Superelastic Shape Memory Alloy for seal Applications produced by low pressure plasma spraying

Recent developments in low pressure plasma spraying (LPPS) show that shape memory alloy (SMA) materials can be successfully created with the plasma spraying process. Thin, near net shape foils (100um thick) were produced using the LPPS method. Using this process no significant change of their transition temperatures (max 5C) in the sprayed and heat treated condition could be found. Tensile strength and elongation of 2,100 Mpa (300 ksi) and 3% respectively, were measured. The objective of this proposal is to demonstrate the feasibility of producing superlastic NiTi shape-memory alloy (SMA) foil material by the low pressure spraying (LPPS) technique for the development of robust, corrosion resistant and long life sealing technology. This development may solve a long-standing Naval problem of reliably preventing green water and other fluids or air born contaminants from entering a vessel. In Phase I, a preliminary design and material process technique will be developed and the feasibility of spraying superelastic shape memory alloy foils in various sizes and thickness will be researched. In Phase II, the development of an optimized full scale LPPS system to produce seals is envisioned. Furthermore, the capability to produce continuous lengths of near net shape seals will developed and the superelasticity of the foils produced in Phase I will be characterized.