Chemical vapor deposition (CVD) is a vacuum deposition method used to produce high-quality, and high-performance, solid materials. The process is often used in the semiconductor industry to produce thin films.
In materials science, a metal matrix composite (MMC) is a composite material with fibers or particles dispersed in a metallic matrix, such as copper, aluminum, or steel. The secondary phase is typically a ceramic or another metal. They are typically classified according to the type of reinforcement: short discontinuous fibers (whiskers), continuous fibers, or particulates. There is some overlap between MMCs and cermets, with the latter typically consisting of less than 20% metal by volume. When at least three materials are present, it is called a hybrid composite. MMCs can have much higher strength-to-weight ratios, stiffness, and ductility than traditional materials, so they are often used in demanding applications. MMCs typically have lower thermal and electrical conductivity and poor resistance to radiation, limiting their use in the very harshest environments.
Silicon carbide (SiC), also known as carborundum, is a hard chemical compound containing silicon and carbon. A semiconductor, it occurs in nature as the extremely rare mineral moissanite, but has been mass-produced as a powder and crystal since 1893 for use as an abrasive. Grains of silicon carbide can be bonded together by sintering to form very hard ceramics that are widely used in applications requiring high endurance, such as car brakes, car clutches and ceramic plates in bulletproof vests. Large single crystals of silicon carbide can be grown by the Lely method and they can be cut into gems known as synthetic moissanite.
Fibre-reinforced plastic is a composite material made of a polymer matrix reinforced with fibres. The fibres are usually glass, carbon, aramid, or basalt. Rarely, other fibres such as paper, wood, boron, or asbestos have been used. The polymer is usually an epoxy, vinyl ester, or polyester thermosetting plastic, though phenol formaldehyde resins are still in use.
Carbon fibre reinforced carbon (CFRC), carbon–carbon (C/C), or reinforced carbon–carbon (RCC) is a composite material consisting of carbon fiber reinforcement in a matrix of graphite. It was developed for the reentry vehicles of intercontinental ballistic missiles, and is most widely known as the material for the nose cone and wing leading edges of the Space Shuttle orbiter. Carbon-carbon brake discs and brake pads have been the standard component of the brake systems of Formula One racing cars since the late 1970s; the first year carbon brakes were seen on a Formula One car was 1976.
Metalorganic vapour-phase epitaxy (MOVPE), also known as organometallic vapour-phase epitaxy (OMVPE) or metalorganic chemical vapour deposition (MOCVD), is a chemical vapour deposition method used to produce single- or polycrystalline thin films. It is a process for growing crystalline layers to create complex semiconductor multilayer structures. In contrast to molecular-beam epitaxy (MBE), the growth of crystals is by chemical reaction and not physical deposition. This takes place not in vacuum, but from the gas phase at moderate pressures. As such, this technique is preferred for the formation of devices incorporating thermodynamically metastable alloys, and it has become a major process in the manufacture of optoelectronics, such as Light-emitting diodes. It was first demonstrated in 1967 at North American Aviation Autonetics Division in Anaheim CA by Harold M. Manasevit.
Zirconium carbide (ZrC) is an extremely hard refractory ceramic material, commercially used in tool bits for cutting tools. It is usually processed by sintering.
Ceramic engineering is the science and technology of creating objects from inorganic, non-metallic materials. This is done either by the action of heat, or at lower temperatures using precipitation reactions from high-purity chemical solutions. The term includes the purification of raw materials, the study and production of the chemical compounds concerned, their formation into components and the study of their structure, composition and properties.
Prof. Roger R. Naslain is French chemical and physical scientist. He has been a professor at the University of Bordeaux 1 since 1969.
Zirconium diboride (ZrB2) is a highly covalent refractory ceramic material with a hexagonal crystal structure. ZrB2 is an ultra-high temperature ceramic (UHTC) with a melting point of 3246 °C. This along with its relatively low density of ~6.09 g/cm3 (measured density may be higher due to hafnium impurities) and good high temperature strength makes it a candidate for high temperature aerospace applications such as hypersonic flight or rocket propulsion systems. It is an unusual ceramic, having relatively high thermal and electrical conductivities, properties it shares with isostructural titanium diboride and hafnium diboride.
In materials science ceramic matrix composites (CMCs) are a subgroup of composite materials and a subgroup of ceramics. They consist of ceramic fibers embedded in a ceramic matrix. The fibers and the matrix both can consist of any ceramic material, including carbon and carbon fibers.
