Advanced Ceramics for Environmental Protection

1994 ◽  
Vol 344 ◽  
Author(s):  
Jeffrey A. Chambers
Keyword(s):  
Silicon Carbide ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Ceramic Materials ◽  
Environmental Applications ◽  
Fiber Reinforced ◽  
Gas Filtration ◽  
Advanced Ceramic ◽  
Hot Gas ◽  
Shock Resistance

AbstractAdvanced ceramic materials offer significant thermodynamic efficiency advantages over metals and alloys because of their higher use temperatures. Using ceramic components results in higher temperature industrial processes which convert fuels to energy more efficiently, reducing environmental emissions. Ceramics have always offered high temperature strength and superior corrosion and erosion resistance. However, brittleness, poor thermal shock resistance and catastrophic failure have slowed industrial adoptions of ceramics in environmental applications.This paper will focus on environmental applications of three new advanced ceramic materials that are overcoming these barriers to industrial utilization through improved toughness, reliability, and thermal shock performance. PRD-66, a layered oxide ceramic with outstanding thermal shock resistance and high use temperature with utility in catalyst support, insulation, and hot gas filtration applications, is discussed. Tough silicon carbide fiber reinforced silicon carbide (SiC/SiC) and carbon fiber reinforced silicon carbide (C/SiC) ceramic composites made by chemical vapor infiltration, and silicon carbide particulate reinforced alumina (SiCp/A12O3) composites made through Lanxide Corporation's DIMOX™ directed metal oxidation process are described. Applications of these materials to pollution reduction and energy efficiency in medical and municipal waste incineration, heat management, aluminum remelting, pyrolysis, coal combustion and gasification, catalytic pollution control, and hot gas filtration, will be discussed.

Reaction Bonded Silicon Carbide and Silicon Nitride for Gas Turbine Applications

1972 ◽  
Author(s):  
R. A. Alliegro ◽  
S. H. Coes
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Silicon Nitride ◽  
Thermal Shock ◽  
Gas Turbine ◽  
Thermal Shock Resistance ◽  
Casting Process ◽  
Ceramic Materials ◽  
Machining Process ◽  
Shock Resistance

Two unique ceramic materials offer the gas turbine designer the opportunity to substitute uncooled high temperature components for the presently cooled metal and alloy ones. Recrystallized silicon carbide made by a casting process and reaction bonded silicon nitride shaped by a simple machining process before firing, offer not only high temperature materials capable of living in the gas turbine environment, but also an intricacy of shape consistent with combustor, shroud and associated high temperature component needs. Silicon carbide’s 3200 F capability and its thermal shock resistance makes it a sound choice; silicon nitride’s low expansion coefficient, thermal shock resistance, and 2900 F capability make it a material of real merit. The properties of these materials are discussed in detail along with potential areas of application and design capabilities.

Thermal Shock Resistance of Liquid Phase Sintered SiC

2016 ◽  
Vol 881 ◽  
pp. 103-108
Author(s):  
Roberta Monteiro de Mello ◽  
Ana Helena de Almeida Bressiani
Keyword(s):  
Silicon Carbide ◽  
Liquid Phase ◽  
Thermal Shock ◽  
Water Samples ◽  
Thermal Cycle ◽  
Thermal Shock Resistance ◽  
Sintering Temperature ◽  
Shock Resistance

The aim of this study was to evaluate the effect of Y2O3:Al2O3 additives and sintering temperature on thermal shock resistance of silicon carbide sintered via liquid phase. Silicon carbide samples containing 10 mol% Y2O3:Al2O3 (1:3 and 1:4) were prepared, compacted and sintered at 1750, 1850 and 1950 °C in a graphite resistive furnace. Thermal shock resistance was evaluated after each thermal cycle performed at 600, 750 and 900 °C followed by abrupt cooling in water. Samples with two Y2O3:Al2O3 proportions did not show major differences when sintered at the same temperature, though, rising the sintering temperature improves Y2O3:Al2O3 modified-SiC thermal shock resistance.

Influence of Additives on Performance of Silicon Carbide Refractory

2012 ◽  
Vol 538-541 ◽  
pp. 2277-2280
Author(s):  
You Fu Guo ◽  
Ming Yue Zheng ◽  
Jing Long Bu ◽  
Yue Jun Chen ◽  
Li Xue Yu ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Thermal Expansion ◽  
Bulk Density ◽  
Thermal Shock ◽  
Silica Fume ◽  
Thermal Shock Resistance ◽  
Bending Strength ◽  
Carbide Refractory ◽  
Shock Resistance ◽  
Silicon Carbide Refractory

Silicon carbide with diffierent granularity was used as raw material, quartz, silica fume, aluminum powder or alumina was used as additive with dosages of 1% (in mass, similarly hereinafter), 3% and 5%. Silicon carbide refractory material was prepared in oxidizing atmosphere at 1400 °C for 3 h. Performence of samples were researched by measurements of apparent porosity, bulk density, bending strength at room temperature, thermal shock resistance and thermal expansion rate, and analyzed by SEM. The results showed that samples added silica fume have low thermal expansion rate and apparent porosity, high bending strength and bulk density, good thermal shock resistance, compact texture as well. It can be deduced that 5% silica fume plays the excellent role to improve integrated performance of silicon carbide refractory material.

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