摘要
镍基单晶高温合金叶片凝固裂纹抑制及叶片修复过程中单晶完整性对其应用具有重要意义。作用机制是避免熔覆层组织发生柱状晶-等轴晶转变(CET)同时避免重熔区转向杂晶(转向枝晶)。本实验采用激光熔覆技术,探索了DD6合金开裂敏感性与晶粒尺寸的关系,研究了DD6单晶高温基体上GH768合金的多道多层外延生长,明晰了激光工艺参数对单晶组织形成的作用机理。结果表明:随着激光扫描速度增大,晶粒尺寸减小、规则性提高,凝固裂纹减弱,在激光功率P=250 W,扫描速度V=2.5 mm/s,单层提升高度100μm,叠加率41%时,可以消除凝固裂纹同时实现对损坏单晶叶片的初步修复工作。
It is of great significance for the application of Ni-based single crystal superalloy in inhibiting the solidification crack and repairing the blade.The mechanism is to avoid the microstrucure transformed from columnar to equiaxed dendrites(CET),and to avoid the formation of dendritesin remelting zone.In this study,the relationship between crack sensitivity and grain size of DD6 alloy was investigated by laser cladding technology.The epitaxial growth of GH768 alloy deposited on DD6 single crystal superalloy was studied.The mechanism of laser processing parameters on the formation of single crystal structure was clarified.The results showed that with the increased of laser scanning speed,the grain size decreased,the regularity increased,and the solidification crack weakened.When the laser power was 250 W,the scanning speed was 2.5 mm/s,the lifting height was single layer was 100μm,and the superposition rate was 41%,the solidification cracks could be eliminated and the damaged single crystal blade could be initially repaired.
作者
荣鹏
虞文军
王大为
高川云
Rong Peng;Yu Wenjun;Wang Dawei;Gao Chuanyun(Chengdu Aircraft Industrial(Group)Co.,Ltd.,Chengdu,Sichuan610091,China)
出处
《应用激光》
CSCD
北大核心
2020年第6期978-983,共6页
Applied Laser
