钴基钎料钎焊K465合金大间隙接头组织与性能

采用Co45Ni Cr WB钴基钎料,预填FGH95镍基合金粉,在1220℃不同保温时间下对K465高温合金进行0.5 mm大间隙真空钎焊实验,研究钎缝组织构成及不同保温时间对钎缝组织与接头性能的影响。结果表明:钎缝组织由合金粉颗粒及颗粒间硼化物相构成,颗粒内为γ和γ'双相组织和少量小块状硼化相,颗粒间是高Cr,W和Nb的硼化物相;钎焊时随保温时间延长合金粉长大,化合物相合并长大;合金粉比例高、保温时间适当获得钎缝中化合物相细小弥散分布,对接头性能有利;钎焊保温30~60 min时接头持久性能较高。

Microstructure and Mechanical Properties of Wide-gap Brazed Joints of K465 Alloy Using Cobalt-base Brazing Alloy

Vacuum brazing of K465 superalloy was carried out by using Co45NiCrWB cobalt-base filler metal at 1220 ℃ for different holding time,and the joint clearance was 0.5 mm pre-filled with FGH95 nickel-base superalloy powder.The effect of the structural constitution of brazed different holding time of temperature on the brazed joint microstructure and properties.The results show that the brazing seam is composed of alloy powder particles and borides among them.It is two-phase structure of γ and γ′ with a few small blocks of borides in the powder particles,and there exists phases rich in Cr,W and Nb elements.The powder particles are growing along the holding time during the brazing process,while their combination is expanded.It is good for stress rapture properties of joints that borides was fine in brazing seam with more superalloy powder and proper holding time.And the joints brazed for 30-60 min show higher stress rapture properties.