Co-based superalloy GH159 and Ni-based superalloy GH4169 have been successfully joined by laser beam welding and the effect of heat input on microstructure and properties of dissimilar joints were investigated systematically. The results showed that weld seams exhibited a nail shape and full penetration was attained at all dissimilar joints. Increasing grain size towards the fusion zone (FZ) were observed in the heat affected zone (HAZ) on the GH159 side while an increasing dissolution of γ′ and γ′ towards the FZ was attained at the HAZ on the GH4169 side. These resulted in decreasing microhardness towards FZ. Tensile failure was found in the FZ with the lowest microhardness. Meanwhile, the ultimate tensile strength (UTS) of the dissimilar joints increased with the decreasing of heat input. The high UTS of dissimilar joint with low heat input can be ascribed to the lower volume fraction of the Laves phase and the smaller dendrite arm spacing.

钴基高温合金GH159和镍基高温合金GH4169通过激光束焊接成功连接，系统研究了热输入对异种接头组织和性能的影响。结果表明，焊缝呈现钉状，并且在所有异种接头处均达到完全熔透。在 GH159 侧的热影响区 (HAZ) 中观察到晶粒尺寸向熔合区 (FZ) 增加，而γ ' 和γ 的溶解增加′ 在 GH4169 一侧的 HAZ 处达到 FZ。这些导致朝向 FZ 的显微硬度降低。在具有最低显微硬度的 FZ 中发现了拉伸破坏。同时，异种接头的极限抗拉强度（UTS）随着热输入的减少而增加。具有低热输入的异种接头的高 UTS 可归因于 Laves 相的较低体积分数和较小的枝晶臂间距。