Development of micro diamond grinding tool with micro EDM and composite electroforming

摘要

This study presents a novel micro diamond tool 200μm in diameter that allows precise and micro grinding tool during miniature die machining. A novel integrated process technology is proposed that combines "micro EDM" with "precision composite electroforming" for fabricating low-cost micro diamond tools. First, the metal substrate is cut down to 50μm in diameter using WEDG, then, per composite electroforming the micro diamonds with 0-2μm grain is "plated" on the surface of the substrate, thereby becoming the multilayer and micro grinding tool. The thickness of the electroformed layer is restricted within 25μm. The nickel and diamond are the bonder and cutter, respectively. To generate good convection for the electroforming solution, a designed partition with an array of drilled holes array is recommended and verified to effectively decrease the impact energy of the circulatory electroforming solution and increase the dispersion of the diamond grains and displacement of the nickel ions. Experimental results indicated that good circularity of diamond tool can be obtained by arranging the nickel spherules array in the anode. To allow the diamond grains to converge toward the cathode and thereby increase the reposing opportunities of the diamond, a miniature funnel mold that increases the concentration of diamond grains around cathode is designed and then the distribution of the diamond grains on the substrate surface is improved.