This title appears in the Scientific Report : 2020 

Performance of wear resistant MCrAlY coatings with oxide dispersion strengthening
Bolelli, Giovanni (Corresponding author)
Vorkötter, Christoph / Lusvarghi, Luca / Morelli, Stefania / Testa, Veronica / Vaßen, Robert
Werkstoffsynthese und Herstellungsverfahren; IEK-1
Wear, 444-445 (2020) S. 203116
Amsterdam [u.a.] Elsevier Science 2020
Journal Article
Methods and Concepts for Material Development
Published on 2019-11-08. Available in OpenAccess from 2021-11-08.
Published on 2019-11-08. Available in OpenAccess from 2021-11-08.
Please use the identifier: in citations.
Please use the identifier: in citations.
Aiming to devise suitable materials for sliding wear protection at high temperature, aluminium oxide-dispersion strengthened (ODS) CoNiCrAlY coatings were manufactured by vacuum plasma spraying (VPS). Feedstock materials were ball-milled powders with 2, 10 and 30 wt% Al2O3 content. The ball-on-disc sliding wear behaviour of the coatings was tested at 750 °C against an Al2O3 counterpart, and compared to a pure CoNiCrAlY coating (obtained from a commercial feedstock not subjected to ball milling) and to an uncoated Ni-base superalloy.Sliding wear rates decrease from the uncoated superalloy (≈3 × 10−5 mm3/(N·m)) to the pure CoNiCrAlY coating (≈2 × 10−5 mm3/(N·m)) and to the ODS ones, with the notable exception of the 10 wt% Al2O3-containing sample.Analyses of worn samples indicate that pure CoNiCrAlY is subject to severe adhesive wear, mitigated by the formation of a thick (>1 μm) “glaze” layer via compaction and (probable) sintering of tribo-oxidized debris particles. Addition of Al2O3 particles to the CoNiCrAlY matrix can either enhance or worsen the “glaze” stability. Specifically, a coating strengthened with 30 wt% Al2O3 provides an especially good mechanical support to the “glaze”. This produces beneficial effects resulting in a particularly low wear rate of ≈3 × 10−6 mm3/(N·m).