激光冲击强化钛合金熔覆修复试件疲劳性能研究

发布时间：2018-03-17 05:17

本文选题：激光技术　切入点：激光熔覆　出处：《中国激光》2015年11期 　论文类型：期刊论文

【摘要】：激光成形修复钛合金构件存在修复区晶粒粗大和残余拉应力,以及不同区域间组织及性能不均匀的问题,导致修复构件的疲劳性能明显降低。本文采用激光冲击强化技术,对激光熔覆修复试件进行了表面强化,研究了激光冲击对其疲劳强度的影响,并从残余应力和微观组织等方面分析了激光冲击提高熔覆试件疲劳强度的原因。结果表明,钛合金基体试件的疲劳强度为401 MPa,激光熔覆试件的疲劳强度为365 MPa,下降了9%;激光冲击强化后,熔覆试件的疲劳强度达到了450.80 MPa,相比基体提高了23.5%。激光冲击强化在试件表层引入了数百兆帕的残余压应力,影响层深度可达430μm,同时可使修复区的组织和性能变得均匀,从而提高了修复试件的疲劳抗力。
[Abstract]:The problems of coarse grain size and residual tensile stress in the repair zone, as well as uneven microstructure and properties among different regions, resulted in the obvious reduction of fatigue properties of the repaired titanium alloy members by laser forming. In this paper, the laser shock strengthening technique is used. The surface strengthening of laser cladding repairing specimen was carried out, the influence of laser impact on fatigue strength was studied, and the reason of laser shock increasing fatigue strength of cladding specimen was analyzed from the aspects of residual stress and microstructure. The fatigue strength of titanium alloy matrix specimen was 401 MPA, and that of laser cladding specimen was 365 MPA, which decreased by 9 parts. The fatigue strength of the cladding specimens reaches 450.80 MPa, which is 23.5m higher than that of the matrix. The residual compressive stress of hundreds of MPA is introduced into the surface of the specimens by laser impact strengthening, the depth of the affected layer can reach 430 渭 m, and the microstructure and properties of the repair zone can be uniform. Thus, the fatigue resistance of the repaired specimen is improved.
【作者单位】：空军工程大学等离子体动力学重点实验室;
【基金】：国家973计划(2015CB057400) 国家自然科学基金(51205406)
【分类号】：TG665;TG146.23

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