Prediction of Cutting Temperature Distribution in Transient Heat Conduction of Monolayer Coated Tools Based on Non-Fourier Heat Conduction during Machining of H13 Hard Steel

Abstract— A predictive model for transient heat conduction during the machining of hard steel based on non-Fourier heat conduction was developed. A mono layer cutting tool coated with TiN coating of carbide substrate was used with 2μm thickness. The work piece material used was a cylindrical bar of H13 hard steel, 300mm length and 70mm external diameter. The cutting speed range was 35.9-244.4m/min, feed rate of 0.2m/rev and depth of cut of 0.2mm. A developed wireless temperature measurement was employed with the thermocouple sensor embedded in the turning tool. The developed model is simplified and contains hypothetical conditions. An infinitesimal convective heat conduction coefficient makes the boundary to be an adiabatic or thermostatic boundary. During machining, the coated tool and workpiece material's heat dissipation are neglected. Prediction was done and compared between the Fourier heat conduction model and the non-Fourier heat conduction to reveal the non-Fourier model effect on transient heat conduction. Predictions by the two models are considerably dissimilar with 77.10C difference at 0.1s cutting time. The predicted temperature difference between the two models when the cutting duration is 10 s is 4.90C. The temperature tends to stabilize when the cutting time is sufficient and heat conduction reaches its steady state. From the results, it can be concluded that the transient heat conduction model is more suitable for the intensity transient-state in the process of cutting heat conduction. The prediction error is less than 12%, which is acceptable for industrial applications and proves the efficiency of the developed model.