Objective

This three year project aims to develop novel sandphobic coatings for thermal/environmental protection of gas turbine engine (GTE) components operating at high temperatures, which will improve the sustainment and performance of military air and ground vehicle engines under all weather conditions and operational constraints. In particular, the proposed coatings will prevent the buildup of deleterious calcia-magnesia-alumino-silicates (CMAS) on engine components.

Technical Approach

This project focuses on the following:

  1. Development of uncertainty-based multiphase computational flow framework (multi-UQ) to simulate highly non-linear turbulent flow transport, fluid-solid energy transfer, and deposition/build-up characteristics of CMAS in thermo-fluid environments relevant to GTE components.
  2. Identify and rank the governing parameters for CMAS deposition, buildup and melt infiltration in the thermal/environmental barrier coatings (T/EBC) layers via computational and experimental efforts.
  3. Engineered design of particulate-resistant and CMAS-phobic high temperature thermal/environmental barrier coatings on flat material specimens, curved aero-shells and turbine components like rotor blade, stator, and shroud for both SiC/SiC ceramic matrix composite (CMC) material and Ni based superalloys based substrates as informed by Objectives 1 and 2.
  4. Characterization of the mechanical properties of high temperature coating materials through thermomechanical fatigue and creep testing; in addition, coated substrates will be exposed to high-temperature particulates in Army Research Lab's (ARL’s) modified ablation rig.
  5. Evaluation of proposed coating materials in ARL’s hot particulate ingestion rig (HPIR), which provides engine relevant temperature (up to 1650 °C) and flow velocity conditions (up to Mach = 0.8); thermal and sand non-adherence performance of the T/EBCs will be compared to the current industry standard: yttria-stabilized zirconia (YSZ).
  6. Establishment of the protocols, on a go/no go basis, necessary for an initial assessment of human health and environmental impacts of the ingredients, formulations, and by-products.
  7. Establishment of a baseline lifecycle framework, which identifies the necessary elements of a lifecycle inventory; this framework shall identify those elements that are already known, those that will be investigated during the course of the project, and those that are beyond the development phase of the project work.

Benefits

The project sandphobic T/EBC technology will be required to seamlessly integrate into new engines and retrofit into existing air, ship and ground vehicle engines. For military purposes, sand-phobic coated substrates will be expected to survive gas temperatures ranging from 1100 to 1500 °C during sand ingestion engine tests. Through implementation of this technology into current and future aero-engines, the Department of Defense would benefit from highly reliable engines that can meet or exceed their mean time between overhaul even while operating in extreme, particle-laden environments. In addition to reducing the current logistical burden and lowering overall life-cycle costs, aircraft equipped with this technology in their engines would have higher operational availability.