Optimization of geometry parameters for ceramic cutting tools in intermittent turning of hardened steel

For the purpose of improving the ceramic cutting tool lives in intermittent hard turning, investigations on optimization of tool geometry parameters were conducted in the present study. The initial damage of the ceramic cutting tool was determined based on damage mechanics. The initial damage was more sensitive to the changes of porosity when it was relatively low. The stress distribution of the tool body was obtained using finite element simulation. The initial damage of the cutting tool and the tool stress were integrated on the basis of the concept of damage equivalent stress. The evolutions of the maximum value of damage equivalent stress on the tool body were acquired for different cutting length ratios and different combinations of tool geometry parameters. The highest value of damage equivalent stress in one cutting cycle was proposed as a new indicator for optimization of tool geometry parameters. The contribution order of tool geometry parameters for the indicator was corner radius, cutting edge angle and rake angle. This order stayed the same at different cutting length ratios. The optimization method for ceramic tool geometry parameters was proposed and it was validated through intermittent turning tests. [Display omitted] •Tool material damage is defined as the relative surfacic fraction of microdefects.•The initial damage of the ceramic tool is obtained as 0.0068 using damage mechanics.•The highest damage equivalent stress is a new indicator for tool geometry optimization.•The proposed optimization method well predicts the optimum tool geometry.