Low-temperature anatase-to-rutile phase transformation and unusual grain coarsening in titanium oxide nanopowders by high-pressure torsion straining. (15th March 2019)

• Record Type: Journal Article
• Authors: Edalati, Kaveh; Wang, Qing; Razavi-Khosroshahi, Hadi; Emami, Hoda; Fuji, Masayoshi; Horita, Zenji
• Is Part Of: Scripta materialia. Number 162(2019)
• Page Start: 341
• Page End: 344
• Publication Date: 2019-03-15
• Subjects: Severe plastic deformation (SPD) -- Titanium dioxide (TiO2) -- Phase transition -- Nanostructured ceramics -- Ultrafine-grained (UFG) materials; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2018.11.044
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: Simultaneous effect of pressure, temperature and plastic strain on structural evolution of titania ceramic nanopowder was investigated using the high-pressure torsion (HPT) method. Unlike static annealing, in which the anatase-to-rutile phase transformation occurred at 1173 K, the transformation was observed at low temperatures as 473–573 K by HPT processing. The formation of rutile phase accompanied with dynamic recrystallization and an unusual grain growth, indicating that severe plastic deformation at low homologous temperatures does not necessarily result in grain refinement of metastable nanoceramics. Besides the coarsened grains of rutile phase, a high-pressure TiO2 -II columbite phase was also detected in small nanograins. Graphical abstract: Unlabelled Image