Evaluation of Effective Thermal Conductivity for Mineral Cast Structural Materials Using Steady-State and Transient Methods

Thermal conductivity is a thermophysical property that represents the rate at which heat energy can be transported through the material. For any alternate material chosen for machine tool structures, the study of its thermal characteristics is imminent. Thermal conductivity is one major characteristic to be analysed. Mineral cast structures made of epoxy-granite are found to exhibit good mechanical properties, such as high stiffness and damping ratio. The material also has lesser weight, compared to conventional materials used for machine tool structures. Hence, these materials are emerging as an alternate to conventional cast iron machine tool structures. This study attempts to determine the effective thermal conductivity of epoxy granite material using steady-state and transient plane source (TPS) methods. The results obtained using the experimental methods are compared with geometrical models and the suitability of the methods is evaluated. It is observed that both methods are suitable for measuring effective thermal conductivity of two-phase materials. Compared to TPS method, the steady-state method is a slow and material-consuming technique but provides more accurate results. The effective thermal conductivity of the developed material is compared with some commercial polymer composites and observed that the developed material has greater thermal conductivity.