Studies on cutting temperature by dimensional analysis (2nd report: Influence of thermal properties of workpiece and tool materials)

Abstract

An evaluating equation to present the influence of thermal properties of workpiece and cutting tool on the cutting temperature is derived by the dimensional analysis. Turning experiments are carried out in order to confirm the propriety of the equation. Ti-6Al-4V, Inconel718, SUS304, S50C, 6/4 Brass, Aluminum and AZ80 are used as workpiece materials, and Al2O3, Si3N4, Cemented Carbide, CBN and Bidemics as tool materials. Cutting temperature is measured by two-color pyrometer with an optical fiber which is developed by the authors. The phenomenon of chip combustion is used to estimate the cutting temperature in turning of Ti-6Al-4V. As a result, the equation derived in this paper is useful and convenient to evaluate the overall influence of cutting conditions, thermal properties of workpiece materials and those of tool materials on the cutting temperature. The equation consists of the factors of cutting speed, depth of cut, feed rate, specific cutting energy, thermal diffusivity of workpiece and that of cutting tool. Moreover, experimental result suggests that the specific cutting energy of the workpiece material is estimated using only its volumetric specific heat and melting point.

Keywords

• dimensional analysis
• cutting temperature
• cutting speed
• feed rate
• depth of cut
• specific cutting energy
• thermal diffusivity
• volumetric specific heat
• thermal conductivity
• melting point
• two-color pyrometer