Failure analysis of TiNbCr Multi-Principal element Alloy: Temperature-Dependent oxidation and internal degradation in oxygen atmospheres

Autor(es)

Dainezi, Isabela ; Gleeson, Brian ; Della Rovere, Carlos Alberto

• Tipo de documento: Artigo Científico
• Fonte: ENGINEERING FAILURE ANALYSIS; v. 175, p. 10-pg., 2025-06-15.

Resumo

This study presents a failure analysis of a TiNbCr multi-principal element (MPE) alloy, focusing on its temperature-dependent oxidation behavior and internal degradation mechanisms in oxygen atmospheres. Thermal gravimetric analysis (TGA) conducted at varying temperatures revealed distinct oxidation mechanism: at 700 degrees C, a dense oxide layer formed; at 800 degrees C, a complex mixture of Nb, Ti, and Cr oxides was observed; and at 900 and 1000 degrees C, an innermost Cr2O3-rich layer developed, imparting improved oxidation resistance. Despite these temperature-dependent variations, the scaling kinetics of the alloy remained linear, with extensive internal oxidation observed at all exposure temperatures. In contrast, alloy 188 exhibited parabolic scaling kinetics and lower mass gain per unit area, demonstrating better oxidation resistance. The persistent presence of an internal reaction zone (IRZ) suggests that the oxide scale fails to act as an effective diffusion barrier, promoting internal degradation and increasing the risk of structural failure in high-temperature applications. Moreover, a comparison with previous studies suggests that the presence of nitrogen accelerates oxidation kinetics while reducing IRZ depth, affecting long-term material stability. These findings provide critical insights into oxidation-induced failure mechanisms, aiding in the development and selection of high-temperature alloys for aerospace, energy, and structural applications. (AU)

• Processo FAPESP: 22/03139-9 - Design e produção de ligas multicomponentes refratárias com propriedades otimizadas de oxidação em alta temperatura
• Beneficiário: Carlos Alberto Della Rovere
• Modalidade de apoio: Auxílio à Pesquisa - Projeto Inicial