Development of micro co-axial diamond wheel-tool array using a hybrid process of electrochemical co-deposition and RWEDM technique

This study presents a novel hybrid technique for fabricating a multi-edged co-axial micro diamond wheel-tool array. The technique combines an electrochemical process with a RWEDM (Rotary Wire Electrical Discharge Machining) technique to precisely electroform a diamond wheel-blank and then produce a co-axial wheel-tool array. A duplex tank design, containing a mini-tank made of porous aluminium-dioxide material is developed for the electrochemical co-deposition of a nickel-based diamond matrix onto a cylindrical aluminium alloy substrate. Optimal conditions for the co-deposition are examined and tested in the production of the wheel-blank. A small RWEDM mechanism that uses permanent magnet tension braking to maintain wire tension and reduce wire vibration is also proposed. The RWEDM process is used for slicing, truing and dressing the grinding edges of the blank. Experimental findings and machining examples show that the proposed novel hybrid process can successfully fabricate a co-axial diamond wheel-tool with a grinding-edge array that has extremely thin high integrity cutting edges.

► A duplex tank design that facilitates deposition of nickel ions and #14,000-mesh diamonds. ► Air supplied to stir settled diamond grit to improve depositional quality. ► Optimal current density of 2-ASD creates an ideal co-depositional layer and chip-pocket size. ► RC power conforms to the demand of minimal discharge energy. ► RWEDM technique can be used to fabricate a high-precision micro co-axial diamond wheel-tool array.