Observation of Cu-rich grain boundary nanoparticles and complexions in Cu/Ti-doped alumina. (December 2018)

• Record Type: Journal Article
• Authors: Marvel, C.J.; Kracum, M.R.; Yu, Z.; Harmer, M.P.; Chan, H.M.
• Is Part Of: Scripta materialia. Number 157(2018)
• Page Start: 34
• Page End: 38
• Publication Date: 2018-12
• Subjects: Alumina -- Reduction -- Interfacial segregation -- Scanning/transmission electron microscopy (STEM) -- Metal complexionized ceramics; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2018.07.032
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: Alumina powders were processed with 7.8 wt% CuO and post-sintering reduction heat-treatments were applied with the aim of producing metallic grain boundary complexions. The influence of titanium co-doping was also studied. Grain boundaries were characterized by aberration-corrected scanning transmission electron microscopy. Copper grain boundary enrichment was achieved, but only in the titanium doped samples; the segregated copper exhibited a Cu 2+ valency state, the segregated titanium exhibited Ti 3+ or Ti 4+ valency states, and metallic Cu nanoparticles were also observed. The crystallographic orientation of the grain boundary plane had a marked influence on concentration and oxidation state of the segregating species. Graphical abstract: Unlabelled Image