摘要
通过对TA15钛合金进行激光冲击强化,研究了不同工艺参数对TA15钛合金残余应力和力学性能的影响。实验结果表明,激光冲击强化可以细化晶粒尺寸,有效提高材料表面显微硬度和残余压应力,且表面显微硬度和残余压应力随着激光能量和冲击次数的增加而增大。当激光能量为7 J,光斑直径为Φ2 mm,冲击3次时,激光冲击强化后表面显微硬度提高21.6%,强化层深度可达1 mm,表面残余压应力高达-730 MPa。激光冲击强化后经400℃热处理并保温5和10 h后,发现引入的残余压应力降低幅度较小,仅为8%,具有较高的热稳定性。当激光能量为5 J,光斑直径为Φ2 mm,冲击2次时,激光冲击强化后可以获得最优的疲劳性能,试样在650 MPa应力水平下的疲劳寿命大于10^6次,相对于未强化试样提高了3倍,这是由于激光冲击强化使疲劳源由试样表面转移到了次表面,可以有效抑制疲劳裂纹的萌生和扩展。
By conducting laser shock peening(LSP)for TA15 titanium alloy,the influence of different process parameters on residual stress and mechanical properties of TA15 titanium alloy was studied.The experimental results show that LSP can refine the grain size and increase the surface microhardness and residual compressive stress of material,and the surface microhardness and residual compressive stress increase with the increase of laser energy and shock time.When the laser energy is 7 J,the spot diameter isΦ2 mm and the shock time is three,the surface microhardness is increased by 21.6%,the strengthened layer depth reaches 1 mm,and the surface residual compressive stress is up to-730 MPa after the LSP.When the samples are heated at 400℃and holding for 5 and 10 h after LSP,it is found that the reduce extent of residual compressive stress is small,only by 8%,and the thermal stability is higher.When the laser energy is 5 J,the spot diameter isΦ2 mm and the shock time is two,the fatigue performance is the best after LSP,the fatigue life of sample is more than 10^(6)times with the stress level of 650 MPa,which is increased by 3 times compared with that of the unstrengthened samples.This is because LSP makes the fatigue source transfers from the sample surface to the subsurface,which can effectively inhibit the nucleation and propagation of fatigue crack.
作者
焦清洋
韩培培
陆莹
赵栋
乔红超
赵吉宾
JIAO Qing-yang;HAN Pei-pei;LU Ying;ZHAO Dong;QIAO Hong-chao;ZHAO Ji-bin(AVIC Shenyang Aircraft Corporation,Shenyang 110850,China;Shenyang Institute of Automation,Chinese Academy of Sciences,Shenyang 110016,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2021年第3期146-152,共7页
Journal of Plasticity Engineering
基金
国防基础科研项目(JCKY2018205B023)。
关键词
激光冲击强化
TA15钛合金
硬度
残余压应力
热稳定性
疲劳性能
laser shock peening
TA15 titanium alloy
hardness
residual compressive stress
thermal stability
fatigue performance
