送粉/送丝激光增材修复Inconel 718高温合金V形槽

Comparative study between powder feeding and wire feeding laser additive repairing of V-groove with Inconel 718 alloy

激光熔覆技术已广泛应用于关键部件的增材修复,其熔覆材料的输送主要采用送粉式或送丝式.为研究送粉式与送丝式激光修复对Inconel718高温合金修复质量的影响,结合数值模拟与试验研究对比分析了送粉与送丝方式对激光修复过程中V形槽温度场、熔池轮廓、修复区宏观形貌与微观组织的影响.结果表明,送粉与送丝激光修复V形槽熔池的激光能量吸收与传递关系不同;相比于送丝式,送粉式激光修复过程中的V形槽底部能量集中,导致修复区熔深增大45.5%;送粉式修复过程中粉末以固态及半固态形式冲击进入熔池,修复区表面粗糙度显著增加,同时送粉式修复区晶粒尺寸随修复深度减小逐渐增大,修复区中部区域晶粒取向差异明显.创新点:(1)揭示了送粉与送丝激光修复V形槽熔池的激光能量吸收与传递机制.(2)分析了送粉与送丝激光修复区微观组织及熔池凝固过程的热流演变规律.

Laser cladding technology has been widely used in additive repairing of key components,and powder feeding and wire feeding are the main methods used during this process.In this study,laser additive repairing of V-groove with Inconel 718 powder and wire were conducted to study how they would affect the repairing quality of the superalloy.Numerical simulation and experiments were carried out to compare the effects of powder and wire feeding methods on the V-groove temperature field,molten pool profile,macroscopic morphology and microstructure of the repaired zone during laser repairing.The results indicate that powder and wire feeding methods affect the absorption of laser energy by V-grooves and molten pools.During the powder feeding repairing,the temperature is higher at the bottom of the V-groove,resulting in a 45.5%increase in the melt depth of the repair zone.Powders in state of solid and semisolid were sprayed onto the molten pool,resulting in a coarser surface in the repairing zone.In addition,the grain size in the repaired zone grows gradually as the depth decreases,and the difference in grain orientation in the center of the repaired zone is also significant.Highlights:(1)Laser energy absorption and transfer mechanism in the molten pool were revealed during laser additive repairing of V-groove with powder feeding and wire feeding methods.(2)The microstructure of the repaired zone and the heat flow evolution during the solidification of the molten pool were analyzed both with powder feeding and wire feeding methods.