| In recent years, brittle materials such as Si and SiC wafer has a higher qualityand precision requirement with the development of information and opticstechnologies. Actually, abrasive processing is a precision machining technology cameinto being, based on solving problems of the loose abrasive lapping. The fixedultra-fine tools are usually made by traditional power metallurgy techniques. But, thedistribution of ultra-fine abrasives in the bond matrix is inhomogeneous due to theaggregation tendency of ultra-fine abrasives, affecting tool’s processing performance.However, ultra-fine powder can be dispersed in the liquid, and has uniform and stabledispersion by physical or chemical dispersion.In this paper, the EPD technology is proposed to fabricate the ultra-fine abrasivetool in order to solve the aggregation of ultra-fine abrasive in the bond matrix. Firstly,evenly and stably dispersed ethanol suspensions containing diamond powders andresin powder were prepared, supplemented by ultrasonic means or adding dispersant.Secondly, obtain a smooth and uniform coating by EPD. At last, the superhard film issintered. The abrication processes of the ultra-fine abrasive tools based on EPD andcuring sintering technique are investigated respectively. The machining performancesof new tools are evaluated by polishing SiC wafer. The main work of this thesis canbe summarized as follows:1. Build up the electrophoresis device platform for EPD experiments.2. Research and evaluate prepared electrophoretic suspension’s dispersion.3. Obtain smooth and uniform coatings by EPD. Research the influences ofsuspension concentration, applied voltage and deposition time on obtained coatings’quality, and adding ions on electrophoretic characteristics.4. Sinter EPD coatings. Research the influences of sintering temperature andholding time on sintered EPD coatings’ quality.5. Polish SiC wafer by prepared tool. Evaluate the tool’s performance from thesurface quality of workpiece. |
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