Properties of sputter deposited Ni-base superalloys for microelectromechanical systems

• Exceptional room temperature strength (2 GPa) and ductility after aging
• Sputtered superalloy had a similar composition as the target.
• Film was essentially quenched from the vapor forming a solid solution.
• Heat treatment resulted in unique precipitation pathways.
• Small grain size contributed to mechanical properties and precipitation.

Nickel-base superalloy 718 films have been sputter deposited to thicknesses of 20 μm. These as-deposited films were single-phase nanocrystalline solid solutions, which possessed tensile strengths of 1 GPa but negligible ductility. Standard 718 aging heat treatments resulted in modest grain growth, atypical precipitation behavior, significant ductility, and impressive strengths at both ambient (2 GPa at 25 °C) and elevated (750 MPa at 700 °C) temperatures. The density of grain boundaries was shown to have a dramatic effect on the precipitation pathways of this alloy.