Properties of sputter deposited Ni-base superalloys for microelectromechanical systems

Nanotwinned metal MEMS films with unprecedented strength and stability

“…Films for the current study were sputtered using a dc power of 2500 W and an argon working pressure of 1.0 mtorr for 150 min. The Ar pressure and dc power were carefully chosen to achieve films with low residual stress and ensure a dense microstructure without surface microcracks ( 41 ). Two targets, Ni–15 at % Mo and Ni–15 at % W, were co-sputtered on a brass substrate to create films with compositional spread, and a relatively molybdenum-rich (compared to tungsten) region was selected for this study.…”

Multicomponent Precipitation and Strengthening in Intermetallic-Strengthened Alloys

“…The selective laser melting of a (FeCoNi) 86 Ti 7 Al 7 alloy produces a heterogeneous precipitate microstructure consisting of L1 2 precipitates inside cellular structures and B2 precipitates along the cellular boundaries, which is quite different from the traditionally heat-treated microstructure with a uniform distribution of L1 2 nanoparticles (Huang et al, 2022). The sputtered Inconel 718 films generally show the precipitation of multicomponent δ-Ni 3 Nb precipitates, whereas in bulk 718 alloys metastable γ′′-Ni 3 Nb precipitates form first and transform to the stable δ-Ni 3 Nb phase after prolonged aging times (Burns et al, 2014). These observations suggest that different processing methods can result in different microstructures in terms of precipitate types, sizes, volume fractions, morphologies, and distributions.…”

Magnetron Sputtering as a Microstructural Screening Tool for Laser Additive Manufacturing: Study on Ni Superalloys

“…[88] Notably, γ 00 and γ 0 strengthening precipitates appear to be suppressed in the heat-treated sputtered films, which has been observed in other magnetron-sputtered Ni superalloys. [70,71,89] However, the lack of γ 00 could be due to the formation of the δ-phase via phase transformation, [90] which may be accelerated due to the residual stress conditions and high density of interfaces present in the films. [89] Furthermore, since γ 0 sites serve as nucleation zones for γ 00 , [91] they may also be lost during this phase transformation.…”

“…[70,71,89] However, the lack of γ 00 could be due to the formation of the δ-phase via phase transformation, [90] which may be accelerated due to the residual stress conditions and high density of interfaces present in the films. [89] Furthermore, since γ 0 sites serve as nucleation zones for γ 00 , [91] they may also be lost during this phase transformation. Altogether, the results from this study suggest that magnetron sputtering plus heat treatment can facilitate similar microstructures to those achieved in bulk AM Inconel alloys independent of the target type used, likely due to similarities in as-prepared residual stress conditions and compositions.…”