钨铜/铍青铜异质钎焊界面组织与性能

Microstructure and properties of brazed W-Cu composites and beryllium bronze joint

采用BAg56CuZnSn,BAg50ZnCdCuNi和BAg49ZnCuMnNi银钎料实施了钨铜合金/铍青铜异质材料接头的感应钎焊连接,研究了其钎焊界面组织与力学性能.结果表明,3种银钎料均能获得完好界面钎焊接头,钎料与钨铜和铍青铜形成较好冶金结合.钎料与铍青铜界面冶金结合充分,形成明显互扩散区.钎料与钨铜钎焊界面清晰,且钎料向钨铜近界面区域形成明显扩散渗入现象.强度测试表明,BAg49ZnCuMnNi钎焊接头强度最高,达到250 MPa,接头断裂均发生在钨铜侧钎焊界面.分析表明,钎料向钨铜渗入明显促进界面结合,钎料中添加镍,由于镍与钨的扩散互溶进一步提高界面冶金结合,Mn元素添加明显细化钎缝晶粒,接头强度显著提升.

W-Cu composites and Beryllium bronze dissimilar joints were prepared by induction brazing method using BAg56CuZnSn,BAg50ZnCdCuNi and BAg49ZnCuNi Mn,respectively.Interfacial microstructure and mechanical properties of the brazed joints were studied.The results show that all the brazed joints displayed perfectly metallurgical bonded interface.Obvious diffusion zone was formed in bonded interface between braze and beryllium bronze.The fracture of brazed joints all occurred at the brazing interface of W-Cu side,and the joint using BAg49ZnCuNiMn solder obtained the highest strength which reaching 250 MPa.Meanwhile,clear boundary braze/W-Cu interface was also observed.The braze had obviously infiltrated into the W-Cu matrix near their interface,leading to increasing of the interface bonding strength.The addition of nickel in braze further improved the metallurgical bonding of the interface due to the diffusion and mutual dissolution of nickel and tungsten.Furthermore,manganese can refine the grain size of brazed joint and improve the joint strength.