Thermochemical calculations of the oxidation behavior of Nb2AlC MAX phase in ZrO2–matrix composites. Issue 13 (September 2018)

• Record Type: Journal Article
• Authors: Stumpf, Martin; Biggemann, Jonas; Fey, Tobias; Kakimoto, Ken-ichi; Greil, Peter
• Is Part Of: Ceramics international. Volume 44:Issue 13(2018)
• Page Start: 15747
• Page End: 15753
• Publication Date: 2018-09
• Subjects: Nb2AlC oxidation -- Thermo-chemical calculations -- Oxide scale formation; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2018.05.249
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: The oxidation behavior of Y-TZP/Nb2 AlC composite was explored by thermo-chemical phase equilibrium calculations and experimental oxidation studies at 1200 °C. Growth of a compact surface reaction layer requires migration of oxygen from the surface to the reaction front and a gradient of oxygen content is likely to develop. The results of phase equilibria calculations show that at low oxygen concentration preferential oxidation of Al favors thermal degradation of Nb2 AlC which yields Al2 O3 and Nb-carbides. With increasing oxygen content various Nb-oxides are formed and finally a mixture of NbAlO4 and Nb2 O5 is present after full oxidation of a Nb2 AlC particle. Experimental measurements confirmed the formation of a compact oxidation reaction layer at 1200 °C composed mainly of NbAlO4 and a co-doped (Nb, Y)-TZP matrix.