Sintering and Performance of MgO-CaO Materials with Nano-Sized ZrO2 Addition

MgO-CaO materials is one type of the refractories for substitution of MgO-Cr2O3 refractories that has been widely used in metallurgy and cement industries, but the application of MgO-CaO materials has been inhibited for its poor thermal shock resistance that is often improved by addition of ZrO2 but it results in increase of the cost. The present work investigated preparation of MgO-CaO materials by addition of nano-sized ZrO2. The results showed that the densification of the MgO-CaO refractories was promoted and the direct bonding rate of the materials was increased by addition of nano-sized ZrO2. The thermal shock resistance of the MgO-CaO refractories was appreciably improved by modification of the microstructure due to the formed fine CaZrO3 crystallines homogenously locating on the grain boundaries and triple points of the whole microstructure. The critical amount of ZrO2 addition for the purpose to improve thermal shock resistance was effective decreased.

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Preparation and Performance of β-Sialon Bonded ZrO2 Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.415-417.138 ◽

2011 ◽

Vol 415-417 ◽

pp. 138-141

Author(s):

Rui Sheng Wang ◽

Jun Hong Zhao ◽

Ying Na Wei ◽

Fu Hua Peng ◽

Heng Yong Wei

Keyword(s):

Thermal Expansion ◽

Flexural Strength ◽

Thermal Shock ◽

Thermal Shock Resistance ◽

Reaction Sintering ◽

Sintering Process ◽

Carbon Addition ◽

Shock Resistance ◽

And Performance ◽

Sialon Powder

β-Sialon bonded ZrO2 composites were prepared by reaction sintering process using β-Sialon and CaO stabilized ZrO2 powders as raw materials.The effect of β-Sialon powder additions on the properties of the composites was investigated. The results show that the samples with 10 wt% of β-Sialon addition had the lowest apparent porosity (29.80%) and the highest of flexural strength (68.70MPa). The thermal shock resistance in carbon addition of the composites could be improved by addtion of 5wt% β-Sialon. It may be relative with that the sample had the lowest thermal expansion coefficient in vacuum.

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Preparation and Performance of MoB/CoCr Coatings by LPPS on 20G Boiler Steel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.201-203.2623 ◽

2011 ◽

Vol 201-203 ◽

pp. 2623-2629

Author(s):

Xiao Chen ◽

Ren Yuan Zhang ◽

Feng Li

Keyword(s):

Bond Strength ◽

Thermal Shock ◽

Thermal Shock Resistance ◽

Thermal Power ◽

Thermal Spraying ◽

Boiler Steel ◽

Phase Component ◽

High Durability ◽

Shock Resistance ◽

And Performance

MoB/CoCr, a novel material for thermal spraying, with high durability in molten alloys is used to resist erosion by molten Al-Si alloy in solar thermal power generation. The microstructure and phase component of coatings were characterized, and the coatings were also studied on bond strength and thermal shock resistance. The durability of the MoB/CoCr coatings prepared by low pressure plasma spraying (LPPS) has been investigated using a molten-metal immersion tester. The results showed that phase component of powder and coating had little change. The coatings have dense structure and excellent combination with substrate. The main constituents of coatings remain invariant and the coatings have excellent properties of bond strength and thermal shock resistance. The immersion tests revealed that the MoB/CoCr coating has much higher durability without dissolution in the molten Al-12.07wt.%Si alloy.

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