LSP to improve vibration fatigue performance of deflation valve lever
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摘要: 针对某型发动机放气活门主动连杆转接R处的疲劳断裂问题,进行了主动连杆激光冲击强化工艺研究;完成了原型件和激光冲击强化、喷丸及加大R3种处理工艺后主动连杆振动疲劳对比试验.结果表明,在317MPa的应力水平下,激光冲击强化、喷丸和加大R后主动连杆疲劳寿命分别为原型件的5.24倍、3.89倍及1.36倍;与其它2种工艺相比,激光冲击强化具有强化效果好、工艺稳定性高、易于实现等优点,是截至目前减少主动连杆疲劳断裂故障的最佳处理工艺.主动连杆激光冲击强化后表面粗糙度较小,产生深度约1.4mm的高数值残余压应力层,表层晶粒细化至纳米晶并伴随高密度位错.三者共同作用可以有效缓解转接R处的应力集中,抑制疲劳裂纹在转接R处的萌生和扩展,是主动连杆振动疲劳寿命提高的主要原因.Abstract: In order to solve the fatigue failure of the valve lever fixed in certain aeroengine, the technology of laser shock processing (LSP) on the valve lever was studied. Then, the valve levers of prototype and valve levers processed by LSP, shot peening (SP) and enlarge R were applied to vibration fatigue test. The results show that at the vibrating stress level of 317MPa, compared with the prototype, LSP, SP and enlarge R could increase the fatigue life by 424%, 289% and 36% distinguishably. The effectivity, stability and operability of LSP make it the best way to decrease fatigue failure of the valve lever at the present time. The LSP strengthening effect on valve lever is attributed to the low roughness, the high numerical compressive residual stress field about 1.4mm in depth and the grain refinement to nanocrystal accompanied with high density dislocation. The three factors above are the main reasons what LSP could prolong the fatigue life of valve lever, because that they work together could efficiently release the stress concentration at R area as well as restrain the initiation and propagation of fatigue crack.
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Key words:
- valve lever /
- laser shock processing /
- fatigue life /
- roughness /
- compressive residual stress /
- nanocrystal
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[1] Montross C S,Wei Tao,Ye Lin,et al.Laser shock processing and its effects on microstructure and properties of metal alloys: a review[J].International Journal of Fatigue,2002,24:1021-1036 [2] 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,2004,39:2707-2716 [3] Zhang Yongkang,Chen Jufang,Xu Renjun.Experimental research of laser shock strengthing AM50 magnesium alloy[J].Chinese J Lasers,2008,35(7):1068-1072 [4] Sano Y,Obata M.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 [5] 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(2/3/4):265-270 [6] Cheng G J,Shehadeh M A.Multiscale dislocation dynamics analyses of laser shock peening in silicon single crystals[J].International Journal of Plasticity,2006,22(12):71-94 [7] 《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 Aeronautical Manufacture Engineering Handbook Edits Committee.Aeronautical manufacture engineering handbook[M].Beijing:Aerospace Industry Press,1997(in Chinese) [8] 但福堂,陈东林,李曙林,等.飞机发动机强度[M].西安:空军工程大学工程学院出版社,2002 Dan Futang,Chen Donglin,Li Shulin,et al.Intensity of aeroengine [M].Xi-an:Press of Engineering Institute,Air Force University,2002(in Chinese) [9] 马壮.航空发动机部件激光冲击强化应用基础研究 .西安:空军工程大学工程学院,2008 Ma Zhuang.Fundamental research of Laser shock processing used on aero-engine parts .Xi'an:Engineering Institute of Air Force University,2008(in Chinese) [10] 马康民,龙霓东.航空材料及应用[M].西安:空军工程大学工程学院出版社,1995 Ma Kangmin,Long Nidong.Aero-material and its application [M].Xi'an:Press of Engineering Institute,Air Force University,1995(in Chinese) [11] Lu K,Lu J.Surface nanocrystallization(SNC) of metallic materials-presentation of the concept behind a new approach[J].J Mater Sci Techno,1999,15:193-197 -
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