ABSTRACT This work contributes to the surface topographical study of miniature Ti-alloy coated samples prepared by the micro-electrical discharge coating process using powder mixed dielectric medium. Two phases of experiments were conducted, first phase: using tungsten disulfide mixed in de-ionized water and second phase: using molybdenum disulfide powders mixed in deionized water. The produced micro-parts from both the phases of experiments were characterized for micro-hardness, indentation depths, wettability (in terms of the surface contact angle), residual stress, surface roughness, and surface crack density. The results indicated that MoS2 coating is superior as compared to WS2 coating obtained through the micro-EDM process for tribological applications where lubrication is necessary. The WS2 coated samples have micro-hardness ranging from 705.8 HV to 880.34 HV, surface roughness from 0.604 microns to 0.660 microns, and a comparatively higher surface crack density and residual stresses are developed on the recast surface than the samples coated with MoS2 powders. The samples coated with MoS2 powders have a micro-hardness variation from 658.21 HV to 714.21 HV, surface roughness between 0.561 μm to 0.650 μm.

中文翻译：

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μEDM涂层钛合金微型部件的表面完整性和残余应力分析

摘要这项工作有助于通过使用粉末混合电介质的微放电涂层工艺制备的微型钛合金涂层样品的表面形貌研究。进行了两个阶段的实验，第一阶段：使用混合在去离子水中的二硫化钨和第二阶段：使用混合在去离子水中的二硫化钼粉末。从两个实验阶段生产的微零件都具有显微硬度、压痕深度、润湿性（根据表面接触角）、残余应力、表面粗糙度和表面裂纹密度的特征。结果表明，在需要润滑的摩擦学应用中，与通过微电火花加工工艺获得的 WS2 涂层相比，MoS2 涂层更优越。WS2 涂层样品的显微硬度范围为 705.8 HV 至 880.34 HV，表面粗糙度为 0.604 微米至 0.660 微米，与涂覆有 MoS2 粉末的样品相比，在重铸表面上产生了相对更高的表面裂纹密度和残余应力。涂有二硫化钼粉末的样品具有从 658.21 HV 到 714.21 HV 的显微硬度变化，表面粗糙度在 0.561 μm 到 0.650 μm 之间。