You are here

Design Framework for Optimized Multifunctional Coatings

Description:

TECHNOLOGY AREA(S): Air Platform 

OBJECTIVE: Develop a multiphysics-based optimization methodology to design multifunctional materials, including high temperature special technology coatings for use in engine/aircraft high temperature exhaust regions. 

DESCRIPTION: There is a desire to improve the design methods for specialty, multifunctional coatings. Such improvements will decrease the time to insertion of new material systems while also ensuring thermal, mechanical, and electrical performance and reliability. The coating and substrate need to be designed across multiple scales and as an interactive system. The models should consider the microstructures necessary to achieve the desired multiphysics response while also ensuring structural integrity under extreme loadings. The design methods must integrate with living models that account for predicted environmental factors, such as high temperatures, fast temperature rates, environmental exposure, dynamic and static strain effects, and vibrational effects. In addition, the model should be able to analyze and account for the robustness of the optimized coating given potential manufacturing variabilities. For instance, the effects of the residual stresses should be considered as well as the effects of defects (e.g. porosity) introduced during the manufacturing process. Currently there are models that are capable of addressing many individual aspects of the problem, however, current state of the art coating models do not provide a comprehensive, multiscale consideration of the microstructure, effective material properties, and structural response. The method should be able to investigate a large number of possible microstructures efficiently while eliminating solutions that do not meet the desired multiphysics responses. In addition, the method should investigate spatially-varying solutions that are a function of the gradients in loading conditions while still ensuring manufacturability. As such, the design and optimization methods should be able to provide guidance on the material and/or manufacturing tolerances that must be met to meet the requirements. It may be possible to leverage processing-structure-property information, experimental data, and models developed for thermal barrier coating systems; however, special technology coatings are more complex, containing multiple phases as well as significant porosity, which complicates analysis. The material coating(s) to be used in the development and validation of the modeling tools should be surrogate materials, identified with assistance from the Government. The government will not provide material samples or technical data. The method is intended to be utilized to develop more durable material coating for current platforms, in both initial and repair environments. The methods developed will have applicability to military and commercial applications. These alternative coatings will be transitioned to the appropriate platform of interest based on their performance and availability of funding. 

PHASE I: Identify and develop coating design modeling methods: Develop multi-scale approach to modeling coatings that can enforce required material properties and integrate with the predicted structural response. Verify that the method is stable and can account for the physics present in the system. Demonstrate model’s predictive capability and document the results. 

PHASE II: Perform design of coating systems and compare to experimental data, as available. Expand method to introduce topological optimization based on gradients in thermomechanical loading. Demonstrate ability to perform a parametric optimization of the microstructure. Demonstrate model’s ability to provide material and manufacturing tolerances. Verify that the method is accounts for the physics present in the system. Demonstrate model’s predictive capability and document the results. 

PHASE III: Further expand the design methods to include microscale features and nanoparticle loadings: Demonstrate ability to predict response to multiphysics stimuli in new environments and for new material systems. Verify that the model is stable and represents physics present in the system. 

REFERENCES: 

1: The Ceramic Society of Japan, Advanced Ceramic Technologies & Products, Y. Imanaka, Ed. (Springer, Tokyo, Japan, 2012) chap 13.

2:  S. Bose, High Temperature Coatings (Butterworth-Heinemann, Burlington, MA, 2007).

3: Bendsoe, Martin Philip, and Ole Sigmund. Topology optimization: theory, methods, and applications. Springer Science & Business Media, 2013.

4:  Sigmund, Ole, and Salvatore Torquato. "Design of materials with extreme thermal expansion using a three-phase topology optimization method." Journal of the Mechanics and Physics of Solids 45.6 (1997): 1037-1067.

KEYWORDS: Design, High Temperature Coatings, Multiphysics, Topology Optimization 

CONTACT(S): 

George Jefferson 

(937) 255-1307 

george.jefferson.1@us.af.mil 

US Flag An Official Website of the United States Government