Effects of coolant on temperature distribution in metal machining

AbstractThe effects of coolant on tool temperature in metal turning operations were studied both experimentally and theoretically. Values for the coefficient of heat transfer from the tool to the coolant were obtained. Experimentally, a medium carbon steel was turned at a feed rate of 0·254 mm rev −1, at cutting speeds of 33–61 m min−1, with high speed steel tools and water based coolant. Tool temperatures estimated from structural changes in the tool were compared with values calculated by finite element analysis. Heat transfer coefficients from tool to coolant between 103 and 5 × 103 W m2K−1, depending on coolant flow rate, best match theory and experiment. Further, it is shown by the calculations that tool temperatures are particularly sensitive to changes in heat transfer coefficient between 103 and 104 W m−2K−1. This is the range in which coefficients are to be found in practice, explaining the critical nature of cutting fluid formulation, supply rate, and direction of application in those operations...