scholarly journals Hot Pressed Silcon Nitride for Gas Turbine Applications

1972 ◽  
Author(s):  
M. L. Torti ◽  
G. Q. Weaver ◽  
D. W. Richerson
Keyword(s):  
Elevated Temperature ◽  
Silicon Nitride ◽  
Thermal Shock ◽  
Gas Turbine ◽  
Thermal Shock Resistance ◽  
Room Temperature ◽  
Promising Candidate ◽  
Shock Resistance ◽  
Room Temperature Strength

The high strengths now attainable with hot pressed silicon nitride combined with its good oxidation and thermal shock resistance make it a most promising candidate for advanced gas turbine hot components. This form of silicon nitride has flexural strengths of 110,000 psi at room temperature and 60,000 psi at 1200 C. A recent experimental version of the system has exhibited room temperature strength of 145,000 psi and elevated temperature (1200 C) strength of 100,000 psi. This may be the highest strength reported on any material at this elevated temperature.

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.

scholarly journals Comparing the influence of different kinds of zirconia on properties and microstructure of Al2O3 ceramics

2016 ◽  
Vol 23 (4) ◽  
pp. 407-412
Author(s):  
Wenfeng Li ◽  
Suping Li ◽  
Xiangchong Zhong
Keyword(s):  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Room Temperature ◽  
Yttria Stabilized Zirconia ◽  
Modulus Of Rupture ◽  
Monoclinic Zirconia ◽  
Stabilized Zirconia ◽  
Microstructure Characteristics ◽  
Shock Resistance ◽  
Room Temperature Strength

AbstractThis paper compared the influence of fused zirconia-corundum (AZ40), monoclinic zirconia (m-ZrO2), and 3 mol% yttria-stabilized zirconia (3Y-ZrO2) on physical properties at room temperature, hot modulus of rupture, and thermal shock resistance of Al2O3 ceramics, and their relationships with microstructure changes were investigated. It was found that m-ZrO2 or 3Y-ZrO2 addition promoted the process of sintering densification and enhanced the room temperature strength and the hot modulus of rupture of Al2O3 ceramics, and the effect of the latter was more distinct, while those of the sample with AZ40 addition decreased. In addition, the three kinds of ZrO2 were beneficial to improving the thermal shock resistance of Al2O3 ceramics. All these changes had close relationships with the changes of corresponding microstructure characteristics (including distribution of particles, degree of contact between crystals, grain boundary solid solution, microcrack density) and phase composition.

Thermal shock resistance of silicon nitride

1977 ◽  
Vol 12 (11) ◽  
pp. 2351-2353 ◽  
Author(s):  
K. Anzai ◽  
H. Hashimoto
Keyword(s):  
Silicon Nitride ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Shock Resistance

Influence of Silicon Nitride on Properties of Corundum Based Castable

2013 ◽  
Vol 634-638 ◽  
pp. 2358-2361
Author(s):  
Jun Cong Wei ◽  
Li Rong Yang
Keyword(s):  
Electron Microscopy ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Cold Strength ◽  
X Ray ◽  
Refractory Castables ◽  
Shock Resistance ◽  
Scanning Electron

The effects of Si3N4 addition on the room temperature physical properties and thermal shock resistance properties of corundum based refractory castables were investigated using brown corundum, white corundum and alumina micropowder as the starting materials and pure calcium aluminate as a binder. The phase composition, microstructure, mechanical properties of corundum based castables were investigated by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that as the increase in Si3N4 addition, the bulk density decreased and apparent porosity increased, the cold strength deduced. However, the residual strength rate increased. That is, the thermal shock resistance was improved. This is because even though the introduction of Si3N4 inhibited the sintering of material and deduced the compactness, microcracks were produced in the materials due to a difference in thermal expansion coefficient. So the thermal shock resistance of corundum based castable was improved.

