Grain zirconia

Duclos, R., Direct observation of grain rearrangement during superplastic creep of a fine-grained zirconia , J. Eur. Ceram. Soc., 2004, 24, 3103-10. 

C.S. Chen, Fine grained zirconia-metal dual phase composites, PhD Thesis, University... 

Zirconia, Zr02- Although zirconia has been used in the refractories industry for close to a century, only recently has advanced, stabilized, fine-grained zirconia come into widespread use. The combination of hardness, good thermal insulation, chemical inertness, high density, low coefficient of fiiction, expansion coefficient close to that of steel, and high fracture toughness has made various forms of zirconia attractive for many applications. 

Chen, C.S., Fine Grained Zirconia-Metal Dual Phase Composites, Ph.D. thesis. University of Twente, The Netherlands, 1994. 

C. lonascu. High temperature mechanical spectroscopy of fine-grained zirconia and alumina containing nano-sized reinforcements. Ph.D. Thesis. 2008. 

Fig. 2. RepHca electron micrograph of the fracture surface of enstatite—P-spodumene—zirconia glass-ceramic, showing twinning in the enstatite grains...

Zirconium oxide is fused with alurnina in electric-arc furnaces to make alumina—zirconia abrasive grains for use in grinding wheels, coated-abrasive disks, and belts (104) (see Abrasives). The addition of zirconia improves the shock resistance of brittle alurnina and toughens the abrasive. Most of the baddeleyite imported is used for this appHcation, as is zirconia produced by burning zirconium carbide nitride. 

Application of AES to zirconia ceramics has been reported by Moser et al. [2.146]. Elemental maps of Al and Si demonstrate the grain boundary segregation of small impurities of silica and alumina in these ceramics. 

A recent development is the introduction of ZGS (Zirconia Grain Stabilised) platinum. This is produced by the addition of a small amount of zirconia (zirconium(IV) oxide) to molten platinum, which leads to modification of the microstructure of the solid material with increased hot strength and greater resistance to chemical attack. Whereas the recommended operating temperature for pure platinum is 1400 °C, the ZGS material can be used up to 1650 °C. 

---