激光喷丸强化对半圆孔件疲劳寿命的影响.pdf

第23卷第2期
材料科学与工艺
Vol 23 No.2
2015年4月
MATERIALS SCIENCE &TECHNOLOGY
Apr.2015
doi:10.11951/j.i.1005-0299.20150204
激光喷丸强化对半圆孔件疲劳寿命的影响
章艳,张兴权,左立生,周煜,段士伟,黄志来
(安徽工业大学机械工程学院,安徽马鞍山243002)
摘要:为研究激光喷丸强化对7075-T6铝合金半圆孔件疲劳寿命的影响,对激光喷丸与未喷丸的试样进行了对比试
验,利用X射线应力仪测定其表面残余应力,并对试样进行波劳拉伸试验.用扫描电观察了两类试样疲劳断ロ的形貌,
并采用数理统计方法对其疲劳寿命进行分析.研究表明:经激光丸处理区域,表面存在较大的残余压应力,幅值为
310MPa;未喷丸试样疲劳裂纹条带的宽度为0.7~0.8pm,而喷丸试样疲劳裂纹条带的宽度为0.3~0.4pm,说明喷丸试
样裂纹扩展的速度比未喷丸试样慢很多;激光贲丸后半圆孔件的疲劳寿命比未喷丸的疲劳寿命提高了2.8~7.2倍
关键词:激光喷丸化;半圆孔件;残余应力;疲劳断口;疲劳寿命
中图分类号
文献标志码
文章编号:1005-0299(2015)02-0019-06
Effect of laser shot peening on fatigue life of semicircle hole specimen
ZHANG Yan, ZHANG Xingquan, ZUO Lishen, ZHOU Yu, DUAN Shiwei, HUANG Zhili
( College of Mechanical Engineering, Anhui University of Technology, Ma'anshan 243002, China
Abstract In order to investigate the effect of laser shot peening on fatigue life of 7075-16 Al alloy specimen
with a semicircle hole, the comparative tests were conducted between the laser-peened specimen and the un
peened specimen. The surface residual stresses were measured with model X-350A of X-ray diffraction stress
analyzer and fatigue lests were carried out. The fatigue fracture morphology of two kinds of specimens were
observed with the model SM-7001F of scanning electron microscope, and the fatigue life was comprehensively
studied by statistical analysis. The results show that the laser shot peening can induce the residual compressive
stress in laser-peened zone, and its magnitude reaches to 310 Mpa, The spacing of the fatigue striations in un
peened specimen is roughly 0.7-0.8 km, while the spacing of the fatigue striations in peened specimen is only
0.3-0.4 wm, which indicates that the crack propagation rate of the peened sample is slower than that of the
un-peened case. The average fatigue life of the laser-peened specimen is 2.8-7.2 times than that of the un
peened specimen
Keywords: laser shot peening; semicircle hole specimen residual stress; fatigue fracture; fatigue life
激光喷丸强化是一种新颖的抗疲劳制造技等.与传统的表面处理工艺相比,如机械喷丸
术,它是利用强激光诱导的冲击波作用于材料表滚压强化等,激光喷丸技术只有易于精确控制、非
面,使受冲击区域材料的表层发生塑性屈服,晶粒接触、无污染和形成的残余压应力层较深等独特
细化,产生高密度位错,并伴有残余压应力的产的优势+5,因而在航空航天、铁路运输、汽车制
生,从而提高材料的抗疲劳、抗腐蚀和抗蘑损性能造、核工业等领域有着广的应用前景.日前,国
内外学者已对激光喷丸强化提高紧固孔试件疲劳
收稿日期:2014-05-2.
寿命进行了大量的研究.YANG等°研究了激光
基金项目:国家自然科学基金资助项日(517320):安做省自然冲击强化对2024-13铝合金上紧固孔和止裂孔
科学基金资助项日(09041416):工业大学研究疲劳寿命的影响,研究结果表明,激光冲击强化显
生创新研究基金资助项日(2013058)
作者简介:章艳(1990-),男,硕十研究生
著提高了带有紧固孔和止裂孔铝合金的疲劳寿
通信作者:张兴权,E-mail:zhxq@ahut.cdu.cn.
命.曹子文等?采用双联无传递载荷的狗骨型试