无氧铜超精加工表面微观形貌的分形维数表征

发布时间：2019-03-19 09:41

【摘要】：单点金刚石超精密加工能够获得纳米级的低粗糙度表面。进一步的实验表明,采用该工艺进行退火态无氧铜切削,已加工表面在刀痕基础上还会出现清晰的晶界浮凸现象。传统的粗糙度概念无法有效表征与区分含有晶界浮凸信息的超精加工表面微观形貌。引入分形维数概念,采用该理论中尺码法对无氧铜超精加工表面的微观形貌进行分形维数计算;为降低切削刀痕信号干扰、突出晶界浮凸信息,设计表面信号带阻滤波方法。计算结果表明,超精加工后的表面分形维数包含了加工刀痕与晶界浮凸信息,由于两者尺度相近,传统的粗糙度测量无法区分其差异;采用带阻滤波与尺码法耦合方式,能够有效识别晶界浮凸特点,定量地反映微观尺度下超精加工表面的形貌特征信息。
[Abstract]:Single-point diamond ultra-precision machining can obtain nano-scale low roughness surface. Further experiments show that there is a clear grain boundary bump phenomenon on the machined surface on the basis of the cutter mark when the annealed oxygen-free copper cutting is carried out by this process. The traditional concept of roughness can not effectively characterize and distinguish the micro-morphology of ultra-precision machined surfaces with grain boundary bump information. The concept of fractal dimension is introduced and the fractal dimension of the surface morphology of oxygen-free copper superfinishing is calculated by using the method of scale in the theory. In order to reduce the interference of cutting tool mark signal and highlight the convex information of grain boundary, the band-stop filtering method of surface signal is designed. The calculation results show that the surface fractal dimension after ultra-precision machining contains machining tool mark and grain boundary bump information. Because of the similarity of the two scales, the traditional roughness measurement can not distinguish the difference between the machining tool marks and grain boundary buoyancy information. The coupling method of band-stop filter and scale method can effectively identify the characteristics of grain boundary bumps and quantitatively reflect the morphology information of ultra-precision machined surfaces at micro-scale.
【作者单位】：表面物理与化学重点实验室;清华大学精密超精密制造装备及控制北京市重点实验室;
【基金】：北京市自然科学基金面上项目(3152013) 清华大学摩擦学国家重点实验室自主科研重点项目(SKLT2013A01)
【分类号】：TG506

【相似文献】