The diamond electroplating process is that diamond abrasives are electroplated on the metal base instead of the traditional pressed sintered method. It is not only low investment, low cost, but also avoids the oxidation of diamond grinding wheel at high temperature, ensuring the hardness and sharpness of the diamond.
In the process of electroplated diamond wheels and other diamond products, more than 90% of the plating is poorly bonded due to poor pre-plating treatment. Therefore, the most important thing is to do pretreatment of diamond electroplating process to improve the quality of plating.
Pre-plating treatments include oil removal, antitrust, etching, acid pickling, excitation cleaning, auxiliary electrode, and etc.
In order to improve the quality of the plating, make the pre-plating treatment as follows by analyzing and comparing the electroplating industry at home and abroad.
- Deburring: remove the burrs on the workpiece with sandpaper and hand file.
- Cleaning: Wash the workpiece with ethanol to remove the oil on the surface of the workpiece.
- Apply the insulating glue: After cleaning the workpiece, apply a layer of quick adhesive on the non-plated part to insulate that part.
- Scrub: In order to prevent the plating part from being coated with insulating glue, scrub the part again with a hand file or sandpaper, then wash.
- Chemical degreasing
Sodium hydroxide has strong saponification effect and reacts with animal and vegetable oils to form soluble soap and glycerin. Sodium dodecyl sulfate is a kind of surfactant that reduces the surface tension between liquid and workpiece under the effect of dodecyl hydrophobic group and sulfate hydrophilic group. It acts as a kind of alkali additive to speed up the decreasing. Sodium carbonate and sodium silicate are 2 kinds of buffers that can keep the pH value of the solutions unchanged. Put the workpiece into the above solutions and washed for about 30mins at 40 ° C to 60 ° C.
- Rinse with hot water and cold water: first, rinse with hot water, and then rinse with cold water to avoid degreasing solution into the acid solution.
- Acid pickling: to remove the oxide coating on the surface of the base.
- Wash with cold water: After acid cleaning, pick up the workpiece, wash it with cold water, and put into the electrochemical deoiling tank.
- Electrochemical degreasing
Put the workpiece in this solution, and switch on the power, and first cathode treat for 1min, and then anodizing for 3 mins. The current density is 10A/dm2, and the electrode is a stainless steel plate.
- Flushing: flush the workpiece after electrochemical degreasing.
- Anodizing: The base is mounted and insert the plating part into the solution. The cathode is a lead plate, and anodize is base. The current density is 25A/dm2, and power on time is 3mins.
- Flush into the bath: After flushing, the base that is finished anodizing put into the plating bath for electroplating.
In the actual diamond electroplating process, it should be strictly pre-treated in order to obtain high-quality electroplated diamond tools.