摘要
针对K24镍基铸造合金材料表面粗糙度大引起吸收保护层贴合不紧密的问题,提出采用无保护层激光冲击(LSPw C)方法对K24合金进行强化,利用高周疲劳实验验证其强化效果,并从残余应力、微观组织方面讨论疲劳性能改善机理。实验结果表明:相对于原始叶片,LSPw C后的模拟叶片的疲劳强度提高16%,保温后疲劳强度提高11%。LSPw C在试样表层诱导产生高幅值残余压应力和高密度位错,从而提高模拟叶片的疲劳性能;保温后,大部分残余压应力发生松弛,位错结构具有较好的热稳定性,这是保温后模拟叶片疲劳性能提高的主要原因。
Protective layers can not fit well with the surfaces of the materials due to the surface roughness of the K24 nickel based alloy is high. So the laser shock processing without coating（LSPw C） is carried out on the K24 alloy and the high cycle fatigue tests are conducted to verify the reinforcement effect. The mechanisms of the residual stress and microstructures to fatigue performances are discussed. The results show that, compared with the untreated specimen, the fatigue strength of the specimen treated by LSPw C is improved by 16% and that after heat preservation is improved by 11%. Under the effects of the compressive residual stress and high density dislocations that induced by LSPw C, the fatigue performances of the specimens are improved. After heat preservation, the majority of compressive residual stress release, the dislocations have great stability, and this is the main cause of the high cycle fatigue performance improvement.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2015年第10期65-71,共7页
Chinese Journal of Lasers
基金
国家973计划(2015CB057400)
国家自然科学基金(51205406)
陕西省自然科学基金(2012JQ6012)
关键词
激光技术
高周疲劳
无保护层激光冲击强化
K24合金
微观组织
残余压应力
laser technique
high cycle fatigue
laser shock processing without coating
K24 alloy
microstructure
residual compressive stress
