Thin film microstructure and thermal transport simulation using 3D-films

Simulations of the flow of heat through porous thin films by the three-dime nsional microstructural thin film simulation framework 3D-Films are discuss ed in this paper. For each simulation, the film structures are generated by the thin film growth model 3D-Films and then used to generate a finite dif ference based thermal model by the program 3D-Films/Thermal. This program c reates a block based data structure using a 3D quadtree mesh and subsequent ly solves for the steady state heat Row through the film structure. In this paper the film growth and thermal models are used to analyze and suggest o ptimization of porous thermal barrier coatings produced by glancing angle d eposition techniques. The paper also deals with the determination of the ac curacy and efficiency of the thermal model. Studies on the effect of reduci ng the resolution of the simulated film for less memory intensive thermal s imulations are presented, indicating that a reduction of the resolution by a factor of 3 and the number of solution variables by as much as a factor o f 27 is feasible. The simulations Of ZrO2 thermal barriers are compared to experimental results with a relatively close match being obtained. Finally, the simulator is used to analyze the effectiveness of a number of potentia l thermal barrier structures produced by glancing angle deposition techniqu es. These results suggest that the most effective thermal barrier film micr ostructures will be porous films consisting of slanted posts or large pitch helices. (C) 2001 Elsevier Science B.V. Ah rights reserved.