AlSiC, pronounced "alsick", is a metal matrix composite consisting of aluminium matrix with silicon carbide particles. It has high thermal conductivity, and its thermal expansion can be adjusted to match other materials, e.g. silicon and gallium arsenide chips and various ceramics. It is chiefly used in microelectronics as substrate for power semiconductor devices and high density multi-chip modules, where it aids with removal of waste heat.
Tailored fiber placement (TFP) is a textile manufacturing technique based on the principle of sewing for a continuous placement of fibrous material for composite components. The fibrous material is fixed with an upper and lower stitching thread on a base material. Compared to other textile manufacturing processes fiber material can be placed near net-shape in curvilinear patterns upon a base material in order to create stress adapted composite parts.
In nuclear fusion power research, the plasma-facing material (PFM) is any material used to construct the plasma-facing components (PFC), those components exposed to the plasma within which nuclear fusion occurs, and particularly the material used for the lining the first wall or divertor region of the reactor vessel.
Ultra-high-temperature ceramics (UHTCs) are a type of refractory ceramics that can withstand extremely high temperatures without degrading, often above 2,000 °C. They also often have high thermal conductivities and are highly resistant to thermal shock, meaning they can withstand sudden and extreme changes in temperature without cracking or breaking. Chemically, they are usually borides, carbides, nitrides, and oxides of early transition metals.
SiC–SiC matrix composite is a particular type of ceramic matrix composite (CMC) which have been accumulating interest mainly as high temperature materials for use in applications such as gas turbines, as an alternative to metallic alloys. CMCs are generally a system of materials that are made up of ceramic fibers or particles that lie in a ceramic matrix phase. In this case, a SiC/SiC composite is made by having a SiC matrix phase and a fiber phase incorporated together by different processing methods. Outstanding properties of SiC/SiC composites include high thermal, mechanical, and chemical stability while also providing high strength to weight ratio.
In materials science, a polymer matrix composite (PMC) is a composite material composed of a variety of short or continuous fibers bound together by a matrix of organic polymers. PMCs are designed to transfer loads between fibers of a matrix. Some of the advantages with PMCs include their light weight, high resistance to abrasion and corrosion, and high stiffness and strength along the direction of their reinforcements.
Silicon carbide fibers are fibers ranging from 5 to 150 micrometres in diameter and composed primarily of silicon carbide molecules. Depending on manufacturing process, they may have some excess silicon or carbon, or have a small amount of oxygen. Relative to organic fibers and some ceramic fibers, silicon carbide fibers have high stiffness, high tensile strength, low weight, high chemical resistance, high temperature tolerance and low thermal expansion. (refs) These properties have made silicon carbide fiber the choice for hot section components in the next generation of gas turbines, e.g. the LEAP engine from GE.
Ultra-high temperature ceramic matrix composites (UHTCMC) are a class of refractory ceramic matrix composites (CMCs) with melting points significantly higher than that of typical CMCs. Among other applications, they are the subject of extensive research in the aerospace engineering field for their ability to withstand extreme heat for extended periods of time, a crucial property in applications such as thermal protection systems (TPS) and rocket nozzles. Carbon fiber-reinforced carbon (C/C) maintains its structural integrity up to 2000 °C; however, C/C is mainly used as an ablative material, designed to purposefully erode under extreme temperatures in order to dissipate energy. Carbon fiber reinforced silicon carbide matrix composites (C/SiC) and Silicon carbide fiber reinforced silicon carbide matrix composites (SiC/SiC) are considered reusable materials because silicon carbide is a hard material with a low erosion and it forms a silica glass layer during oxidation which prevents further oxidation of inner material. However, above a certain temperature starts the active oxidation of silicon carbide matrix to gaseous silicon monoxide, consequently loss of protection from further oxidation, which leads the material to an uncontrolled and fast erosion. For this reason C/SiC and SiC/SiC are used in the range of temperature between 1200° - 1400 °C.
The Fraunhofer Center for High Temperature Materials and Design is a research center of the Fraunhofer Institute for Silicate Research in Würzburg, a research institute of the Fraunhofer Society. It predominantly conducts research in high temperature technologies energy-efficient heating processes and thus contributes to sustainable technological progress. It is headquartered in Bayreuth and has additional locations in Würzburg and Münchberg.
