| 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. |
| 关键词: 毛化 硬质合金 铝 预涂覆 扩散连接 |
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| 基金项目: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) |
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| Vacuum diffusion bonding of textured WC-Co cemented carbide and aluminum |
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ZHANG Lixia, ZHANG Ruoheng, YANG Jinghong, LEI Min
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State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China
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| Abstract: |
| 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/Al3Ni+Al3Ni2+Al5Co2/Co-Ni(s.s)/W-Co-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 Al3Ni+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 51MPa, 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. |
| Key words: texturing WC-Co cemented carbide aluminum precoating diffusion bonding |
