Alloys and Ceramic Materials for High-Temperature Service

2009 ◽  
pp. 113-113-8 ◽  
Author(s):  
Howard C. Cross
Keyword(s):  
High Temperature ◽  
Ceramic Materials

scholarly journals Superalloy Technology - A Perspective on Critical Innovations for Turbine Engines

2008 ◽  
Vol 380 ◽  
pp. 113-134 ◽  
Author(s):  
Robert Schafrik ◽  
Robert Sprague
Keyword(s):  
High Temperature ◽  
Customer Value ◽  
Oil And Gas ◽  
Driving Forces ◽  
Ceramic Materials ◽  
Nickel Superalloy ◽  
Engineering Practice ◽  
Jet Engines ◽  
Societal Benefit ◽  
Development Paradigm

High temperature structural materials, such as nickel-based superalloys, have contributed immensely to societal benefit. These materials provide the backbone for many applications within key industries that include chemical and metallurgical processing, oil and gas extraction and refining, energy generation, and aerospace propulsion. Within this broad application space, the best known challenges tackled by these materials have arisen from the demand for large, efficient land-based power turbines and light-weight, highly durable aeronautical jet engines. So impressive has the success of these materials been that some have described the last half of the 20th century as the Superalloy Age. Many challenges, technical and otherwise, were overcome to achieve successful applications. This paper highlights some of the key developments in nickel superalloy technology, principally from the perspective of aeronautical applications. In the past, it was not unusual for development programs to stretch out 10 to 20 years as the materials technology was developed, followed by the development of engineering practice, and lengthy production scaleup. And many developments fell by the wayside. Today, there continue to be many demands for improved high temperature materials. New classes of materials, such as intermetallics and ceramic materials, are challenging superalloys for key applications, given the conventional wisdom that superalloys are reaching their natural entitlement level. Therefore, multiple driving forces are converging that motivate improvements in the superalloy development process. This paper concludes with a description of a new development paradigm that emphasizes creativity, development speed, and customer value that can provide superalloys that meet new needs.

Silicon carbide fibers and whiskers for ceramic matrix composites (review)

2021 ◽  
Vol 87 (8) ◽  
pp. 51-63
Author(s):  
A. M. Shestakov
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
High Temperature ◽  
Composite Materials ◽  
Ceramic Matrix Composites ◽  
Ceramic Materials ◽  
Ceramic Composites ◽  
Silicon Compounds ◽  
Reinforcing Fillers ◽  
Operating Temperatures

An increase the operating temperature range of structural elements and aircraft assemblies is one of the main goals in developing advanced and new models of aerospace equipment to improve their technical characteristics. The most heat-loaded aircraft structures, such as a combustion chamber, high-pressure turbine segments, nozzle flaps with a controlled thrust vector, must have a long service life under conditions of high temperatures, an oxidizing environment, fuel combustion products, and variable mechanical and thermal loads. At the same time, modern Ti and Ni-based superalloys have reached the limits of their operating temperatures. The leading world aircraft manufacturers — General Electric (USA), Rolls-Royce High Temperature Composite Inc. (USA), Snecma Propulsion Solide (France) — actively conduct fundamental research in developing ceramic materials with high (1300 – 1600°C) and ultrahigh (2000 – 2500°C) operating temperatures. However, ceramic materials have a number of shortcomings attributed to the high brittleness and low crack resistance of monolithic ceramics. Moreover, manufacturing of complex configuration and large-sized ceramic parts faces serious difficulties. Nowadays, ceramic composite materials with a high-temperature matrix (e.g., based on ZrC-SiC) and reinforcing filler, an inorganic fiber, (e.g., silicon carbide) appeared most promising for operating temperatures above 1200°C and exhibited enhanced energy efficiency. Ceramic fibers based on silicon compounds possess excellent mechanical properties: the tensile strength more than 2 GPa, modulus of elasticity more than 200 GPa, and thermal resistance at a temperature above 800°C, thus making them an essential reinforcing component in metal and ceramic composites. This review is devoted to silicon carbide core fibers obtained by chemical vapor deposition of silicon carbide onto a tungsten or carbon core, which makes it possible to obtain fibers a 100 – 150 μm in diameter to be used in composites with a metal matrix. The coreless SiC-fibers with a diameter of 10 – 20 μm obtained by molding a polymer precursor from a melt and used mainly in ceramic composites are also considered. A comparative analysis of the phase composition, physical and mechanical properties and thermal-oxidative resistance of fibers obtained by different methods is presented. Whiskers (filamentary crystals) are also considered as reinforcing fillers for composite materials along with their properties and methods of production. The prospects of using different fibers and whiskers as reinforcing fillers for composites are discussed.

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