激光冲击强化对钛合金棒件疲劳寿命的影响

发布时间：2018-02-22 00:32

本文关键词： 激光冲击强化残余应力有限元分析 TC-DT 棒件　出处：《激光与红外》2017年09期 　论文类型：期刊论文

【摘要】：为了研究激光冲击对TC4-DT钛合金圆棒残余应力分布及疲劳特性的影响,采用ABAQUS有限元软件分析了不同冲击载荷下圆棒最小直径截面内残余应力的分布,并对试样先后进行了激光冲击强化试验和拉-拉疲劳试验,最后对疲劳断口形貌进行了对比分析。结果表明,圆棒试样会在表面及近表面形成残余压应力层,在内部及中心区域产生拉应力,且表面残余压应力和内部拉应力皆随冲击载荷的增大而增大;内部拉应力区域面积远大于表面压应力层面积,致使疲劳裂纹扩展加速,从而导致疲劳寿命降低,对圆棒试件的拉-拉疲劳性能产生不利影响;圆棒试样经激光冲击强化后疲劳裂纹源向内部转移,且位于内部最大拉应力区域。该研究对轴类零件经激光冲击强化后的应用条件具有一定的参考价值。
[Abstract]:In order to study the effect of laser shock on the residual stress distribution and fatigue characteristics of TC4-DT titanium alloy rod, the residual stress distribution in the minimum diameter section of the rod under different impact loads was analyzed by ABAQUS finite element software. The laser shock hardening test and tensile fatigue test were carried out successively. Finally, the fatigue fracture morphology was compared and analyzed. The results showed that the residual compressive stress layer was formed on the surface and near the surface of the round bar specimen. Tensile stress is produced in the inner and central region, and the residual compressive stress and internal tensile stress increase with the increase of impact load, and the area of internal tensile stress is much larger than the area of surface compressive stress layer, which results in accelerated fatigue crack growth. Thus, the fatigue life of the specimen decreases and the tensile fatigue property of the round rod specimen is adversely affected, and the fatigue crack source of the round rod specimen is transferred to the inside after the laser shock hardening. This study has some reference value for the application condition of shaft parts strengthened by laser shock.
【作者单位】：江苏大学机械工程学院;中航工业成都飞机工业(集团)有限公司;中航工业成都飞机设计研究所;
【基金】：国家自然科学基金项目(No.51075193) 国防科工局项目(No.GKGJ2060)资助
【分类号】：TG146.23;TN249

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