Partial Stabilized Zirconia (PSZ) was prepared from adding 3 wt % of MgO or adding 8 wt% of Y 2 O 3 to 90 wt % ZrO 2 Powder and mixed by wet method, then dried and firing mixture to 1500C to obtain PSZ ceramic powder. Glass-Ceramic (Li 2 SiO 3 ) and (LiAlO 2 ) prepared by dissolve lithium carbonate and lithium hydroxide with Nano-Silica (SiO 2 ) and Nano-Alumina (Al 2 O 3 ) respectively. Those glass-ceramic mixed with PSZ in different percentage (2.5,5,7.5,10) and sprayed on furnaces bricks for petroleum refineries. An increase in the chemical resistance of the acid on the surface of the Refractory bricks was observed when coating with the glass-ceramic mixture, as well as increasing the hardness and thermal shock resistance. Lithium silicate coated specimens are more spared and homogeneous on the surface compared to lithium laminate coated.

The objective of this work is to study the effect of adding varying ratios of Nano Alumina to the glazing powder on glazing layer of restorative dental ceramic. The effect of addition is examined by applying Vickers hardness and surface roughness tests on the glazing layer. The specimens have been cut in a cubic form. The specimens were placed in the furnace for sintering up to temperature of 1450 oC. One specimen is glazed with glazing materials and the remaining three specimens are glazed with glazing materials but supported with varying ratios of Nano Alumina (10, 15 and 25 wt%) and all these specimens sintered at 850 oC. It was found that Vickers hardness is increased with increasing the ratios of Nano Alumina but the surface roughness decreased with increasing the ratios of Nano Alumina. Weibull modulus increased with Alumina additive increases for glass coating layer.

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The process of ceramic or refractory surfaces coating is one of the methods used to protect the ceramic body from chemical effects resulting from operating conditions, especially in the applications that include acid gases emissions such as furnaces of petroleum refining units. A mixture of low-melting glass frit was used, reinforced with nano powders of zirconia and Partial Stabilized Zirconia with yttria (3Y-PSZ) with different additives 5wt% and 10 wt%, as well as the addition of nano-alumina for the same percentage of addition. The medium alumina refractory brick which used in lining petroleum refining units was used as a basis for coating. The coating process was implemented after mixing and preparation of a homogeneous suspension in the presence of water, then drying and sintering until glazing at a temperature of 850 oC. X-ray diffraction technique was used to show the structural characterization of the glazing, which indicated that a glass frit layer was transformed into a mixture of ceramic-glass (crystalline glass), where the crystalline structures of the nano powders were clearly visible. Surface roughness showed low values for frit added with 5wt% of (3Y-PSZ) as well as the frit to which was added 10 %wt of (3Y-PSZ with 5wt% alumina). Moreover, all samples showed clear chemical resistance against acids, including concentrated H2SO4. Thermal shock resistance varied for vitrification mixtures, but it was good for vitrified samples, adding 10%wt of (3Y-PSZ) with 5wt% alumina as well as adding silicate to the mixture, and these mixtures are considered to be the best in medium alumina refractory surfaces coating.

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