Measuring Thermomechanical Material Response During Micromachining by In Situ Scanning Electron Microscopy

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

The objective of this research is to elucidate the deformation mechanics of chip formation in micromachining using in situ scanning electron microscopy. In this study, metal cutting will be performed on a customized sub-stage within the sample chamber of a scanning electron microscope in a configuration that enables direct visualization and characterization of the deformation zone in secondary and backscattered electron imaging modes. Subsequently, the mechanics of deformation will be delineated in situ through digital image correlation of sequences of secondary electron micrographs of the micromachining process. The microstructural consequences of micrometer-scale surface generation will be studied using electron backscattered diffraction techniques. Together, these characterizations can enable a detailed demarcation of the thermomechanical material response during material removal at small length-scales. If successful, this research may significantly enhance the current level of understanding of the micromachining process and possibly supplant the extant experimental paradigms which offer at best, a post-deformation, ex situ scheme entirely devoid of the dynamic details of the operative micromechanisms. It is envisioned that the interdisciplinary framework inherent to this research may offer unique opportunities for multi-faceted development of graduate students by bringing together elements of vacuum device design, quantitative electron microscopy as well as computational image processing methodologies. An impact on advancing undergraduate education is envisaged via integration with existing courses in manufacturing and creation of a new course aimed at seniors and juniors in the Industrial, Mechanical and Materials Science disciplines.