After spraying, the size of the sprayed coating is not accurate, and the surface is also rough. In the case of requiring accurate geometric dimensions and smooth surface of the coating, it can only be achieved by finishing. Finishing is usually done by mechanical cutting or (and) grinding. The mechanical processing of the coating is not completely different from the processing of the ordinary overall material. Due to the particularity of the coating structure, it has the following characteristics. 1. The bonding strength of the coating is limited, especially the weak parts at the edge cannot withstand excessive cutting stress, and it is easy to cause the coating to peel off or individual particles to come off due to improper machining. 2. Generally, the coating has low toughness, high brittleness, and is not easy to cut. 3. The wear-resistant coating has high hardness (some coatings also contain hard particles), poor thermal conductivity, easy tool wear and high cutting edge temperature. 4. The coating is generally thin, and the machining allowance is not large. If the machining is not careful, it is easy to cause the size to be out of tolerance. Due to the above characteristics, special attention should be paid to selecting suitable processing methods, suitable tool materials and tool geometric parameters, determining the correct processing procedures and processes, and using suitable cutting fluids during machining.
