摘要
采用机械方法对WC-Co硬质合金表面进行焊前毛化加工,然后采用BNi2钎料对毛化后的硬质合金表面进行预涂覆处理,最终利用毛化凸台在铝中的压入及界面元素的扩散反应实现WC-Co硬质合金与铝的真空扩散连接.结果表明,接头界面结构为:Al/Al3Ni+Al3Ni2+Al5Co2/Co-Ni(s.s)/W-Co-Ni/WC-Co.随着预涂覆温度的升高,W-Co-Ni化合物相的体积增大,界面由平齐向不规则演变;随着扩散温度的提高,Al3Ni+Al3Ni2+Al5Co2层厚度增加.当工艺参数增加时,接头抗剪强度呈现出先升高后降低的变化趋势,特别是当预涂覆温度为1 050℃,扩散连接温度为575℃,保温时间为90 min时,接头室温抗剪强度达到最大值51 MPa,明显高于未毛化接头的抗剪强度.
The surface of WC-Co hard metal was mechanically textured and then precoated using BNi2 brazing filler metal,then the WC-Co / Al joint was prepared by vacuum diffusion bonding. The results indicated that the microstructure of the interface is aluminum / Al3 Ni + Al3Ni2+ Al5Co2/ Co-Ni( s. s) / WCo-Ni / WC-Co. With the increasing of the precoating temperature,the volume of layer of W-Co-Ni compound increased and the morphology of the interface of WC-Co / BNi2 transformed from flat to irregular. With the increasing of diffusion bonding temperature,the thickness of Al3 Ni + Al3Ni2+ Al5Co2 layer increased.It was found that when the bonding parameters increased,the shear strength of the joints increased in the first stage and then decreased. The maximum shear strength of WC-Co / BNi2 / Al joints was 51 MPa,with a precoating temperature of 1 050 ℃,diffusion bonding temperature of 575 ℃ with holding time of 90 minutes,which largely exceeded the shear strength of the joints without surface texturing pretreatment.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2016年第1期95-98,133,共4页
Transactions of The China Welding Institution
基金
教育部新世纪优秀人才资助项目(NCET-12-0155)
哈尔滨工业大学科研创新基金资助项目(HIT.NSRIF.2010115)
关键词
毛化
硬质合金
铝
预涂覆
扩散连接
texturing
WC-Co cemented carbide
aluminum
precoating
diffusion bonding
