91Zr NMR characterisation of phases in transformation toughened zirconia

✍ Scribed by T.J. Bastow; M.E. Smith

• Book ID: 104357779
• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 509 KB
• Volume: 1
• Category: Article
• ISSN: 0926-2040
• DOI: 10.1016/s0926-2040(10)80001-3

✦ Synopsis

A detailed 91Zr NMR investigation is presented of the five component (cubic, monoclinic, tetragonal, orthorhombic and (i) phase mixture in the transformation toughened engineering ceramic, magnesia-partially-stabilised zirconia (MgPSZ). The phases are distinguished on the basis of the quadrupole interaction displayed in the powder pattern of the 91Zr (1/2, -1/2) transition.

This paper reports: (i) the first characterisation of the magnesia-fully-stabilised cubic phase at the eutectic composition (13.5 mol% MgO); (ii) the observation of a poorly ordered tetragonal phase on fast cooling Zr02 (9.3 mol% MgO) from the cubic phase field at 1720°C, and the subsequent growth and ordering of the tetragonal phase precipitates due to further annealing; (iii) the observation of the (partial) transformation of the cubic phase to the ordered (i-phase (Mg 2ZrS012) on annealing MgPSZ at lIOO°C for 8 h; and (iv) the observation of the transformation of the tetragonal phase into the orthorhombic phase after cooling in liquid nitrogen, and the reverse transformation after heating to 600°C.