The industrial requirements for higher productivity along with the increasingly stringent protocols for sustainable machining have directed focus towards the process optimisation. The aim is to enhance productivity while maintaining surface quality and dimensional tolerances within the standard specifications. A reliable tool wear prediction is thus essential for determination of the productive range of cutting conditions. This requires an accurate estimation of tool temperature as it dictates the rate of thermally induced wear mechanisms like oxidation or dissolution-diffusion.

Available experimental methods to measure the temperature at the tool-chip interface are costly and face many limitations making them fallible in many cases [1], whereas Finite Element (FE) simulation of chip formation to obtain tool temperature is not only time-intensive but also prone to error. Semi-analytical temperature models have been proposed as an alternative to overcome these limitations.

This study aims to enhance the predictability of semi-analytical temperature models proposed by Komanduri and Hou [2] and Moufki et al. [3]. A novel approach is presented here to obtain the variable heat flux along the tool-chip contact length by taking into account the amount of heat generated in sticking and sliding zones. The variable heat flux is then used in the context of these two models to predict the interface temperature when machining C45 and C50 plain carbon steels by uncoated tools under dry conditions. A comparative analysis is then performed to assess the effect of the variable heat flux on the calculated maximum interface temperature and its location on the tool rake face. It is determined that the incorporation of the variable heat flux does not substantially change the value of the maximum interface temperature, as shown in Figure 1a. However, variable heat flux does lead to a considerably better prediction of its location as the estimated temperature profiles better coincide with the deepest crater wear distance, see Figure 1b. The limitations and advantages of extended semi-analytical models and the possibilities for future developments are also presented.

References

[1] J. Ning; S.Y. Liang; The International Journal of Advanced Manufacturing Technology, 2019, 102, 3109-3119.

[2] R. Komanduri; Z.B. Hou; International Journal of Mechanical Sciences, 2001, 43, 89-107.

[3] A. Moufki; A. Molinari; D. Dudzinski; Journal of the Mechanics and Physics of Solids, 1998, 46, 2103-2138.