Modelling and prediction of cutting temperature in the machining of H13 hard steel of multi-layer coated cutting tools

Abstract

The coating effect on the cutting temperature has long been a hot topic in understanding heat transfer mechanism in machining coated tools, and especially the multi-layer coated tools. For multi-layer coated tools, the coating structure, coating thickness and coating material will affect the cutting temperature of the tool. This paper is devoted to the cutting temperature in dry turning of H13 hardened steel with multi-layer coatings. New analytical models for estimating coating temperature and coating-substrate interface temperature were proposed. The multi-layer coating can be equivalent to mono-layer composite coating, which applies equivalent coating layer approach, and was developed to estimate the cutting temperature in turning by heat transfer model of mono-layer coated tool. The analyzed results were compared to appropriate experimental process data using thermocouples and FEM simulated data. The models were verified can accurate temperature under the same cutting conditions for two multi-layer coated tools.

Effects of tool coating materials and coating thickness on cutting temperature distribution with coated tools

“…The temperature on the other side of the tool opposite to the rake face is assumed to be ambient temperature, the coating thickness is d, and the coating tool thickness is L. The steady transfer analytical models established in ref. 17 (…”

“…The temperature on the other side of the tool opposite to the rake face is assumed to be ambient temperature, the coating thickness is d , and the coating tool thickness is L . The steady transfer analytical models established in ref 17 . are used to analyze, are as follows: $$\begin{equation} \def\eqcellsep{&}\begin{array}{l} T(x) = \dfrac{{{T_0} - {T_w}}}{{\dfrac{{{\lambda _s}}}{{{\lambda _c}}}(L - D) + d}}x + {T_w}\,,\,\,\,0 < x < d\\[25pt] T(x) = \dfrac{{({T_0} - {T_w})}}{{(L - d) + \dfrac{{{\lambda _s}}}{{{\lambda _c}}}}}x + \dfrac{{({T_w} - {T_0})}}{{(L - d) + \dfrac{{{\lambda _s}}}{{{\lambda _c}}}d}} + {T_0}\,,\,\,\,d < x < L. \end{array} \end{equation}$$…”