scholarly journals Development of a Low Thermal Expansion Magnesium-Aluminum-Silicate Ceramic for Gas Turbine Heat Exchanger Applications

1975 ◽  
Author(s):  
Sergej-Tomislav Buljan ◽  
R. N. Kleiner
Keyword(s):  
Thermal Expansion ◽  
Heat Exchanger ◽  
Gas Turbine ◽  
Ceramic Materials ◽  
Aluminum Silicate ◽  
Factors Influencing ◽  
Low Thermal Expansion ◽  
Magnesium Aluminum Silicate ◽  
Silicate Ceramic

A review of the factors influencing the thermal expansion of ceramic materials is presented. Studies have shown that thermal expansions lower than the theoretical value predicted for cordierite can be obtained. The properties of a low thermal expansion magnesium-aluminum-silicate ceramic developed for gas turbine heat exchanger applications are described.

Reliability and Durability of Ceramic Regenerators in a Gas Turbine

1978 ◽  
Vol 100 (1) ◽  
pp. 73-81 ◽  
Author(s):  
C. J. Rahnke ◽  
J. K. Vallance
Keyword(s):  
Thermal Stress ◽  
Gas Turbine ◽  
Mechanical Design ◽  
Ceramic Materials ◽  
Aluminum Silicate ◽  
Turbine Engine ◽  
Design Concepts ◽  
Chemical Attack ◽  
Magnesium Aluminum Silicate ◽  
Regenerator System

The two major causes of failure of ceramic regenerators in a gas turbine engine are excessive thermal stress and chemical attack of the basic ceramic material. Data are presented which show that regenerator life can be correlated on the basis of rim thermal-stress safety factor. Durability gains can be achieved through improved mechanical design of the regenerator system, as well as through improved ceramic materials. The test results from almost 50,000 hr of gas turbine operation on several different candidate materials and design concepts are also presented. Two materials, aluminum silicate and magnesium aluminum silicate, show promise of achieving the durability goals required for automotive and industrial turbine applications.

Fracture Strength and Thermal Shock Resistance of Thick And Thin-Wall Magnesium-Aluminum-Silicate Ceramic Heat Regenerators

1978 ◽  
Vol 100 (1) ◽  
pp. 136-139
Author(s):  
J. J. Cleveland ◽  
C. W. Fritsch ◽  
R. N. Kleiner
Keyword(s):  
Heat Exchanger ◽  
Thermal Shock ◽  
Fracture Strength ◽  
Thermal Shock Resistance ◽  
Thick Wall ◽  
Aluminum Silicate ◽  
Thin Wall ◽  
Magnesium Aluminum Silicate ◽  
Shock Resistance ◽  
Silicate Ceramic

Thin-wall regenerator cores offer the potential for higher effectiveness than comparable thick-wall cores. The fracture strength of magnesium-aluminum-silicate (MAS) ceramic heat-exchanger cores with wall thickness of 0.083 mm (0.003 in.) and 0.160 mm (0.006 in.) are compared. Thermal shock resistance calculations for these cores are also presented.

Development of Cast Glass-Ceramic Turbine Housings

1982 ◽  
Author(s):  
J. G. Lanning ◽  
D. A. Noll
Keyword(s):  
Thermal Expansion ◽  
Gas Turbine ◽  
Glass Ceramic ◽  
Process Development ◽  
Ceramic Materials ◽  
Ford Motor Company ◽  
Turbine Engine ◽  
Low Thermal Expansion ◽  
Turbine Housing ◽  
Engine Components

