To enhance the friction and wear performance of cemented carbide, textured microholes were machined on micro Electron Discharge Machining (EDM) on the tool rake face, and Calcium Fluoride (CaF2) powders were burnished into the microholes. The friction and wear characteristics of the microhole-textured tool filled with CaF2 were investigated using sliding friction tests and dry cutting tests. Results exhibited that the working temperature could affect the tribological performance of the microhole-textured tool filled with CaF2 due to the temperature-sensitive nature of CaF2. There is no obvious lubrication effect for the textured tool filled with CaF2 at room temperature, while it was shown to be more effective in improving tribological property at a cutting speed of higher than 100 m/min with a corresponding to cutting temperature of 450 °C. The possible mechanisms for the microhole-textured tool filled with CaF2 were discussed and established.
29 May 2017 in The International Journal of Advanced Manufacturing Technology
To expand the industrial application of cemented carbide, micro-EDM was utilized to machine microhole-textures on the carbide surface; graphite powder was burnished into the textured microholes. The tribological properties of the microhole-textured tool combined with graphite were investigated and compared with the conventional one by carrying out reciprocating sliding friction tests and dry machining tests. Results exhibited that the microhole-textured tool combined with graphite possessed a much lower friction coefficient than that of the conventional one in sliding tests. The cutting forces, average friction coefficient at the tool–chip interface, and rake face wear of the textured tool were reduced, and the workpiece surface quality was also slightly improved. The worn regions of carbide specimen were examined and studied, and the possible effect mechanisms for the enhancement of friction and wear properties mainly consisted of the formation of uneven graphite film by friction extrusion, reduction of actual contact length, entrapment of wear debris and supply of graphite lubricant.