A novel tool to assess the influence of alloy composition on the oxidation behavior and concurrent oxygen-induced phase transformations for binary Ti–xMo alloys at 650°C

• Published in: Corrosion science Vol. 89; pp. 295 - 306
• Main Authors: Samimi, P., Liu, Y., Ghamarian, I., Collins, P.C.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.12.2014; Elsevier
• Subjects: Applied sciences; Corrosion; Corrosion environments; Exact sciences and technology; Metals. Metallurgy; Oxidation; SEM; TEM; Titanium; XRD; Titanium; Oxidation; SEM; XRD; TEM; Scanning electron microscopy; Phase transformation; Transmission electron microscopy; Corrosion; Composition effect; Binary alloy
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2014.09.010

•A novel combinatorial approach was used to assess the oxidation of Ti–Mo system.•Oxygen-assisted precipitation of β particles in α was observed for <7.5wt% Mo.•Discontinuous precipitation is a result of oxygen ingress for >7.5wt% Mo.•Scale adhesion is degraded with increase in Mo wt% via formation of a TiO layer.•Parabolic oxidation rate is being obeyed in the studied composition-time domain. To understand the influence of composition on the oxidation of the Ti–Mo system, a combinatorial approach was adopted whereby a compositionally graded specimen, Ti–xMo (0⩽x⩽12wt%), was prepared and oxidized at 650°C. The results show that the scale thickness is independent of the composition and a parabolic law is obeyed in the composition-time domain. An increase in the Mo content degrades the adhesion of the scale by forming a TiO transition layer. Some of the observations including the homogeneous nucleation of β for compositions <∼7.5wt% Mo and discontinuous precipitation for compositions >∼7.5wt% Mo in the subsurface region have not been previously reported.