Precision machining of sintered zirconia ceramics is expected for various applications such as dental prostheses or artificial femoral heads. However, machining of zirconia is a major challenge because of its high hardness. We have found that the bending strength and fracture toughness of this material decrease with an increase in temperature. To use this characteristic, we propose a high-speed milling process with a cutting speed of more than 500 m/min because high-cutting speed can generate a large amount of heat during cutting. According to the results of trials, precision machining of the surface was possible with a cutting speed of 670 m/min. Moreover, the amount of flank wear was decreased by the high-speed milling. These results confirmed the possibility of precision cutting of sintered zirconia ceramics.

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