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The article of record as published may be found at https://doi.org/10.1017/S1431927618011352 This paper examines the deformation microstructures produced in metallic alloys by the cold gas dynamic spray (“cold spray”) process. CS deposition is a solid-state deposition process in which high velocity (300-1200 m/s), small (10-50 μm) metallic particles impact and adhere to a substrate. As the spray gun is rastered over the substrate surface a coating, and even a three-dimensional solid, can be produced. The CS process is now being used for corrosion protection, mitigation, and repair. [1] This process produces metallic materials under extreme conditions. The combination of small particle size and high impact velocity produces strain rates on the order of 106-109/s with average particle strains on the order of 50%. Understanding the deformation mechanisms and the microstructures that they produce is key to controlling the cold spray process and the mechanical properties of the deposited material. This talk will describe the use of electron microscopy and diffraction techniques, e.g. SEM, TEM, electron backscatter diffraction (EBSD), transmission kikuchi diffraction (TKD), and precession electron diffraction (PED), to visualize and to quantify plastic deformation in aluminium alloy and austenitic stainless steel materials. TDSI ONR |
