FGH97合金过渡液相焊工艺研究

Process Research on TLP Bonding of FGH97 Superalloy

以BNi92SiB合金作为中间层材料对FGH97合金进行了过渡液相焊,研究了焊接温度为1150℃不同保温时间条件下接头的组织变化和性能。结果表明:当保温时间为3h时,焊缝已经完成等温凝固;保温时间为6h时,焊缝组织和扩散区的硬度已与母材相近,焊缝与其他各区的平均显微硬度差异减小,波动范围在60HV以内。经1150℃/6h的热循环后,FGH97合金中小尺寸的二次γ'相数量增加并伴有长大的倾向,部分大尺寸的一次γ'相发生球化,但对母材的硬度影响不大。

Transient liquid phase （TLP） bonding was used to weld FGH97 superalloy with BNi92SiB interlayer at 1150℃. The effect of the different temperature-keeping time on microstructure and properties of joint was studied. The results revealed that isothermal solidification of the joint was accomplished as the temperature-keeping time was more 3h, and the microstructure of the joint and micro- hardness of DAZ were similar to those of the base metal and the value difference of microhardness between the seam and other zone of joint was less than 60HV after when the temperature-keeping time was 6h. The smaller secondary y＇ phase increased in amount and grew coarser and the primary y＇ phase tended to be spheroidized after thermal cycling at 1150℃ for 6h compared with the as-HIPed FGH97 superalloy. However, the microhardness of the parent metal was not badly influenced by bonding thermal cycle.