A new data reduction method for pulse diffusivity measurements on coated samples

• Published in: Computational materials science 2010-11, Vol.50 (1), p.77-82
• Main Authors: Chen, Liguo, Limarga, Andi M., Clarke, David R.
• Format: Article
• Language: English
• Subjects: Coated sample; Computer simulation; Condensed matter: structure, mechanical and thermal properties; Data reduction; Diffusivity; Exact sciences and technology; Heat transfer; Mathematical analysis; Mathematical models; Nonelectronic thermal conduction and heat-pulse propagation in solids; thermal waves; Numerical method; Physics; Thermal contact resistance; Thermal diffusivity; Thermal resistance; Transport properties of condensed matter (nonelectronic)
• ISSN: 0927-0256; 1879-0801
• DOI: 10.1016/j.commatsci.2010.07.009

A new method, based on numerical solutions of the heat conduction equation, is presented for reducing flash diffusivity data to determine the diffusivity of a coating on a substrate of known thermal properties. Measurements are performed with a conventional thermal flash apparatus and the calculated curve from the numerical simulations is fitted to the measured temperature–time curve, the “thermogram”. The current work is a natural extension of previous work on single layer, homogeneous samples [1]. The main advantage of this new data reduction method, which incorporates nonlinear least-squares regression, is that both the thermal diffusivity of the coating and the thermal contact resistance can be determined. When the thermal contact resistance is small, the solution automatically converges to the perfect thermal contact case. To demonstrate its efficacy, the method is first implemented by analyzing a group of simulated data and then applied to a set of experimental data obtained from three different bilayer samples.