Experimental research on the dynamic characteristics of the cutting temperature in the process of high-speed milling

Abstract

The cutting temperature is a key factor which directly affects cutting tool wear, workpiece surface integrity and machining precision in the high speed machining (HSM) process. The purpose of this paper is to present an inverse heat-transfer model considering three-dimensional transient heat conduction to calculate the heat flux and the temperature distribution on the tool–workpiece interface in the high speed milling process. The model was set up by a finite element method based on Beck’s inverse heat-conduction theory and was verified by numerical simulations and a series of experiments which aimed to obtain the surface temperature data of a thin-walled workpiece with the aid of an infrared thermometer and the tool–workpiece interface temperature by an embedded artificial thermocouple. The dynamic characteristics of the cutting temperature in high-speed milling aluminum alloy were studied systematically. The numerical simulation results revealed that there was a close agreement between the calculated temperature value and the measured temperature value of the cutting interface in high-speed milling of aluminum alloy. The inverse heat-conduction method can be used to estimate the heat flux flowing into the workpiece and the temperature distribution on the tool–workpiece interface. Using the infrared thermometer as a remote sensor can solve the problem of measuring the temperature in high-speed milling and also it can be used as an approach to reveal the cutting mechanism of high-speed milling. There exists a critical cutting speed in the high-speed milling aluminum alloy. The value of this critical speed will be different for the different cutting conditions. Constant feed per tooth must be kept in high-speed milling to efficiently suppress excessive heat generation while obtaining a high material removal rate, especially for machining difficult to-cut materials with a thin-wall construction. The average tool–workpiece interface temperature is influenced by the thickness of the workpiece. The related temperature distributions will be very beneficial to the optimal construction design for the thin-wall parts used in the aeronautics and astronautics as well as die and mold industries.