Densification and grain boundary nitrides in spark plasma sintered SAF 2205 -TiN composite

Autor: Samuel Ranti Oke, Oluwasegun Eso Falodun, Peter Apata Olubambi, J.E. Westraadt, Oladeji Oluremi Ige
Rok vydání: 2019
Předmět:
Zdroj: International Journal of Refractory Metals and Hard Materials. 81:78-84
ISSN: 0263-4368
Popis: Densification and nature of α-ferrite γ-austenite interface associated with the spark plasma sintering (SPS) of SAF 2205 reinforced with TiN nanoparticles was investigated. The sintering data obtained during SPS was used to evaluate the densification mechanism. EBSD and TKD technique were used to characterize the SAF 2205 composite. The grain and grain boundary properties were evaluated using nanoindentation technique. Three densification stages relating to particles rearrangement, bulk deformation and rapid densification of the SAF 2205 composite was observed during SPS. The EBSD revealed a reverse ferrite to austenite phase transformation and a refined microstructure after SPS. TKD analysis of the grain boundary showed nanosized sintered-in nitride coexisting with ferrite and austenite upon sintering at α/γ interface but also at α/α and γ/γ interfaces. TKD-EDS compositional mapping revealed Ti-rich grain boundary. Nanoindentation experiments reveal that the TiN dominated grain boundaries exhibit lower penetration depths, an indication of higher hardness and modulus.
Databáze: OpenAIRE