The High Cycle Fatigue Behavior of Surface Treated Electron Beam Melted Titanium Ti6Al4V
The High Cycle Fatigue Behavior of Surface Treated Electron Beam Melted Titanium Ti6Al4V
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表面处理电子束熔炼钛Ti6Al4V的高周疲劳行为
DOI：
10.1115/imece2021-71975
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Ramulu M.
中科院分区：
文献类型：
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作者：
Mojib Melody;Soyama Hitoshi;Sanders Daniel;Arola Dwayne;Ramulu M.
随着增材制造（AM）或3D打印的发展，高应力应用对持久金属部件的需求变得越来越重要。最大的限制之一是AM部件的低疲劳寿命，这是由于各种因素，包括构建方向、表面粗糙度和内部缺陷。为了解决金属增材制造部件的低疲劳行为，人们对在增材制造部件上进行表面处理（例如机加工或抛光）的兴趣增加。由于AM具有生产复杂形状的独特潜力，在打印部件上执行传统表面处理的能力变得困难和有限。本研究探讨了免工具后处理技术对钛合金Ti6Al4V试样疲劳寿命的初步影响，试样进行热等静压（HIP），以及表面处理工艺，包括空蚀喷丸，激光喷丸，喷丸或空蚀磨料表面抛光。对未经处理、HIP和HIP +表面处理的圆柱形电子束熔化（EBM）试样进行了单轴高周疲劳试验。在高放大率下确定了裂纹萌生的位置，并使用微型计算机断层扫描（μCT）评估了内部缺陷的位置。所有试样中裂纹萌生的位置归因于后处理后残留的粗糙表面或亚表面缺陷引起的尖锐空隙。喷丸和抛光钛试样表现出最大的疲劳寿命增加，由于粗糙度的改善和高压缩应力的引入。
With the growth of Additive Manufacturing (AM) or 3D printing, the need for long lasting metal components for high-stress applications is becoming increasingly crucial. One of the biggest limitations is the low fatigue life of AM components due to a variety of factors including build orientation, surface roughness, and internal defects. To address the low fatigue behavior of metal AM components, there is an increase in interest in performing surface treatments such as machining or polishing on additive manufactured components. With AM’s unique potential to produce complex shapes, the ability to perform conventional surface processes on printed parts becomes difficult and limited. Preliminary effects of tool-less post processing techniques on fatigue life titanium Ti6Al4V specimens has been explored in this study with specimens undergoing hot isostatic pressing (HIP), in addition to a surface treatment process including cavitation peen, laser peen, shot peen or cavitation abrasive surface finishing. Uniaxial high cycle fatigue testing has been performed on untreated, HIP, and HIP + surface treated cylindrical electron beam melting (EBM) specimens. The location of crack initiation has been determined under high magnification and the location of internal defects are evaluated using micro-Computer Tomography (μCT). The location of crack initiation in all specimens was attributed to the sharp voids due to the rough surface or the subsurface defects which remained after post processing. The shot peen and polished titanium specimens exhibited the greatest increase in fatigue life due to the improvement in roughness and introduction of high compressive stresses.