Regeneration mechanisms of silver niobate in NiAl composites with respective addition of AgNbO3 and Ag/Nb2O5 at elevated temperatures sliding

• Published in: Tribology international Vol. 153; p. 106623
• Main Authors: Feng, Xiaochun, Jia, Junhong, Gao, Qiang, Lu, Cheng, Yang, Jingjing, Shi, Peiying, Wang, Wenzhen, Yi, Gewen, Wang, Qihua
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.01.2021; Elsevier BV
• Subjects: Aggregation distribution; Composite materials; High temperature; Intermetallic compounds; Monomorphic state; Nickel aluminides; Nickel base alloys; Nickel compounds; Niobium carbide; Niobium oxides; Phases; Regeneration; Silver; Sintering; Tribology; Regeneration; Monomorphic state; Aggregation distribution
• ISSN: 0301-679X; 1879-2464
• DOI: 10.1016/j.triboint.2020.106623

NiAl composites with AgNbO3 (NABO1, NiAl–20 wt%AgNbO3) and Ag/Nb2O5 (NABO2, NiAl–8.68 wt%Ag–10.7 wt% Nb2O5) were fabricated by vacuum-hot-pressing sintering. Their tribological performances were evaluated in the range of 25–800 °C. The regeneration mechanisms of AgNbO3 for the composites with different additions methods during a high-temperature friction process were simultaneously investigated. During sintering, the decomposition of AgNbO3 to Ag/NbC phases was aggregately distributed in NABO1, while Ag/Nb2O5 phases in NABO2 formed Ag and NbC phases that were distributed in a monomorphic state. The regeneration mechanism of AgNbO3 relies on Ag/NbC phases distribution in the composites. Particularly, during the high-temperature friction process, Ag/NbC phases in the aggregate state regenerate AgNbO3 more easily than that in the monomorphic state. •During sintering, the decomposition of AgNbO3 to Ag/NbC phases was aggregately distributed in NABO1 (NiAl–20 wt.%AgNbO3).•Ag/Nb2O5 phases in NABO2 (NiAl–8.68 wt.%Ag–10.7 wt.%Nb2O5) formed Ag and NbC phases distributed in monomorphic state.•The regeneration mechanism of AgNbO3 relies on Ag/NbC phases distribution in the composites.•Ag/NbC in aggregate state regenerate AgNbO3 more easily than that in monomorphic state at high-temperature friction.