10--Research and development- Tunable Nano-oxides for Advanced Thermal Management

This contract action was accomplished using other than competitive procedures because there is only one responsible source due to a unique capability provided, and no other supplies or services will satisfy agency requirements (FAR 6.302-1). See posted J&A for further information. Tunable Nano-oxides for Advanced Thermal Management Applications 1.0 Objective: 1.1 The Analysis & Evaluation Technology Division, FPAT, METC of the US Army, RDECOM ARDEC, has an objective to study the thermal behavior of nanostructured tungsten trioxide (WO3) for potential application as a novel thermal barrier coating. The proposed work involves the development of nanostructured single crystalline tungsten trioxide nanowires. The proposed work will be applicable to a wide range of systems where components are exposed to extreme thermal conditions between -50 C and 70 C. For the Army, the major use of the thermal coating developed from nanostructured tungsten trioxide would be in the area of controlling localized temperatures of thermally sensitive electronics and other gun launched hardware. The Government's intent is to incorporate the knowledge gained from this study to advance current thermal management mechanisms of future and currently fielded munitions. 2.0 Scope/ Period of Performance: 2.1 The research project has a period of performance (POP) of 12 months after award with a goal to develop and characterize the morphology and crystal structure of nanostructured single crystalline tungsten trioxide nanowires produced via two methods: templating with electrospinning and core-shell blend electrospinning. 3.0 Background: 3.1 Gun launched systems are exposed to and expected to main functionality in a large thermal environmental range. Typical thermal requirements are -52 C to 71 C for storage and -41 C to 62 C for operations. Where possible, commercial off the shelf items are employed in launched systems. One limitation however is that some of the items or subcomponents may not be rated for the thermal ranges mentioned. Oscillators, IC, SAWs , and batteries are a few examples. Dynamic thermal coatings would alleviate potential high temperature failures of electronic components. Oxides such as yttria-stabilized zirconia (YSZ) have been employed as thermal barrier coatings, an adopted approach to protecting sensitive systems from high heat environments. In this capacity they perform as thermal insulators shielding the surface of the component from temperature fluctuations. They are traditionally employed for protection of gas turbine blades from wear due to thermal cycling. The drawback however is the high heat processing ( greater than 1000 C) and high temperature coating application (typically via thermal spray). We need a system that has comparable thermal properties but can be as effective at relatively lower temperatures: -50 C to 70 C. Bulk WO3 is commercially available, exists in stable reversible phases at low temperatures (between 50 C to 70 C), and has comparable thermal conductivity and coefficient of thermal expansion to YSZ. Nanostructured WO3 is anticipated to outperform bulk WO3 in terms of thermal behavior. Moreover, single crystalline structures of WO3 are considerably more stable, stronger and tunable than the polycrystalline counterpart which is what makes nanostructure single crystalline WO3 nanowires a promising candidate for this study. Moreover WO3 has never been studied as thermal coating. The proposed study will explore changes in structural and thermal properties of thermally cycled single crystalline nano WO3. The focus of this research will be on the triclinic and monoclinic phase transitions. The knowledge gained in the proposed work can be applied to improve the thermal performance of a wide range of gun launched components. 4.0 Applicable Documents: 4.1 ILIR FY2013 proposal: Tunable Nano-Oxides 5.0 Performance Requirements: 5.1 Goal: Develop and characterize the structural nature nanostructured single crystalline tungsten trioxide nanowires produced via two methods: templating with electrospinning and core-shell blend electrospinning 5.1.1 Tasks: The contractor shall: 5.1.1.1 Develop high yield single crystalline tungsten trioxide nanowire coatings 10 micrometers ( m) in thickness. 5.1.1.2 Perform X-Ray Diffraction and Transmission Electron Microscopy (under temperature as needed) of nanostructured tungsten trioxide nanowire coatings. 5.1.1.3 Advise and collaborate in identification of mechanisms for low temperature shielding applications 5.1.2 Deliverables: The contractor shall provide: 5.1.2.1 Single crystalline tungsten trioxide nanowire coatings greater than 10 micrometers ( m) in thickness for thermal analysis. 5.1.2.2 Results from diffraction and microscopy investigation (under temperature as needed). 5.1.2.3 Final Progress report (DI-MGMT-80555A)