材料期刊网

K465镍基高温合金为母材,FGH95镍基合金粉为预填粉末,采用预填高熔点粉末的方法对0.5mm大间隙接头进行钎焊,研究不同保温时间对钎缝组织与接头性能的影响.结果表明:1220℃保温0.5h获得的钎缝组织由合金粉颗粒及颗粒间的相构成,颗粒内为γ和γ'两相组织,颗粒间为γ和γ'两相为基体的硼化物、硅化物及γ+γ'共晶组织;随钎焊保温时间延长,合金粉颗粒长大,化合物相及γ+γ'共晶组织合并、总量减少;钎焊保温时间为0.5～16h时,接头平均持久寿命由31.59h提高至54.58h,但不易获得高性能等温凝固接头.

The joint clearance with 0.5mm was brazed with pre-filled high-melting powder method,by using K465 nickel-base superalloy as base metal,FGH95 nickel-base superalloy powder as pre-filled powder.The effects of different holding time on microstructure and mechanical properties were investigated.The results show that the brazing seam microstructure of the joints brazed at 1220 ℃ for 0.5h composes of alloy powder particles and phases among the particles.The microstructure is a two-phase structure of γ and γ'inside the powder particles,and among the particles are γ and γ'two-phase based borides,silicides and γ+γ'eutectics.With the increase of holding time,the powder particles grow bigger,the compounds and γ+-γ'eutectics merge together,leads to the decrease of the amount of compounds and γ-+γ'eutectics.The holding time is prolonged from 0.5h to 16h,the average rupture life increases from 31.59h to 54.58h,but it is not easy to achieve the isothermally solidified joints with good mechanical properties.