ANALYSIS OF POLYCRYSTALLINE DIAMOND MICRO-GRINDING TOOL TOPOGRAPHY USING IMAGE PROCESSING

摘要

Polycrystalline diamond (PCD) micro-grinding tools are shaped using different electro-discharge machining processes among which wire electro-discharge grinding (WEDG) process is widely accepted due to its capability of producing highly precise, ultra-thin and dimensionally accurate tools. Topographical analysis of the tool surface is inevitable as abrasive cutting edge density and grit protrusion heights affect the cutting process and are equally demanding parameters in modeling of the process. Analysis of micro-grinding tool topography and determining the tool surface statistics have always been a vital challenge due to random positioning and orientation of the abrasives on the tool surface. Current study deals with dressing of polycrystalline diamond micro-tool using wire-electro-discharge grinding and thereafter analysis of tool surface topography using novel image processing technique. In contrast to most of the previous experimental studies based on wheel replication and touch probe data to analyze the conventional grinding tool surface, we develop a sequential methodology using various available image processing algorithm tools and its application on the actual 3D surface data of the miniature sized PCD tool to capture the abrasive density and protrusion heights distribution. It is observed that image processing employing leveling, threshold, watershed algorithm and edge detection provided accurate outlook into the tool surface. Static cutting edge density is found to be 165-170 grits (per mm) and its variation with respect to depth into tool surface is also observed.