摘要
采用超音速微粒轰击(SFPB)技术对层片组织的TC11钛合金进行表面纳米化处理,对比研究了表面纳米化处理前、后TC11钛合金的室温高周疲劳行为;借助光学显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM)和X射线衍射仪(XRD)对比分析了高周疲劳断口及断口附近的微观组织形貌。结果表明:经SFPB处理后在钛合金表层产生了30~50μm厚的纳米层,纳米晶尺寸在5~15 nm左右;疲劳性能得到明显提高,在相同应力级别下的疲劳寿命提高了约8~10倍,疲劳条带宽度变窄,且随着加载级别的降低,疲劳寿命提高的倍数逐渐增加;SFPB前、后疲劳断口均由疲劳源区、裂纹扩展区、瞬断区三部分组成,但SFPB处理后的疲劳源由处理前的表层移至次表层;SFPB处理态试样疲劳加载后表层组织仍为纳米量级,但次表层组织中出现大量的形变孪晶、位错缠结以及少量的形变诱导马氏体组织。
The high cycle fatigue behavior of TC11 titanium alloy with lamellar structure before and after surface nanocrystallization was studied by supersonic fine particle bombardment(SFPB).The microstructure of the high cycle fatigue fracture and its vicinity were compared and analyzed by means of optical microscope(OM),scanning electron microscope(SEM),transmission electron microscope(TEM)and X-ray diffraction(XRD).The results show that there are 30-50μm thick nanolayers on the surface of titanium alloy after SFPB treatment,and the size of nanocrystalline is about 5-15 nm.The fatigue performance is improved obviously and the fatigue life is increased about 8-10 times under the same stress level,the fatigue striation width becomes narrow,and the multiple of fatigue life increases gradually with the decrease of loading level.The fatigue fracture surface before and after SFPB treatment consists of the fatigue source zone,the crack propagation zone and the instantaneous fracture zone,but the fatigue source after SFPB treatment moves from the surface layer before treatment to the subsurface.After fatigue loading,the surface microstructure of SFPB treated specimens is still in nanometer scale,but there are a lot of deformation twins,dislocation tangles and a small amount of deformation-induced martensite in the subsurface microstructure.
作者
武永丽
熊毅
陈正阁
查小琴
岳赟
刘玉亮
张金民
任凤章
WU Yong-li;XIONG Yi;CHEN Zheng-ge;ZHA Xiao-qin;YUE Yun;LIU Yu-liang;ZHANG Jin-min;REN Feng-zhang(School of Materials Science and Engineering,Henan University of Science andTechnology,Luoyang 471023,Henan,China;Collaborative Innovation Center ofNew Nonferrous Metal Materials and Advanced Processing Technology Jointly Established by the Ministry of Science and Technology,Luoyang 471023,Henan,China;State Key Laboratory of Laser Interaction with Matter,Northwest Institute of Nuclear Technology,Xi'an 710024,China;The 725th Research Institute of China Shipbuilding Industry Corporation,Luoyang 471023,Henan,China)
出处
《材料工程》
EI
CAS
CSCD
北大核心
2021年第5期137-143,共7页
Journal of Materials Engineering
基金
国家自然科学基金资助项目(U1804146,51801054)
河南省高校科技创新人才支持计划项目(17HASTIT026)
河南省外国专家与引智项目(HNGD2020009)
河南科技大学科技创新团队资助项目(2015XTD006)。
关键词
超音速微粒轰击
TC11钛合金
表面纳米化
高周疲劳
微观组织
supersonic fine particle bombardment
TC11 titanium alloy
surface nanocrystallization
high cycle fatigue
microstructure
