The Investigation Of Synthetic Diamond Surface Plating And Application

As we all know, plating on the surface of synthetic diamond can improve the properties of resin bond diamond wheel. This paper studies the effects on the morphology, particle size, toughness and compressive strength by changing the plating current and the diamond size; at the same time compares morphology characteristics and composition of the vacuum titanium plating layer and chemical nickel plating layer on diamond surface; uses different diamonds with different plating conditions as abrasives to make grinding wheels; studies the suppression process of resin bond diamond grinding wheel to find the best process condition; by detecting morphology of grinding wheel, composition, parallel, hardness, wear resistance, explores the performance of the diamond grinding wheel affected by different coating conditions.After studying the problems of synthetic diamond surface plating and application, we get following results.1. By studying the effect of electroplate current and particle on the performance of Ni-plating diamond, we find that:(1) when the electroplating process and the composition of plating are in a certain condition, as the electroplate current increases, the plating layer of diamond surface will be more uniform, dense, less happening of skipping plate, at the same time, plating velocity, impact toughness and compressive strength all increase. Electroplating current can affect the bath temperature, while the bath temperature determines the density of the coating. The microscopic strain of nickel plating layer becomes the smallest and coating density achieves the maximum when the bath temperature is 50℃.(2)With the size of diamond particle increases, the plating speed increases, as well as the growth rate of average size and compressive strength of nickel plated diamond particle.2. The phenomenon of skipping plate is obvious if we use vacuum titanium plating technology only. The plating layer will be uniform and dense if chemical plating is applied after vacuum titanium plating.3. It can be obtained from the orthogonal experiment that the best process conditions of making resin bond diamond grinding wheel are: the pressing temperature 185℃, mixing materials time 1 hour, the pressure 19 Mpa, pressure maintaining time 50 minutes and grinding wheel thickness 0.8 to 1 mm. Diamond is completely covered by binding agent in thermoforming wheel and will be bared in the grinding process gradually.The influence of various factors on the resin bonded grinding wheel are summarized as follows:(1) The temperature mainly affects the hardness of the wheel and the hardening temperature of phenolic resin bonded abrasives grinding wheel is controlled between 180 to 190 ℃for the best;(2) Mixing time mainly affects the hardness of the wheel. The grinding wheel can achieve certain hardness when the mixing time reaches an hour;(3) Maintain time and pressure are not the main factors affect the wheel performances in the various factors. The performances of the wheels reach the best when the pressure is 19 Mpa and maintain time 50 minutes under the process conditions of this study;(4) Thickness of the grinding wheel mainly affects the parallelism. Specifically, if we make the finished product’s thickness to be 0.8 to 1 mm, the parallelism will be better.4. After the process of metal plating, the diamond surface is full of Ni splinter which is benefit to mechanically fit with binding agent and make it not easy to fall off during the grinding process, thus the performance of the diamond grinding wheels can be significantly improved; when the electro-nickel plating process and weight-gaining rate are both similar, abrasive resistance of grinding material made by vacuum evaporation of titanium coating process is better; when we apply high current but short time plating process in the making of abrasive nickel plating layer, the plating layer is denser and therefore abrasive resistance of grinding wheel better; the weight gain rate of layer affects the growth status of Ni splinter coated on diamond surface which include making the weight gain rate more faster, gripping force of binders to abrasive particles weaker, resulting in abrasive particles easily falling off, and reducing the abrasive resistance of grinding wheel as a result.