Prediction of Heat Transfer Behavior of Carbide Inserts With Embedded Heat Pipes for Dry Machining

Abstract

The temperature of a tool plays an important role in thermal distortion and the machined part’s dimensional accuracy, as well as in tool life in machining. The most significant factors in tool wear are temperature and the degree of chemical affinity between the tool and the workpiece. This research focuses on developing a clear understanding of the temperature distribution with cutting tool inserts embedded with heat pipes to eliminate the use of cutting fluids and reduce tool wealr in machining. A novel approach using the finite element analysis was developed to simulate the thermal behavior of a carbide cutting tool in three-dimensional dry machining. The carbide tools possess high material strengths at room temperature, but they cannot retain useful hardness at temperatures above 900°C (1700°F). Therefore, the reduction of tool wear typically requires maintaining the temperature of cutting tool inserts below some critical values. The particular temperature distribution depends on density, specific heat, thermal conductivity, shape and contact of the tool and heat pipe. Finite Element Analysis (FEA) shows that the temperature drops greatly at the tool-chip interface and that the heat flow to the tool is effectively removed when a heat pipe is embedded.