Recent developments in hybrid low pressure thermal spray technologies such as Plasma Spray-Thin Film (PS-TF), PS-PVD, PS-CVD are being increasingly used to develop functional inorganic coatings and films for emerging high end energy applications. The requirements of such coatings and films are more highly specified than those of conventional plasma spray coatings. Successful film deposition therefore requires not only the development and application of novel operating parameters, but also goes hand-in-hand with tailored feedstock materials development. Targeted development by Sulzer Metco has allowed applications to evolve into fields where conventionally competitive manufacturing technologies would be applied; potentially enabling entirely new fields of plasma spray manufacturing to emerge. Such applications include corrosion protection and electrolytic films in SOFC, gas tight mixed electron and ion conducting membranes for gas separation and thin, transparent functional layers in photo-voltaic applications. This paper provides a brief overview of the status of developments of several high end emerging energy applications which are being developed using such hybrid low pressure plasma spray technologies.

Reliable and economically efficient processes are necessary for the production of high quality coatings for solid oxide fuel cells (SOFC) applications in an industrial scale. In that perspective, Sulzer Metco developed several coating solutions through different processes adapted for each specific applications, in particular on metal supported cells (MSC). Diffusion barrier layers (DBL) using perovskite material, such as Lanthanum Strontium Manganite (LSM), is produced “state-of-the-art” as coating service by Sulzer Metco on metallic interconnects (IC) using the Triplex technology. The newly developed TriplexPro-200 having a long lifetime performance and specific features, like cascaded arc and 3-cathode torch, is the best candidate for producing high quality and reliable coatings in a mass production of SOFC functional layers. LPPS-Thin Film, on the other hand is the technology of choice to deposit very dense, thin and homogeneous layers on various substrates. Yttria stabilized Zirconia (YSZ) layers of 20-40 µm thickness have been deposited on thin metallic substrates (0.7 mm, 140 cm 2 ) without producing any strong deformation of the substrate. Considering the dimension of the metallic substrate the coated cells present very good gas leak tightness performances between 2 and 8 Pa·m/s which is homogeneous on the substrate area. Moreover, LPPS-TF can also be used to produce very dense and thin LSM coatings on interconnects. In this case, LPPS-TF not only produces denser and thinner coatings but also becomes again competitive when considering the manufacturing of DBL for metallic ICs on a high production scale. This paper presents the current developments of these technologies in the domain of SOFC applications.

With the new development of the LPPS Thin-Film technology (LPPS-TF), which is a special modification of conventional LPPS using reduced chamber pressures below 10 mbar, a new window has been opened to deposit uniform and dense thin layers onto large areas in short coating times. This spray process will allow the access to new market areas and will be able to bridge the gap between conventional thin film (< 1 - 10 µm) deposition using PVD/CVD processes and thick (> 50 - 200 µm) thermally sprayed layers. This paper presents the status of the LPPS-Thin Film technology as a hybrid coating process between thermal spray and vapor deposition and gives an overview of potential applications for functional thin coatings and large area coverage.