Al_2O_3陶瓷/AgCuTi/GH99高温合金的钎焊接头力学性能

Mechanical Properties of Alumina Ceramic/AgCuTi/GH99 Superalloy Brazed Joints

采用AgCuTi钎料对Al_2O_3陶瓷与GH99高温合金进行了钎焊连接,研究了工艺参数(连接温度、保温时间)的变化对接头力学性能的影响,并分析了不同参数下接头的断裂位置。结果表明:保温5 min时,在不同的连接温度下进行钎焊,随着连接温度的升高,接头的抗剪强度先增大后减小,在900℃时取得最大值,为127.24MPa,连接温度较低时,主要断裂于Al_2O_3/钎料侧,随着温度的升高,接头TiNi3反应层增厚,因此还有部分断裂于TiNi_3反应层/钎料界面;在连接温度为900℃时,随着保温时间的延长,接头的抗剪强度逐渐降低;保温时间较短时,主要断裂于Al_2O_3/钎料界面;保温时间过长,TiNi_3反应层延伸入钎料中部且厚度大大增加,在该反应层中产生微裂纹,造成接头强度大大降低,此时部分断裂于钎料中部及TiNi_3反应层中。

The Al2 O3 ceramic was brazed to GH99 superalloy using AgCuTi filler alloy.The influence of the process parameters on the mechanical property of the joints was studied.The fracture location of joints under different process parameters was analyzed.The results show that when the holding time is 5 min,the shear strength of joints decreases after increasing to a maximum with the increase in brazing temperature.The maximum is obtained at 900 ℃,which is 127.24 MPa.When the brazing temperature is lower,the fracture is mostly in Al2 O3/filler side.With the increase in brazing temperature,the TiNi3 reaction layer is gradually thickened and parts of the fracture are in the TiNi3 reaction layer/filler interface.At 900℃,with the increase in the holding time,the shear strength of joint gradually decreases.The joints are mainly fractured in the Al2 O3 ceramic/filler interface when the holding time is short.When the holding time is too long,the reaction layer extends into the middle of the solder and the thickness of TiNi3 layer is greatly increased,and the micro crack is produced in the reaction layer,which greatly reduces the strength of the joint,and then the joint is partly fractured in the middle of the filler metal and TiNi3 reaction layer.