Influence of Si doping and O2-flow on arc deposited (Al,Cr)2O3 coatings

Ludvig Landälv; Emmanuelle Göthelid; Jens Jensen; Grzegorz Greczynski; Jun Lu; Mats Ahlgren; Lars Hultman; Björn Alling; Per Eklund

arXiv · 1910.09380

Influence of Si doping and O2-flow on arc deposited (Al,Cr)2O3 coatings

Ludvig Landälv·Emmanuelle Göthelid·Jens Jensen·Grzegorz Greczynski·Jun Lu·Mats Ahlgren·Lars Hultman·Björn Alling·Per Eklund

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Abstract

(Al,Cr)2O3 coatings with Al/(Al+Cr) = 0.5 or Al = 70 at.%, doped with 0, 5 or 10 at.% Si, were deposited on hard metal and Si(100) substrates to elucidate the influence of Si on the resulting coatings. The chemical analysis of the coatings showed between 3.3 and 7.4 at.% metal fraction Si incorporated into all studied coatings depending on cathode Si-composition. The incorporated Si content does not change significantly with different oxygen flow covering a wide range of deposition conditions from low to high O2 flow during growth. The addition of Si promotes the metastable B1-like cubic structure over the thermodynamically stable corundum structure. The hardness determined by nanoindentation of the as-deposited coatings is slightly reduced upon Si-incorporation as well as upon increased Al-content. Si is found enriched in droplets but can also be found at a lower content, evenly spread, without visible segregation on the ~5 nm scale, in the actual oxide coating. The positive effect of improved cathode erosion upon Si-incorporation has to be balanced against the promotion of the metastable B1-like structure, having lower room temperature hardness and inferior thermal stability compared to the corundum structure.

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Ludvig Landälv, Emmanuelle Göthelid, Jens Jensen, Grzegorz Greczynski, Jun Lu, Mats Ahlgren, Lars Hultman, Björn Alling, Per Eklund. 2019-10-21. Influence of Si doping and O2-flow on arc deposited (Al,Cr)2O3 coatings. https://arxiv.org/abs/1910.09380

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