Determination of thermal material properties for the numerical simulation of cutting processes

Thermal properties of machined materials, which depend significantly on the change in cutting temperature, have a considerable effect on thermal machining characteristics. Therefore, the thermal properties used for the numerical simulation of the cutting process should be determined depending on the cutting temperature. To determine the thermal properties of the machined materials, a methodology and a software-implemented algorithm were developed for their calculation. This methodology is based on analytical models for the determination of tangential stress in the primary cutting zone. Based on this stress and experimentally or analytically determined cutting temperatures, thermal properties of the machined material were calculated, namely the coefficient of the heat capacity as well as the coefficient of thermal conductivity. Three variants were provided for determining the tangential stress: based on the yield stress calculated using the Johnson-Cook constitutive equation, based on the experimentally determined cutting and thrust forces as well as by directly calculating the tangential stress. The thermal properties were determined using the example of three different materials: AISI 1045 and AISI 4140 steel as well as Ti10V2Fe3Al titanium alloy (Ti-1023). With the developed FE cutting model, the deviation between experimental and simulated temperature values ranged from approx. 7.5 to 14.4%.

Automated summary

The study focused on the impact of thermal properties of machined materials on thermal machining characteristics, developing a methodology based on the determination of tangential stress. Thermal properties of the materials were calculated based on this stress and cutting temperature, with the developed FE cutting model achieving a deviation between experimental and simulated temperature values ranging from approximately 7.5% to 14.4%.