DD3单晶合金瞬间过渡液相扩散焊接头组织与性能

Microstructures and properties of transient liquid phase diffusion bonded joints of DD3 single crystal superalloy

采用粉状中间层合金D1P和非晶态箔状中间层合金D1F对镍基单晶高温合金DD3进行了TLP扩散焊,并对接头组织与性能进行了分析研究。试验结果表明,D1P粉状中间层合金TLP扩散焊接头中存在明显的组织不均匀现象,经过高温长时间保温才可消除,而采用D1F非晶态箔状中间层合金TLP扩散焊DD3合金更易获得与母材组织一致的接头。在合适的规范下,两种中间层合金扩散焊的DD3合金接头980℃持久强度均达到或超过母材的90%。

The microstructures and the stress-rupture properties of TLP diffusion bonded joints of DD3, a nickel-based single crystal superalloy, were investigated. Two interlayer alloys developed for DD3 were employed: D1P, a powder alloy, and D1F, an amorphous foil. The results show that there exists obvious microstructural inhomogeneity in the joint diffusion bonded with D1P, and it requires a long time diffusion under high temperature to eliminate this inhomogeneity. However, when the DD3 alloy was bonded with the amorphous foil interlayer alloy, D1F, it was easier to obtain the joint microstructure identical to that of the base metal. Under proper bonding condition, the stress-rupture property at 980°C of the diffusion bonded DD3 alloy joints reached or surpassed 90% of that of the base metal.