Thermal shock resistance of silicon nitride ceramics

1988 ◽  
Vol 20 (11) ◽  
pp. 1477-1480 ◽  
Author(s):  
K. A. Kazakyavichyus ◽  
D. V. Narbutene ◽  
E. N. Chasovskoi ◽  
A. F. Batura ◽  
V. G. Verevka
Keyword(s):  
Silicon Nitride ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Nitride Ceramics ◽  
Shock Resistance

Effect of M-ZrO2 on Sintering Behavior and Thermal Shock Resistance of Dense Cr2O3 Material

2011 ◽  
Vol 199-200 ◽  
pp. 1928-1931 ◽  
Author(s):  
Hong Ji Yin ◽  
Tao Zhang ◽  
Ai Jun Wu ◽  
Jin Xiang Wang
Keyword(s):  
Polyvinyl Alcohol ◽  
Oxygen Partial Pressure ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Room Temperature ◽  
Cold Isostatic Pressing ◽  
Sintering Behavior ◽  
Quenching Effect ◽  
Material Sample ◽  
Shock Resistance

The samples were prepared using Cr2O3 micropowder, TiO2 micropowder and m-ZrO2 micropowder as main starting material, polyvinyl alcohol as binder, by a series of processes such as pulping, spraying granulation, machine moulding and cold isostatic pressing, and sintering at 1 500°С for 3 h in nitrogen protected atmosphere furnace (oxygen partial pressure was 10 Pa). Then thermal shock resistance of the samples was tested by wind quenching. Effect of m-ZrO2 (2%-5% in mass) on sintering behavior and thermal shock resistance of Cr2O3 material was investigated. The results show that m-ZrO2 can accelerate the sintering of Cr2O3 material, but excess 2 wt% m-ZrO2 doesn’t work; m-ZrO2 can obviously improve thermal shock resistance of Cr2O3 material, sample containing 3 wt% m-ZrO2 has 34 wind quenching cycles from 1 150°С to room temperature, and sample without m-ZrO2 only has 11 cycles.

Improvement in mechanical properties of sintered zirconia (3% yttria stabilized) by glass infiltration

2007 ◽  
Vol 22 (9) ◽  
pp. 2550-2557 ◽  
Author(s):  
A. Balakrishnan ◽  
B.B. Panigrahi ◽  
Min-Cheol Chu ◽  
T.N. Kim ◽  
Kyung-Jin Yoon ◽  
...  
Keyword(s):  
Surface Stress ◽  
Thermal Shock Resistance ◽  
Room Temperature ◽  
Significant Contribution ◽  
Elastic Stress ◽  
Treated Sample ◽  
Drastic Increase ◽  
Shock Resistance ◽  
Strength Increment ◽  
Room Temperature Strength

The goal of this work was to improve the strength of sintered zirconia (3 mol% yttria stabilized) by surface treatment, using a low expansion glass (Mg3Al2Si6O18) at high temperature. The room-temperature strength was increased by about 42% when the glass was penetrated for 30 min. There was a drastic increase in the Weibull modulus. However, the longer holding time led to grain coarsening and the excess glass deteriorated the strength. The magnitude of the strength increment was on the order of surface stress measured experimentally and thermo-elastic stress predicted theoretically. A significant contribution of phase transformation of zirconia from tetragonal to monoclinic phase on the residual stress was also found. Furthermore, compared to the as-sintered zirconia, the glass-treated sample (penetrated for 30 min) exhibited relatively higher strength at elevated temperature (750 °C) and also showed a significant improvement in the thermal shock resistance behavior.

Effect of Starting Powders on Microstructure and Properties of Silicon Nitride Nanoceramics

2012 ◽  
Vol 217-219 ◽  
pp. 239-244
Author(s):  
Hai Jiang ◽  
Chun Yan Tian
Keyword(s):  
Mechanical Properties ◽  
Silicon Nitride ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Grain Morphology ◽  
Hot Press ◽  
Shock Resistance ◽  
Hot Press Sintering ◽  
Spherical Grains ◽  
Hardness Values

Silicon nitride nanoceramics were fabricated by hot press sintering two kinds of Si3N4nano-sized powders. The effect of starting powders on microstructure, mechanical properties and thermal shock resistance were investigated. The microstructure of sintered materials consists of spherical grains and the addition of α–Si3N4to starting powders does not affect the grain morphology. The flexural strength, fracture toughness and thermal shock resistance increase with the increase in amount of α–Si3N4starting powders, and the maximum mechanical properties are obtained when the amount of α–Si3N4 powders is 40wt.%. The hardness values decrease with the increase of α–Si3N4amount.

Sign in / Sign up

Export Citation Format

Share Document