Titanium and its alloys are widely used in aerospace, biomedicine, chemical industries, and other fields due to the excellent properties as high specific strength, strong corrosion resistance, and superior biocompatibility. With the development of mechanical industry, especially of aerospace, the higher fatigue performance of titanium alloys is demanded. Generally, fatigue cracking originates from the materials surface, so the surface roughness, residual stress, and microstructure in surface layer are believed to be the dominant factors in affecting the fatigue crack initiation and propagation, as well as the fatigue strength. Thus, by means of the mechanical surface enhancement techniques, the achievement of reducing the surface roughness, introducing the residual compressive stress, improving the surface microstructure and increasing the surface hardness could significantly enhance the fatigue strength. The effects of various mechanical surface treatments, such as deep rolling, shot peening, and laser shock peening, on surface integrity and fatigue properties of Ti-6Al-4V were reviewed in this article. By comparing surface roughness, hardness, residual stress, surface grain size, depth of grain refinement layer, fatigue properties at room and high temperatures, and residual stress relaxation during fatigue of different surface-treated Ti-6Al-4V, the advantages and the limitations of these surface treatments were identified and evaluated.

中文翻译：

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机械表面增强技术对Ti-6Al-4V表面完整性和疲劳性能的影响：综述

钛及其合金由于具有高比强度，强耐腐蚀性和优异的生物相容性等优异性能而广泛用于航空航天，生物医学，化学工业和其他领域。随着机械工业特别是航空航天工业的发展，要求钛合金具有更高的疲劳性能。通常，疲劳裂纹起源于材料表面，因此，表面层的表面粗糙度，残余应力和微观结构被认为是影响疲劳裂纹萌生和扩展以及疲劳强度的主要因素。因此，借助机械表面增强技术，可以降低表面粗糙度，引入残余压缩应力，改善表面微观结构和增加表面硬度可以显着提高疲劳强度。本文综述了各种机械表面处理方法（例如深轧，喷丸处理和激光冲击喷丸处理）对Ti-6Al-4V的表面完整性和疲劳性能的影响。通过比较不同表面处理的Ti-6Al-4V的表面粗糙度，硬度，残余应力，表面晶粒尺寸，晶粒细化层的深度，室温和高温下的疲劳特性以及疲劳期间的残余应力松弛，优点和局限性识别并评估了这些表面处理方法。本文综述了Ti-6Al-4V的表面完整性和疲劳性能。通过比较不同表面处理的Ti-6Al-4V的表面粗糙度，硬度，残余应力，表面晶粒尺寸，晶粒细化层的深度，室温和高温下的疲劳特性以及疲劳期间的残余应力松弛，优点和局限性识别并评估了这些表面处理方法。本文综述了Ti-6Al-4V的表面完整性和疲劳性能。通过比较不同表面处理的Ti-6Al-4V的表面粗糙度，硬度，残余应力，表面晶粒尺寸，晶粒细化层的深度，室温和高温下的疲劳特性以及疲劳期间的残余应力松弛，优点和局限性识别并评估了这些表面处理方法。