TiAl与Ni基合金接触反应钎焊接头界面组织及性能

以Ti为中间层实现了TiAl与Ni基合金的接触反应钎焊。采用扫描电镜和电子探针等手段对钎焊接头的界面结构及生成相进行分析,并对接头剪切强度进行测试。结果表明:当钎焊温度为960℃时,钎缝主要由Tiss和Ti2Ni组成;当钎焊温度从960℃升高到1000℃时,钎缝中生成Ti-Al及Al-Ni-Ti化合物,典型界面结构为:GH99/(Ni,Cr)ss/Ti2Ni+AlNi2Ti+TiNi/Ti3Al+Al3NiTi2/Ti3Al+Al3NiTi2/TiAl;钎焊温度继续升高,Ti3Al和Al3NiTi2变得粗大,导致接头性能下降。当钎焊温度为1000℃,保温10min时,接头剪切强度达到最大值233MPa。随钎焊温度的升高,钎缝厚度先增加后减小。

Interfacial Structure and Properties of Reactive Brazing Joints of TiAl/Ni-based Alloy

TiAl alloy and Ni-based alloy were joined by vacuum reactive brazing using Ti foil as the interlayer. Interfacial microstructure and formation phases of the brazed joint were investigated by means of scanning electron microscope and electron probe microanalysis, and shear strength of the joint was determined. The results show that the brazed joint is mainly composed of Tiss and Ti2Ni when brazed at 960 °C; when the brazing temperature increases from 960 °C to 1000 °C, Ti-Al and Al-Ni-Ti compounds form in the brazing seam and the typical interface structure of the brazed joint is GH99/(Ni,Cr)ss/Ti2Ni+AlNi2Ti+TiNi/Ti3Al+Al3NiTi2/Ti3Al+Al3NiTi2/TiAl. Further increasing the brazing temperature results in excessive growth of Ti3Al and Al3NiTi2 phase, which reduces the joining properties. The shear strength of the joint reaches a maximum of 233 MPa when brazed at 1000 oC for 10 min. With the brazing temperature increasing, the thickness of the brazing seam increases firstly and then decreases.