Effect of tin addition on Nb–Si-based in situ composites. Part II: Oxidation behaviour
| Autor: | Léo Portebois, S. Knittel, Stéphane Mathieu, Michel Vilasi |
|---|---|
| Přispěvatelé: | SNECMA [Paris], SAFRAN Group, Institut Jean Lamour (IJL), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2014 |
| Předmět: |
In situ
Materials science Mechanical Engineering Metals and Alloys Oxide chemistry.chemical_element General Chemistry [CHIM.INOR]Chemical Sciences/Inorganic chemistry Microstructure Oxygen chemistry.chemical_compound Fracture toughness chemistry Mechanics of Materials Materials Chemistry Composite material Tin Internal oxidation Layer (electronics) |
| Zdroj: | Intermetallics Intermetallics, Elsevier, 2014, 47, pp.43-52. ⟨10.1016/j.intermet.2013.12.010⟩ |
| ISSN: | 0966-9795 |
| DOI: | 10.1016/j.intermet.2013.12.010 |
| Popis: | International audience; This paper reports the effects of adding from 2 to 8 at.% tin on the oxidation behaviour of Nb/Nb5Si3 composites at 815 degrees C and at higher temperatures (1100 and 1200 degrees C). The role of tin in the elimination of pesting and in the oxidation process at high temperatures was established. The consumption of elements with a higher affinity for oxygen than Sn induces the accumulation of tin at the oxide/internal oxidation zone boundary. Low melting point phases (NbSn2 and/or pure Sn) form at 815 degrees C, whereas a layer of M5Si3 and Nb5SiSn2 forms at 1100 and 1200 degrees C. Once these products are formed, they generate an oxygen diffusion barrier and allow the elimination of pesting. However, for long oxidation processes at 1100 degrees C, the oxidation rate of Nb/Nb5Si3 composites containing tin should be higher than that for tin-free composites. Moreover, some oxidation results have suggested that the presence of A15-(Nb,Ti)(3)(Sn,Ti) in the microstructure of composites with at.%Sn > 2 can severely impact the low temperature fracture toughness of these composites. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect