scholarly journals Intrinsic Thermal Shock Behavior of Common Rutile Oxides

Physics ◽  
2019 ◽  
Vol 1 (2) ◽  
pp. 290-300 ◽  
Author(s):  
Denis Music ◽  
Bastian Stelzer
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Elastic Modulus ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Density Functional ◽  
Coefficient Of Thermal Expansion ◽  
Thermomechanical Properties ◽  
Linear Coefficient ◽  
Shock Resistance

Rutile TiO2, VO2, CrO2, MnO2, NbO2, RuO2, RhO2, TaO2, OsO2, IrO2, SnO2, PbO2, SiO2, and GeO2 (space group P42/mnm) were explored for thermal shock resistance applications using density functional theory in conjunction with acoustic phonon models. Four relevant thermomechanical properties were calculated, namely thermal conductivity, Poisson’s ratio, the linear coefficient of thermal expansion, and elastic modulus. The thermal conductivity exhibited a parabolic relationship with the linear coefficient of thermal expansion and the extremes were delineated by SiO2 (the smallest linear coefficient of thermal expansion and the largest thermal conductivity) and PbO2 (vice versa). It is suggested that stronger bonding in SiO2 than PbO2 is responsible for such behavior. This also gave rise to the largest elastic modulus of SiO2 in this group of rutile oxides. Finally, the intrinsic thermal shock resistance was the largest for SiO2, exceeding some of the competitive phases such as Al2O3 and nanolaminated Ti3SiC2.

A new high thermal shock resistant onelayer glass–ceramic coating for industrial and engineering applications

2017 ◽  
Vol 2 (82) ◽  
pp. 70-76
Author(s):  
J.H. Mohmmed
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Ceramic Coating ◽  
Lithium Oxide ◽  
Coating System ◽  
Glass Ceramic Coating ◽  
Resultant Coating ◽  
Shock Resistance

Purpose: A new high thermal stability single layer glass–ceramic coating system designing for applied on various grade of steel alloy has been developed in this work. Design/methodology/approach: The thermal shock resistance, thermal conductivity and thermal expansion of the coating system were evaluated by using suitable standard tests. Some crystalline agents (Lithium oxide Li2O, Titanium oxide TiO2, Zircon ZrSiO4 and Feldspar CaO∙Al2O3∙2SiO2) were add at constant ratio 6% to coating system to evaluate their effects on the resultant coatings. Findings: The results indicate the suitability of these coatings for protection of metal substrate. Also the results show that the properties of resultant coating were hardly affected by composition and concentration of crystalline agent. Research limitations/implications: Coating with lithium oxide has the lowest thermal expansion, which means the highest thermal shock resistance. While, values of thermal conductivity were too close for all types of coating. Originality/value: Generally, the resultant coating properties have been enhanced in all cases; this is associated with the introduce the crystalline agent which lead to the formation of a complex network of crystalline phases.

Utilization of Fly Ash in the Synthesis of Refractory Forsterite-Spinel Ceramics

2021 ◽  
Vol 321 ◽  
pp. 131-140
Author(s):  
Martin Nguyen ◽  
Radomír Sokolař
Keyword(s):  
Thermal Expansion ◽  
Fly Ash ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Power Plants ◽  
Linear Thermal Expansion ◽  
Aluminium Oxide ◽  
Raw Material ◽  
Modulus Of Rupture ◽  
Shock Resistance

Forsterite refractory ceramics is utilized in the metallurgical and cement industries as a lining of metallurgical furnaces and rotary kilns for its high refractoriness up to 1850°C and refractoriness under load above 1600°C. Another significant property of forsterite is its coefficient of linear thermal expansion utilized in the electrotechnical industry for ceramic-metal joints. Addition of aluminium oxide into the raw material mixture results in creation of magnesium-alumina spinel (MgO·Al2O3) which improves sintering, thermal shock resistance and mechanical properties in comparison with pure forsterite ceramics. Inexpensive source of aluminium oxide is fly ash. Utilization of fly ash, secondary energetic product of coal-burning power plants, is important for the environment and sustainable development. This paper evaluated properties of fly ash-based forsterite-spinel ceramics in comparison with alumina-based forsterite-spinel ceramics. Forsterite-spinel ceramics was synthesized from olivine, calcined magnesite and fly ash/alumina powders. XRD analysis was used to determine mineralogical composition, thermal analyses were used to determine the behaviour during firing and scanning electron microscopy to determine the morphology of crystal phases. Refractoriness of pyrometric cones, refractoriness under load, thermal shock resistance, coefficient of linear thermal expansion, water absorption, porosity and modulus of rupture were also determined on fired test samples.

Influence of Zircon Addition on Thermal Shock Resistance of ZTA for Plasma Reactors

2007 ◽  
Vol 544-545 ◽  
pp. 379-382
Author(s):  
Kyung Hun Jang ◽  
Bum Rae Cho
Keyword(s):  
Thermal Expansion ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Sintering Temperature ◽  
Plasma Reactors ◽  
Alumina Ceramics ◽  
Low Thermal Expansion ◽  
Resultant Data ◽  
Shock Resistance ◽  
Zirconia Toughened Alumina

The effect of CaO, MgO and SiO2 as a flux on the sinterability of zirconia toughened alumina(ZTA) used for plasma reactors was investigated and the effect of zircon addition on thermal shock resistance of ZTA with 15wt.% of ZrO2 was also investigated. The resultant data revealed that ZTA shows the best sinterability at the composition of 2wt.% of CaO, 4wt.% of MgO and 2wt.% of SiO2 and at the sintering temperature of 1350°C. Thermal shock resistance of ZTA containing zircon was improved significantly. It is shown that ZTA containing 10wt.% of zircon shows better thermal shock resistance than others. This fact can be explained due to the low thermal expansion coefficient of zircon. It was concluded that zircon is an effective material to improve thermal shock resistance of alumina ceramics.

Effect of MgO/CuO on the Microstructure and Thermal Properties of Cordierite–Alumina Ceramics

2012 ◽  
Vol 509 ◽  
pp. 240-244
Author(s):  
Li Ying Tang ◽  
Xi Cheng ◽  
Ping Lu ◽  
Fang Yue
Keyword(s):  
Thermal Conductivity ◽  
Bulk Density ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Raw Materials ◽  
Laser Flash ◽  
Alumina Powder ◽  
Alumina Ceramics ◽  
Conductivity Increase ◽  
Shock Resistance

Abstract: Cordierite–alumina ceramics were prepared with the raw materials of cordierite and α-alumina powder, and TiO2，CuO and MgO were added as composite additives. The effect of MgO/ CuO ratios on the microstructure, thermal conductivity and thermal shock resistance of cordierite–alumina ceramics were researched by X-ray diffraction, scanning electron microscopy and laser flash analyzer; the bulk density and the porosity of cordierite – alumina ceramics were measured. The results show that with increasing of MgO/CuO ratios, the bulk density and thermal conductivity increase firstly and then decrease, and have a minimum with 0.4wt% MgO and 0.667 MgO/CuO; and the porosity of ceramics decreases firstly and then increases and has a maximum with 0.4wt% MgO and 0.667 MgO/CuO;There are little changes in the size of the grain of the ceramics, and a small amount of magnesium aluminate spinel precipitate; the thermal shock resistance performance of the ceramics is developed with the increasing of MgO/CuO ratios.

Preparation and Performance of β-Sialon Bonded ZrO2 Composites

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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