超音速火焰喷涂WC-17Co涂层的高速磨削机理试验研究

发布时间：2018-03-31 05:32

本文选题：超音速火焰喷涂技术　切入点：WC-Co涂层　出处：《中国机械工程》2016年10期

【摘要】：针对超音速火焰喷涂WC-17Co高硬涂层的加工难题,对WC-17Co涂层进行了高速/超高速磨削试验。通过考察不同金刚石砂轮和磨削工艺参数对磨削力、磨削温度和表面残余应力、表面/亚表面微观形貌和表面粗糙度的影响,讨论了最大未变形切屑厚度与比磨削能的内在关系,分析了磨削温度对表面残余应力的作用规律,探讨了法向磨削力对涂层亚表面损伤的作用规律。结果表明:WC-17Co涂层磨削去除是脆性和延性去除并存;提高砂轮线速度将使磨削力先快速减小后缓慢增大,磨削温度持续升高,涂层磨削从脆性去除转为延性去除的趋势也逐渐增强,表面残余应力由压应力逐渐转变为拉应力,而磨削高温引起涂层热塑性变形是表面残余应力状态转变的根本原因。涂层亚表面磨削损伤层平均深度随法向磨削力的增大而变大。提高砂轮线速度、降低工作台速度和减小磨削深度均能增大涂层磨削塑性去除的比例。
[Abstract]:In order to solve the problem of processing WC-17Co high hardness coating by supersonic flame spraying, the high speed / super high speed grinding test of WC-17Co coating was carried out. The grinding force, grinding temperature and surface residual stress of different diamond wheel and grinding process parameters were investigated. The effects of surface / subsurface morphology and surface roughness are discussed. The relationship between maximum undeformed chip thickness and specific grinding energy is discussed, and the effect of grinding temperature on surface residual stress is analyzed. The effect of normal grinding force on the subsurface damage of coating is discussed. The results show that the removal of WC-17Co coating is brittleness and ductility removal, and increasing the linear speed of grinding wheel will make the grinding force decrease rapidly and then increase slowly, and the grinding temperature increases continuously. The trend of coating grinding from brittleness to ductility is increasing, and the surface residual stress changes from compressive stress to tensile stress. The thermal plastic deformation of the coating caused by high temperature grinding is the fundamental cause of the surface residual stress state transformation. The average depth of the damaged layer increases with the increase of the normal grinding force, and the linear velocity of the grinding wheel is increased. The reduction of worktable speed and grinding depth can increase the plastic removal ratio of coating grinding.
【作者单位】：湖南大学国家高效磨削工程技术研究中心;
【基金】：国家自然科学基金资助项目(51475157) 国家科技重大专项(2011ZX04014-021)
【分类号】：TG580.6

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