Corning became actively involved with vehicular gas turbine programs in 1952 during the development of a ceramic rotary regenerator core for the Chrysler automotive gas turbine. Material and process development research in this program led to efforts to apply very low thermal expansion, modest strength, sintered glass-ceramic materials to some of the static gas turbine engine components. One early program involved the first stage turbine plenum for the Ford Model 707 industrial gas turbine. Several process/material iterations ultimately led to the development of a glass-ceramic turbine housing for the Ford Motor Company Model 820 ceramic gas turbine. The housing required a sophisticated slip cast process and a special lithium aluminosilicate (LAS) glass-ceramic composition (Corning Code 9458) with a total thermal expansion between room temperature and 1200C of about 700 ppm. This paper reviews this project and indicates some possible directions for future developments. The design concept and application of the glass-ceramic housing to the Ford Model 820 ceramic gas turbine is discussed in an associated ASME paper by Mr. A. F. McLean of Ford Motor Company.

scholarly journals Ceramic Components for Automotive and Heavy Duty Turbine Engines: CATE and AGT 100

1982 ◽  
Author(s):  
H. E. Helms ◽  
J. A. Byrd
Keyword(s):  
Gas Turbine ◽  
Operating Time ◽  
Ceramic Materials ◽  
Turbine Engines ◽  
Aluminum Silicate ◽  
Lithium Aluminum ◽  
Gas Turbine Engines ◽  
Design Component ◽  
Controllable Factors ◽  
Ceramic Components

Detroit Diesel Allison is actively applying advanced ceramic materials to components in gas turbine engines. Silicon carbide, silicon nitride, aluminum silicate, lithium aluminum silicate, and mullite are materials being used in various components in both the DDA GT 404-4 and AGT 100 engines. Approximately 9400 hr of ceramic component operating time in the GT 404 engine has been accumulated, and design, component processing, proof testing, and engine testing experience have begun to show the applicability of ceramic materials in production engines. Material variability, processing procedures, strength characterization, and nondestructive evaluations are emerging as critical but controllable factors. Ceramic components offer the potential of significant fuel consumption improvements in gas turbine engines for vehicles and other applications.

A New Low-Thermal-Expansion, High-Strength Alloy for Gas Turbines

1989 ◽  
Author(s):  
S. K. Srivastava ◽  
George Y. Lai
Keyword(s):  
Thermal Expansion ◽  
Gas Turbine ◽  
Gas Turbines ◽  
High Strength ◽  
Environmental Resistance ◽  
Minor Elements ◽  
Low Thermal Expansion ◽  
Strength Alloy ◽  
Long Range Ordering ◽  
Cr System

HAYNES® alloy No. 242, based on Ni-Mo-Cr system, was developed primarily for turbine seal applications. The key characteristics of the alloy are derived from critical control of Ni, Mo, Cr, and several minor elements. The high strength — about twice that of alloy B — is achieved from a long-range ordering reaction. The paper reviews comparative evaluation of 242™ alloy versus several currently used gas-turbine alloys such as alloys B, S, N and INCOLOY® alloy 909. Environmental resistance is particularly emphasized. It is shown that 242 alloy possesses an excellent combination of low-thermal-expansion, high strength, and environmental resistance for gas turbine service up to 1400°F (760°C).

Comparison of Porous Ceramic Materials with Low Thermal Expansion Coefficient Prepared with SiC and Black-Al2O3

2008 ◽  
Vol 569 ◽  
pp. 321-324
Author(s):  
Isaías Juárez-Ramírez ◽  
Koji Matsumaru ◽  
Kozo Ishizaki ◽  
Leticia M. Torres-Martínez
Keyword(s):  
Thermal Expansion ◽  
Room Temperature ◽  
Raw Materials ◽  
Porous Ceramic ◽  
Ceramic Materials ◽  
X Ray Diffraction ◽  
Low Thermal Expansion ◽  
New Phase ◽  
Porous Ceramic Materials ◽  
Made In

Porous ceramic materials with low thermal expansion (LTE) at room temperature were prepared by heating a mixture of SiC or black-Al2O3, vitrified bonding material (VBM) and LiAlSiO4 at temperatures from 850°C to 1100°C. The mixture was prepared in adequate proportions to obtain a material with LTE according to previous works made in our laboratory. It was observed that a change in temperature provoked the formation of a new phase, LiAlSi3O8, which appears above 900°C. The presence of this new phase did not affect the thermal expansion value, keeping LTE at room temperature. All compounds showed around 40% of porosity, and Young’s modulus values of 30 GPa using black-Al2O3 or SiC. X-ray diffraction analysis (XRD) revealed that above 900°C the phase LiAlSi3O8 starts to appear as a consequence of the melting of VBM, which is reacting with the raw materials. SEM micrographs showed the presence of SiC or black-Al2O3 grains joined by VBM, which is acting as a bridge between them.

