Induction heating in estimation of thermal properties of conductive materials

Abstract

Purpose The purpose of the research was to develop a method for the determination of temperature characteristics of thermal diffusivity and specific heat on a single and the same stand, powered from an inverter for induction heating. Determination of the thermal diffusivity has been based on the idea of the pulse method. Searched solutions allowed to reduce inaccuracy of the pulse method when such an unusual source of pulse of energy is used. Design/methodology/approach Coupled electromagnetic and thermal calculations were carried out to verify proposed methods for estimating thermal properties of an induction heated charge. Presented methods were applied into a real laboratory stand and they were examined experimentally. Findings Achieved results of calculations allow to estimate thermal properties of the induction heated charge with 2 and 5 per cent of uncertainty, respectively, for heat capacity and thermal diffusivity. It gives possibility to use results as an input for further proceedings connected with estimation of electrical parameters in a more complex system. Practical implications Presented methods of estimating thermal properties of the induction heated charge were verified experimentally on a dedicated laboratory stand. It gives a practical possibility to implement previously established assumptions and examine them. This is a significant step toward the construction of an easy-to-use device for a comprehensive determination of material parameters of metals directly in the heat treatment plant. Originality/value This study presents a trial of implementation of induction heating as a source of energy in the impulse method for estimation of thermal properties of the material. Additionally, it presents a process of improving results achieved with the flash methods which were presented in previous papers. The method of estimation of specific heat which uses induction heating as the heat source was presented too.