航空材料学报2025，Vol.45Issue(5)：112-122,11.DOI:10.11868/j.issn.1005-5053.2025.000101
小角度晶界对二代镍基单晶高温合金高温蠕变行为的影响
Effect of low angle grain boundary on high-temperature creep behavior of a second-generation nickel-based single-crystal superalloy
摘要
Abstract
In order to investigate the effect of low-angle grain boundary(LAGB)on the high-temperature creep behavior of a second-generation nickel-based single-crystal(SX)superalloy,the high-temperature creep fracture and interrupted experiments are carried out at 1100℃/137 MPa using plate-shaped samples with different grain boundary misorientations.The results show that after standard heat treatment,fine MC carbides are formed at the LAGB with the misorientation of 7°in alloy GB-7,while blocky M6C carbides are formed at the LAGB with the misorientation of 12°in alloy GB-12.The high temperature creep life of the investigated alloys decreases with increasing the misorientation degree.The creep life of alloy GB-12 is only 40%of that of the single crystal alloy.Further investigation reveals that LAGB migration occurrs in both the GB-7 and GB-12 alloys during high-temperature creep,but the migration distance of the GB-12 alloy is lower than that of the GB-7 alloy.Blocky M6C carbides in alloy GB-12 hinder the grain boundary migration,leading to strain concentrations at the LAGB region.Cracks tend to initiate at the low-angle grain boundary either inside GB-12 alloy or on its surface,leading to a significant reduction in its creep life.This study can provide guidance and data support for improving the tolerance of LAGBs in high-temperature creep.关键词
镍基单晶高温合金/小角度晶界/高温蠕变/显微组织/晶界迁移Key words
nickel-based single-crystal superalloy/low-angle grain boundary/high-temperature creep/microstructure/grain boundary migration分类
航空航天引用本文复制引用
尹阔,李龙飞,赵云松,冯强..小角度晶界对二代镍基单晶高温合金高温蠕变行为的影响[J].航空材料学报,2025,45(5):112-122,11.基金项目
国家自然科学基金项目(92360302) （92360302）
