A Continuous β-NiAl Layer Forming at the Interface of a MCrAlY and CMSX-4
2016 (English)In: Journal of thermal spray technology (Print), ISSN 1059-9630, E-ISSN 1544-1016, Vol. 25, no 1, 244-251 p.Article in journal (Refereed) Published
A large test sample of single-crystal superalloy (CMSX-4) deposited with a MCrAlY coating of γ and β phases was subjected to a thermal-cycling fatigue (TCF) test at 1100 °C for about 300 cycles. Near the coating-substrate interface where an inner β-depletion zone often develops in the coating for other superalloy-MCrAlY systems, a continuous β-layer was formed instead for this particular system after the TCF test. The formation of the β-layer was related to the accumulation of Al at the interface. Simulations using an oxidation-diffusion model were carried out on this and a number of other superalloy-MCrAlY systems. It was derived that the formation of the β-layer at the interface was likely due to the high Al activity of CMSX-4 which resisted the inward diffusion of Al from the coating. The simulation results also indicated a positive effect provided by the formation of the β-layer on the coating’s oxidation resistance.
Place, publisher, year, edition, pages
Springer, 2016. Vol. 25, no 1, 244-251 p.
Al activity, CMSX-4, diffusion, MCrAlY
IdentifiersURN: urn:nbn:se:liu:diva-123740DOI: 10.1007/s11666-015-0293-4ISI: 000374268000025OAI: oai:DiVA.org:liu-123740DiVA: diva2:892802