AVS 52nd International Symposium
    Advanced Surface Engineering Monday Sessions
       Session SE-MoM

Paper SE-MoM7
Optimization of Multilayer Wear-resistant Thin Films Using Finite Element Analysis

Monday, October 31, 2005, 10:20 am, Room 201

Session: Nanocomposites and Coatings with Enhanced Thermal Stability
Presenter: R.K. Lakkaraju, University of Nebraska
Authors: R.K. Lakkaraju, University of Nebraska
F. Bobaru, University of Nebraska
S.L. Rohde, University of Nebraska
Correspondent: Click to Email
Extensive research has been carried out by researchers on the growth and characterization of multilayer protective coatings, but the design of these coatings still remains largely empirical. In this regard, recent progress has been made in developing a design approach for optimizing multilayer coating structure before deposition which would help in saving time and material. In pursuit of optimal design, finite element analysis using a plane strain, hertzian contact model was developed to investigate the stress/strain behavior within the layers of the system. The present study looks to find optimal thicknesses of individual layers in the multi-layer coating-substrate system. First test case is a multiobjective optimization of a multilayer system performed by minimizing the strain discontinuities at the coating/substrate interface and the stresses developed in top layer, under combined normal and tangential load conditions. Another option is a single objective optimization (minimizing the strain discontinuity) by constraining the stress values below yield strength. We discuss the use and efficiency of optimization algorithms such as genetic algorithm and gradient based routines used in the present work, and the preliminary results are compared to pin-on-disk wear results of empirically designed coatings.