的润湿性能和抗氧化性能,还能改善界面处的组织结构和力学性能。当添加Ti纳米颗粒质量分数为0.3%时,钎料抗氧化性能最好,其氧化增重质量比最先趋于稳定且增长率最低,其焊件的剪切强度为32.10 MPa,达到最大值。

Effect of postweld heat treatment on interface microstructure and metallurgical properties of explosively welded bronze–carbon steel

The effects of postweld heat treatment on the microstructure and metallurgical properties of a bronze–carbon steel(st37)explosively bonded interface were studied.Explosive welding was done under 1.5-and 2-mm standoff distances and different conditions of explosive charge.Samples were postweld heat treated for 4 and 16 h in the furnace at 250°C and 500°C and then air cooled.Laboratory studies using optical microscopy,scanning electron microscopy,and microhardness testing were used to evaluate the welded samples.Microstructural examinations showed that by increasing the standoff distance and the explosive charge,the interface of bronze to steel became wavier.The microhardness test result showed that the hardness of the samples was higher near the joint interface compared with other areas because of the intensive plastic deformation,which was caused by the explosion force.The results show that increasing the heat treatment temperature and time caused the intermetallic compounds’layer thickness to increase,and,because of the higher diffusion of copper and tin,the iron amount in the intermetallic compounds decreased.Also,because of the increase in heat treatment temperature and time,internal stresses were released,and the interface hardness decreased.