摘要
对7050-T7451铝合金试样进行激光冲击强化,研究不同激光功率密度和冲击次数对铝合金残余应力和性能的影响。试验结果表明:激光冲击强化可以有效提高试样表面显微硬度,且硬度随着冲击次数的增加而增大,最高达172 HV0.05,较未强化试样提高了17%,硬度影响层深度可达750μm。当激光功率密度为7.28 GW/cm^(2)时,激光冲击1次后试样表面粗糙度为0.279μm,比原始磨削表面的粗糙度下降了22.5%,随着冲击次数的增加,表面粗糙度逐渐增大,但均小于原始表面粗糙度。激光冲击强化可以大幅提高试样表面残余压应力,当激光功率密度为7.28 GW/cm^(2)、冲击3次时残余压应力最大,可达-227.0 MPa。当激光功率密度为4.37 GW/cm^(2)、冲击3次时,激光冲击强化可以有效提高试样的疲劳寿命(大于10^(6)次),相比未强化试样提高2.3倍。激光冲击强化后表面残余压应力和显微硬度大幅提升可以有效抑制疲劳裂纹的萌生和扩展,从而提升7050-T7451铝合金的抗疲劳性能。
Effect of different laser power density and shock times on residual stress and properties of the 7050-T7451 aluminium alloy,the specimens were treated by laser shock processing(LSP).The results show that,laser shock processing can increase the hardness of the specimen,and the hardness increases with the increase of shock times.The maximum surface micro-hardness can reach 172 HV0.05,which is increased by 17%compared with untreated specimen,and the depth of hardened influenced layer is 750μm.When the laser power density is 7.28 GW/cm^(2)and shocked for once,the surface roughness is 0.279μm which is decreased by 22.5%compared with the original ground surface,and the roughness increases with the increase of shock times,but all are less than the original surface roughness.The laser shock processing can increase the residual stress of the specimen.When the laser power density is 7.28 GW/cm^(2) and shock for three times,the maximum surface residual stress is-227.0 MPa.When the laser power density is 4.37 GW/cm^(2)and shock for three times,the fatigue life of the specimen can up to 10^(6) cycles,which is increased by 2.3 times compared to that of the untreated specimen.The higher hardness and residual compressive stress by LSP can effectively prohibit cracking initiation and propagation and then enhance the fatigue property resistance of the 7050-T7451 aluminium alloy.
作者
韩培培
权纯逸
焦清洋
陆莹
赵栋
乔红超
赵吉宾
Han Peipei;Quan Chunyi;Jiao Qingyang;Lu Ying;Zhao Dong;Qiao Hongchao;Zhao Jibin(AVIC Shenyang Aircraft Corporation,Shenyang Liaoning 110850,China;Shenyang Institute of Automation,Chinese Academy of Sciences,Shenyang Liaoning 110016,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2021年第2期190-195,共6页
Heat Treatment of Metals
