A modelling approach for the sintering kinetics of porous ceramics, based on principles of free energy minimisation, has recently been published by Hutchinson et al1. This model is adapted in the current work for the pore geometry exhibited by plasma spray coatings and is applied to zirconia-based TBCs. Predictions are made for the evolution of coating thickness, porosity level and specific (interconnected) surface area, as a function of sintering time and temperature. These predictions are compared with experimental data obtained by dilatometry, densitometry and BET surface area measurements. Discrepancies betwwen predictions and experimental data are considered in terms of the simplifications incorporated in the model and other possible complications. The model is also used to predict the evolution of the contact area between overlying splats. This is in turn related to the through-thickness thermal thermal conductivity, via a previously developed analytical model2. It is shown that measured thermal conductivity data are broadly consistent with predictions from this model, using contact area predictions obtained from the sintering model. It is therefore concluded that both of these models are able to capture the main features of the sintering process and the heat transfer mechanisms operative in these coatings. However, there are still areas of uncertainty, particularly relating to the contribution of lattice diffusion, the effects of various impurities and alloying additions in the zirconia on the diffusional characteristics and the development of residual stresses from in-plane contraction. 1. Hutchinson RG, Fleck NA, Cocks ACF, A Sintering Model for Thermal Barrier Coatings, Acta Mater., 54 (2006) 1297-1306. 2. Golosnoy, IO, Tsipas, SA and Clyne, TW, An Analytical Model For Simulation Of Heat Flow In Plasma Sprayed Thermal Barrier Coating, J. Thermal Spray Techn., 14 (2005) 205-214.