TC17钛合金激光喷丸应力场及支持向量机应力热松弛模型
Residual stress of laser peening processed TC17 and stress relax prediction model based on support vector machines theory
-
摘要: 对TC17钛合金进行了不同功率密度下激光喷丸强化,使用X射线衍射仪测试了激光喷丸冲击波诱导的残余压应力场的分布,测试了不同温度真空保温下残余压应力的热松弛规律,最后基于支持向量机理论建立了残余压应力热松弛预测模型,并用试验结果对模型进行验证.研究表明:TC17钛合金在功率密度为4GW/cm2时表层残余压应力场最佳;残余压应力在280℃和450℃真空保温150min后分别有11.24%和27.11%的松弛;在280℃和450℃交替保温160min后应力松弛33.9%;残余压应力在试验温度保温160min后有大部分剩余,可以有效提高TC17钛合金抗疲劳性能、基于支持向量机的预测模型能够较精确的表征TC17钛合金的应力松弛规律,满足工程使用要求,对其他材料表层残余压应力热松弛分析具有借鉴意义.Abstract: TC17 titanium alloy was laser peening (LP) processed by different power densities.X-ray diffraction method was used to measure the residual stress induced by LP.Vacuum thermal retardation at 280℃ and 450℃ for 160min was used to study the residual stress relaxation regularity.The prediction model was based on support vector machines (SVM) theory and the model was verified by experimental results at last.The results show that 4GW/cm2 is the optimal power density to process TC17 titanium alloy.The thermal relaxation is about 11.24%,27.11% at 280℃ and 450℃ for 150min respectively.And relaxation enhances to 33.9% after 280℃ and 450℃ alternate vacuum thermal retardation.The relaxation indicates that the majority of residual stress is preserved,and thus improves the fatigue resistance of titanium alloy.The residual stress prediction model can characterize the relaxation regularity accurately.And the model is useful to analyze the residual stress thermal relaxation of other metals.
-
Key words:
- laser peening /
- residual stress /
- support vector machines /
- thermal relaxation /
- TC17 titanium alloy
-
[1] 《航空制造工程手册》总编委会.航空制造工程手册[M].北京:航空工业出版社,1997. [2] Charles S M,TAO Wei,LIN Ye,et al.Laser shock processing and its effects on microstructure and properties of metal alloys:a review[J].International Journal of Fatigue,2002,24(2):1021-1036. [3] 李伟,李应红,何卫锋,等.激光冲击强化技术的发展和应用[J].激光与光电子学进展,2008,45(12):15-19. LI Wei,LI Yinghong,HE Weifeng,et al.Development and application of laser shock processing[J].Laser & Optoelectronics Progress,2008,45(12):15-19.(in Chinese) [4] Barradas S,Jeandin M,Bolis C,et al.Study of adhesion of protel copper coating of Al2017 using the laser shock adhesion test (LASAT)[J].Journal of Materials Science,2004,39(3):2707-2716. [5] ZHANG Yongkang,CHEN Jufang,XU Renjun.Experimental research of laser shock strengthing AM50 magnesium alloy[J].Chinese J. Lasers,2008,35(7):1068-1072. [6] Sano Y,Obata M,Kubo T,et al.Retardation of crack initiation and growth in austenitic stainless steels by laser peening without protective coating[J].Materials Science and Engineering,2006,417(1-2):334-340. [7] Holmlid L,Badiei S.Laser initiated detonation in Rydberg matter with a fast propagating shock wave,releasing protons with keV kinetic energy[J].Applied Physics Letters,2005,344(2-4):265-270. [8] CHENG Gaojin,Shehadeh M A.Multiscale dislocation dynamics analyses of laser peening in silicon single crystals[J].International Journal of Plasticity,2006,22(12):71-94. [9] 马壮.航空发动机部件激光冲击强化应用基础研究.西安:空军工程大学,2008. MA Zhuang.Fundamental research on laser shock processing used on aero-engine parts.Xi’an:Air Force University,2008.(in Chinese) [10] 冯宝香,毛小南,杨冠军,等.TC4-DT钛合金喷丸残余应力场及其热松弛行为[J].金属热处理,2009,34(4):20-23. FENG Baoxiang,MAO Xiaonan,YANG Guanjun,et al.Residual stress and its relaxation behavior of TC4-DT titanium alloy after shot peening[J].Heat Treatment of Metals,2009,34(4):20-23.(in Chinese) [11] 刘海雷.TC17钛合金激光喷丸研究.西安:空军工程大学,2011. LIU Hailei.Laser shock processing of TC17 titanium alloy.Xi’an:Air Force University,2011.(in Chinese) [12] 纪玲玲,林振山,王昌雨,等.最小二乘回归支持向量机对非线性时间序列预测的试验分析[J].解放军理工大学学报(自然科学版),2009,10(1):92-97. JI Lingling,LIN Zhenshan,WANG Changyu,et al.Experiments on nonlinear time series prediction with least squaresupport vector regression machine[J].J. of PLA University of Sci. and Tech.,2009,10(1):92-97.(in Chinese) [13] 刘莉,徐浩军.支持向量机的可靠度时序预测分析与应用[J].火力与指挥控制,2007,32(11):118-120. LIU Li,XU Haojun.Analysis and application of time series prediction of reliability based on support vector machines[J].Fire Control and Command Control,2007,32(11):118-120.(in Chinese) [14] 尉询楷,李应红,张朴,等.基于支持向量机的时间序列预测模型分析与应用[J].系统工程与电子技术,2005,27(3):530-532. WEI Xunkai,LI Yinghong,ZHANG Pu,et al.Analysis and applications of time series forecasting model via support vector machine[J].System Engineering and Electronics,2005,27(3):530-532.(in Chinese)
点击查看大图
计量
- 文章访问数: 1562
- HTML浏览量: 1
- PDF量: 445
- 被引次数: 0