Collaborative Research: Deformation Phenomena in Surface Texturing by Machining-Based Processes

该合作研究项目的目标是建立将基于加工的工艺创建的纹理表面的微观结构和微观机械性能与可控工艺变量联系起来的基本原理。为了实现这一目标，实验研究将表征纹理化材料去除过程中普遍存在的应变、应变速率、温度的热机械变形条件及其对表面完整性的影响。将使用高速成像和图像相关等技术进行变形分析，以及先进的电子显微镜方法和纳米压痕技术进行微观结构分析。这些实验将通过材料去除力学建模来补充，以估计加工纹理过程中发生的瞬态塑性变形。通过整合这些结果，最终可以预测变形的性质，从而补充更好理解的表面纹理的几何地形方面。如果成功，结果的更广泛影响将是通过设计和创建新颖的表面纹理来提高结构部件的性能和寿命。基于本文建立的原理，该设计将结合形貌和表面完整性属性，例如变形和微观结构。该研究将为表征多个长度尺度的变形和微观结构提供实验和分析工具，使人们能够理解表面纹理力学和表面完整性之间的相互作用。这种理解对于表征纹理对轴承、泵和柴油子系统等结构部件性能的影响至关重要。将获得对加工和磨损过程中材料去除的瞬态变形现象的现象学见解。利用瞬态变形现象作为减少加工过程中能量耗散的手段的机会可能会出现。

The objective of this collaborative research project is to establish the fundamental principles that relate microstructure and micro-scale mechanical properties of textured surfaces created by machining-based processes to the controllable process variables. To accomplish this, an experimental study will characterize thermo-mechanical deformation conditions of strain, strain rate, temperature, that prevail during material removal in texturing and their effects on surface integrity. Techniques such as high-speed imaging and image correlation for deformation analysis, and advanced electron microscopy methods and nano-indentation for microstructure analysis, will be used. The experiments will be complemented by modeling of mechanics of material removal to estimate the transient plastic deformation that occurs in texturing by machining. By integrating these results, the nature of the deformation can eventually be predicted, complementing the much better understood geometric-topographic aspects of surface texture.If successful, the broader impact of the results will be improved performance and life of structural components through design and creation of novel surface textures. Based on the principles established herein, this design will incorporate both topography and surface integrity attributes, such as deformation and microstructure. The research will provide experimental and analytical tools for characterizing deformation and microstructure at multiple length scales, enabling among other things, understanding of the interplay between mechanics of surface texturing and surface integrity. Such an understanding is essential for characterizing the effects of texture on performance of structural components such as bearings, pumps, and diesel fuel sub-systems. Phenomenological insights will be obtained into transient deformation phenomena underlying material removal in machining and wear processes. Opportunities will likely emerge for exploiting the transient deformation phenomena as a means for reducing energy dissipation in machining processes.