Ti-coated diamond micro-powder for the manufacture of the electroplated diamond wire saw

The electroplated diamond wire saw has been widely used in the production of semiconductors, photovoltaic devices, etc. Composite electroplating is an important process in the production of electroplated diamond wire saws. The utilization of nickel (Ni)-coated diamonds is a widely adopted approach to enhance the efficiency of the composite electroplating process employed in the manufacturing of wire saws. However, the pristine diamond does not chemically react with Ni, and the interfacial bonding strength between the Ni coating and the diamond is relatively weak. This frequently results in the detachment of diamonds from the Ni coating during the cutting process. To solve this problem, titanium (Ti)-coated diamonds were used in the preparation of wire saws. We had specially developed a vacuum slow evaporation technology to produce diamond micro-powder (8 μm) with uniform conductive Ti coatings that were firmly bonded with diamond through the interfacial product TiC. A series of electrochemical test results were used to demonstrate the effect of Ti coating on the composite electroplating process. The linear scanning voltammetry curves showed that the addition of Ti-coated diamond shifted the overpotential of composite electroplating in a positive direction, so it promoted the electrodeposition reaction more than diamond powder. The electrochemical impedance spectroscopy revealed that the conductive Ti-coated diamond reduced the charge transfer resistance during composite electroplating. The Ti-coated diamond micro-powder was completely enveloped by an electroplated Ni layer, and TiC formed between the Ti coating and the diamond provided a stronger interfacial bonding force compared to that of the Ni-coated diamond micro-powder. After cutting, the Ti-coated diamond was found not to fall off the wire saw. The use of Ti-coated diamond micro-powder as an abrasive will significantly improve the product quality of mass-produced electroplating diamond wire saws.