Defect formation by order coalescence in vermicular grains during alumina phase transformation

• Vermicular alpha-Al2O3 grains obtained from gamma- to alpha-phase transformation were investigated. X-ray diffraction patterns showed a left-shifting shoulder in all diffraction peaks of transformed alpha-Al2O3. High-resolution transmission electron microscopy results confirmed large amounts of defects inside the vermicular alpha-Al2O3 single-crystal. Combined with grain-growth discontinuity, the authors proposed that the defects inside vermicular grains resulted from assembly of nanosized alpha-crystallites by an ordered coalescence mechanism directly after phase transformation, by which the orientation alignment was thermodynamically favored in the solid-state sintering.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Nanoteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Nano-technology (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering (hsv//eng)

Nyckelord

Defects

Phase transformation

Alumina

Oriented coalescence (OC)

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)