Grain growth in nanograined aluminum oxide by high-pressure torsion: Phase transformation and plastic strain effects

作者：Fujita Ikuro; Edalati Kaveh^*; Sauvage Xavier; Horita Zenji

来源：Scripta Materialia, 2018, 152: 11-14.

DOI：10.1016/j.scriptamat.2018.04.003

• Transition aluminas
• Phase transition
• Nanostructured ceramics
• Ultrafine grains (UFG)
• Gamma phase

Application of severe plastic deformation (SPD) to different materials usually leads to significant grain refinement and accelerated phase transformations. This study reports the occurrence of grain growth in nanocrystalline A1(2)O(3) by SPD processing via high-pressure torsion (HPT) due to a phase transformation from gamma with the cubic structure to a with the rhombohedral structure. This transformation was significantly enhanced by pressure and plastic strain and occurred at similar to 650 K below the gamma -> alpha transition temperature. The gamma phase after HPT processing could be detected only in nanograins or in the nano-sized laths with the (1 (3) over bar1)gamma//(01 (4) over bar)alpha and [001]gamma/[100]alpha coherent orientation relationship.

• 出版日期2018-7-15