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

这一合作研究项目的目标是建立将基于加工的工艺产生的纹理表面的微观结构和微观力学性能与可控工艺变量联系起来的基本原理。为了实现这一点，实验研究将表征在毛化过程中材料去除过程中占主导地位的应变、应变率、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用于微观结构分析。实验将由材料去除力学模型来补充，以估计加工毛化过程中发生的瞬时塑性变形。通过整合这些结果，最终可以预测变形的性质，补充更好地理解表面纹理的几何-地形方面。如果成功，结果的更广泛的影响将是通过设计和创造新的表面纹理来提高结构部件的性能和寿命。基于在此建立的原则，该设计将包括地形和表面完整性属性，例如变形和微观结构。这项研究将为在多个长度尺度上表征变形和微观结构提供实验和分析工具，除其他外，能够理解表面纹理和表面完整性之间的相互作用。这样的理解对于表征质地对结构部件(如轴承、泵和柴油子系统)性能的影响至关重要。我们将从现象学的角度深入了解机械加工和磨损过程中材料去除背后的瞬时变形现象。利用瞬时变形现象作为减少机械加工过程中能量消耗的一种手段，可能会出现机会。

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.