scholarly journals Ablation behavior and mechanism of boron nitride - magnesium aluminum silicate ceramic composites in an oxyacetylene combustion flame

2018 ◽  
Vol 44 (2) ◽  
pp. 1518-1525 ◽  
Author(s):  
Delong Cai ◽  
Zhihua Yang ◽  
Jingkun Yuan ◽  
Xiaoming Duan ◽  
Shengjin Wang ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Ceramic Composites ◽  
Aluminum Silicate ◽  
Combustion Flame ◽  
Magnesium Aluminum Silicate ◽  
Silicate Ceramic

Aluminous Keatite—An Improved Rotary Ceramic Regenerator Core Material

1978 ◽  
Vol 100 (1) ◽  
pp. 36-39 ◽  
Author(s):  
D. G. Grossman ◽  
J. G. Lanning
Keyword(s):  
Thermal Expansion ◽  
Gas Turbines ◽  
Combustion Process ◽  
Diesel Oil ◽  
Hydrogen Ion ◽  
Core Material ◽  
Aluminum Silicate ◽  
Lithium Aluminum ◽  
Low Thermal Expansion ◽  
New Material

Rotary lithium aluminum silicate (LAS) ceramic regenerator cores for gas turbines have had limited durability in applications using sulphur bearing hydrocarbon fuels such as diesel oil. The presence of sulphuric acid from the combustion process caused a lithium/hydrogen ion exchange and resulted in core failure. This paper describes a unique low thermal expansion aluminous keatite material (Corning Code 9460) which was developed to overcome the foregoing problem. Cores made from this new material have now operated over 6000 hr in Ford 707 gas turbines.

INCONEL Alloy 783: An Oxidation Resistant, Low Expansion Superalloy for Gas Turbine Applications

1996 ◽  
Author(s):  
K. A. Heck ◽  
J. S. Smith ◽  
R. Smith
Keyword(s):  
Thermal Expansion ◽  
Gas Turbine ◽  
Coefficient Of Thermal Expansion ◽  
Alloy System ◽  
Alloy Development ◽  
Turbine Engine ◽  
Inconel Alloy ◽  
Al Content ◽  
Low Thermal Expansion ◽  
Oxidation Resistant

INCONEL® alloy 783 is an oxidation resistant low coefficient of thermal expansion (low CTE) superalloy developed for gas turbine applications. Turbine efficiency can be increased through the use of low CTE shrouds and case components that maintain tight blade tip clearances at different turbine operating temperatures. To achieve low CTE, alloys based on Ni-Fe-Co compositions require Cr content be maintained at low levels. Added Cr lowers the Curie temperature and thereby increases thermal expansion rate over a wider temperature range. The necessary lack of Cr minimizes resistance to both general oxidation and stress accelerated grain boundary oxygen enhanced cracking (SAGBO). Increased amounts of Al in alloys strengthened by γ’ alone also promotes SAGBO. Alloy 783 is the culmination in the development of an alloy system with very high aluminum content that, in addition to forming γ′, causes β aluminide phase precipitation in the austenitic matrix. It was discovered that this type of structure can be processed to resist both SAGBO and general oxidation, while providing low thermal expansion and useful mechanical properties up to 700°C. The high Al content also reduces density to 5% below that of superalloys such as INCONEL alloy 718. Key aspects of the alloy development are presented, including the assessment of SAGBO resistance by evaluating elevated temperature crack growth in air. The alloy, now commercially available, has been successfully fabricated and welded into gas turbine engine components.

Sign in / Sign up

Export Citation Format

Share Document