钎焊工艺对SiC/Kovar真空钎焊接头组织与性能的影响
Influence of Brazing Process on Microstructure and Properties of SiC/Kovar Vacuum Brazed Joint
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摘要: 采用Ag-Cu-Ti/Cu/Ag-Cu软性复合中间层钎料,研究了钎焊温度(810℃-900℃)、保温时间(5 min-30 min)对SiC陶瓷和Kovar合金真空钎焊接头组织及力学性能的影响。结果表明,随着钎焊温度的升高,两侧母材溶解加剧,陶瓷侧界面反应层TiC变厚,焊缝中脆性相Fe3Si、Ni2Si含量增多,不利于残余应力的释放,其接头抗剪强度呈下降趋势。随着保温时间的延长,焊缝微观组织形貌变化不大,陶瓷侧界面反应层厚度先增加后保持不变;Cu(s,s)倾向于聚集在Kovar合金周围,其接头抗剪强度呈先升后降的趋势。当钎焊温度为810℃,保温时间为15 min时,钎焊接头抗剪强度最大,为33 MPa,其接头组织为:SiC陶瓷/TiC/Cu(s,s)+Ag(s,s)/Fe2Ti+Fe3Si/Kovar合金。Abstract: SiC ceramic was brazed to Kovar alloy with Ag-Cu-Ti/Cu/Ag-Cu soft compound interlayer solder.The influence of the brazing temperature(810-900℃)and holding time(5-30 min)on the microstructure and me-chanical properties of the joins were studied. The results demonstrated that with the increase of the brazing tempera-ture,the thickness of the ceramic interface reaction layer would increase. The increase of the brittle compounds inthe joint was not conducive to the release of residual stress. The shear strength of the brazed joints was reduced.With the increase of the holding time,the shear strength of brazed joints first increased and then decreased. Whenthe brazing temperature was 810 ℃ and the holding time was 15 min,the maximum shear strength of the brazedjoint was 33 MPa. The typical microstructure of SiC/Kovar joint was:SiC ceramic/Ti C/Cu(s,s)+Ag(s,s)/Fe2Ti+Fe3Si/Kovar alloy.