摘要
采用Ag-Cu-Ti钎料及Ag-Cu-Ti+B4C复合钎料对高性能B4C-TiB2-SiC-TiC(BTST)复合陶瓷进行了钎焊连接,分析了 Ag-Cu-Ti钎料在复合陶瓷表面的润湿行为,研究了钎焊温度、保温时间以及B4C含量对接头界面组织及力学性能的影响.结果表明:钎料对BTST复合陶瓷具有良好的润湿性,界面反应主要发生在Ti与复合陶瓷之间,反应产物主要为TiC和TiB.钎焊温度和保温时间显著影响钎焊接头的界面组织和力学性能.随着钎焊温度的提高或保温时间的延长,BTST复合陶瓷侧界面反应层逐渐增厚,钎缝组织趋向于形成Ag-Cu共晶组织,钎焊接头弯曲强度先升高后降低.随着钎料中B4C含量的增加,接头中陶瓷侧反应层厚度急剧降低,钎缝区域组织得到细化,接头强度先升高后降低.当添加B4C颗粒含量(质量分数)为1％,钎焊温度890 ℃,保温时间15 min时,钎焊接头弯曲强度最高为314.2 MPa.
Abstract
Ag-Cu-Ti and Ag-Cu-Ti+B4C composite brazing alloys were used to braze the B4C-TiB2-SiC-TiC(BTST)composite ceramic.The effects of brazing temperature,holding time,and B4C content on the interfacial microstructure and mechanical properties of the joints were investigated.The results show that Ag-Cu-Ti brazing alloy has a good wettability with BTST and Ti reacts with BTST to form TiC and TiB.The thickness of reaction layer increases with the increase in brazing temperature or holding time,and Ag-Cu eutectic alloy forms in the brazing seam.The bending strength of the joints increases first with the brazing temperature or holding time and then decreases.The addition of B4C into the Ag-Cu-Ti refines the microstructure of brazing seam and reduces the thickness of reaction layer.The maximum bending strength of the joint achieved is 314.2 MPa,when the BTST composite ceramic is brazed at 890 ℃ for 15 min by the Ag-Cu-Ti with 1％B4C(mass fraction).
基金项目
安徽省自然科学基金(2208085ME134)
科技部磁约束核聚变能发展研究专项(2015GB121003)
NETL
NSTL
万方数据