Vehicle Technology Directorate, Vehicle Technology Directorate, Propulsion Division
||Abredeen Proving Ground, MD 210055066
ARL conducts basic and applied research involving propulsion materials. Specialized engine and drivetrain materials require continual improvements to expand performance of aerospace propulsion systems. This research is a critical part of on-going mission programs toward developing advanced propulsion materials for current and future Army vehicles. ARL propulsion materials research focuses on achieving several Army platform-specific goals. A research thrust within the Army is to develop technologies supporting “maintenance-free” rotorcraft, as an integral part of the long-term Future Vertical Lift Program. For propulsion materials, this refers to wear-resistant drive train surfaces (highly-loaded, infinite-life gears) and thermomechanical fatigue-resistant engine materials. Development of theoretical methods to assess the process-structure-property relationship in complex materials, such as ceramic matrix composites, fatigue resistant fiber metal laminates, and/or engineered metal alloys, is required to achieve this goal. The Army’s push toward damage-tolerant structures and condition-based maintenance requires high fidelity material state awareness.
The engineering technologies to evaluate mechanical, thermal, and chemical properties with high spatial fidelity of propulsion materials at elevated temperatures and across length scales are in their infancy. High-temperature sensors, thermal and chemical damage quantification, and life cycle analysis including accurate and reliable material life prediction are critical enabling technologies for future systems. Lastly, material design under uncertainty is necessary to achieve performance metrics for future vehicles operating in a wide range of conditions. Our focus areas include high-temperature materials and sensing for engine and drivetrain (power transmission) component, bulk materials analysis and characterization for ceramic matrix composites, high-temperature polymer matrix, metal alloys, engineered design high-temperature materials, engine health monitoring, and thermal and environmental barrier coatings. Possible propulsion materials research topics include:
(1) Propulsion Material Characterization—quantifying the evolution of fatigue damage (thermomechanical) at the microscales of a high-temperature ceramic matrix composite material system, scanning acoustic microscopy (SAM), X-ray microtomography, and microstructure evolution; studying the relationship between initiation of damage and exposure to oxidation mechanisms and transport phenomena in high-temperature polymer matrix composites; and creating non-averaged microstructural descriptors.
(2) Modeling and Simulation—Predicting the thermomechanical behavior of composite materials based on microstructural data and constitutive models via nonlocal micromechanics; simulating manufacturing processes to predict residual stresses, residual micro-cracking, and quantifying variation in material structure via process modeling.
(3) Materials by Design—designing and developing new bulk high-temperature materials that can sustain 1500o C or higher temperature, developing new thermal barrier and environment barrier coatings that would enable materials to survive higher temperature and extreme environmental erosion without the requirement of active cooling, and developing new composite gear materials that would enable heat transfer and are wear resistant.
Liu KC, Ghoshal A: Composites Part B: Engineering 57: 56, 2014
Ghoshal A, Kim HS, Le DD: Sensor Review 32(1): 66, 2012
Propulsion materials; Material characterization; Rotorcraft turboshaft gas turbine engine; Power transmission materials; Damage precursors; Rotorcraft engine; Aircraft; Propulsion; Engineered materials;