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Hollow Casting
Permanent mold casting is a metal casting process that employs reusable molds ("permanent molds"), usually made from metal. The most common process uses gravity to fill the mold, however gas pressure or a vacuum are also used. A variation on the typical gravity casting process, called slush casting, produces hollow castings. Common casting metals are aluminium, magnesium, and copper alloys. Other materials include tin, zinc, and lead alloys and iron and steel are also cast in graphite molds.. Typical products are components such as gears, splines, wheels, gear housings, pipe fittings, fuel injection housings, and automotive engine pistons. Process There are four main types of permanent mold casting: gravity, slush, low-pressure, and vacuum. Gravity process The gravity process begins by preheating the mold to 150–200 °C (300–400 °F). to ease the flow and reduce thermal damage to the casting. The mold cavity is then coated with a refractory material or a mold ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fuel Injector
Fuel injection is the introduction of fuel in an internal combustion engine, most commonly automotive engines, by the means of an injector. This article focuses on fuel injection in reciprocating piston and Wankel rotary engines. All compression-ignition engines (e.g. diesel engines), and many spark-ignition engines (i.e. petrol engines, such as Otto or Wankel), use fuel injection of one kind or another. Mass-produced diesel engines for passenger cars (such as the Mercedes-Benz OM 138) became available in the late 1930s and early 1940s, being the first fuel-injected engines for passenger car use. In passenger car petrol engines, fuel injection was introduced in the early 1950s and gradually gained prevalence until it had largely replaced carburettors by the early 1990s. The primary difference between carburetion and fuel injection is that fuel injection atomizes the fuel through a small nozzle under high pressure, while a carburettor relies on suction created by intake a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hollowcast
Permanent mold casting is a metal casting process that employs reusable molds ("permanent molds"), usually made from metal. The most common process uses gravity to fill the mold, however gas pressure or a vacuum are also used. A variation on the typical gravity casting process, called slush casting, produces hollow castings. Common casting metals are aluminium, magnesium, and copper alloys. Other materials include tin, zinc, and lead alloys and iron and steel are also cast in graphite molds.. Typical products are components such as gears, splines, wheels, gear housings, pipe fittings, fuel injection housings, and automotive engine pistons. Process There are four main types of permanent mold casting: gravity, slush, low-pressure, and vacuum. Gravity process The gravity process begins by preheating the mold to 150–200 °C (300–400 °F). to ease the flow and reduce thermal damage to the casting. The mold cavity is then coated with a refractory material or a mold ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hollow Cast
Permanent mold casting is a metal casting process that employs reusable molds ("permanent molds"), usually made from metal. The most common process uses gravity to fill the mold, however gas pressure or a vacuum are also used. A variation on the typical gravity casting process, called slush casting, produces hollow castings. Common casting metals are aluminium, magnesium, and copper alloys. Other materials include tin, zinc, and lead alloys and iron and steel are also cast in graphite molds.. Typical products are components such as gears, splines, wheels, gear housings, pipe fittings, fuel injection housings, and automotive engine pistons. Process There are four main types of permanent mold casting: gravity, slush, low-pressure, and vacuum. Gravity process The gravity process begins by preheating the mold to 150–200 °C (300–400 °F). to ease the flow and reduce thermal damage to the casting. The mold cavity is then coated with a refractory material or a mold ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hollowcasting
Permanent mold casting is a metal casting process that employs reusable molds ("permanent molds"), usually made from metal. The most common process uses gravity to fill the mold, however gas pressure or a vacuum are also used. A variation on the typical gravity casting process, called slush casting, produces hollow castings. Common casting metals are aluminium, magnesium, and copper alloys. Other materials include tin, zinc, and lead alloys and iron and steel are also cast in graphite molds.. Typical products are components such as gears, splines, wheels, gear housings, pipe fittings, fuel injection housings, and automotive engine pistons. Process There are four main types of permanent mold casting: gravity, slush, low-pressure, and vacuum. Gravity process The gravity process begins by preheating the mold to 150–200 °C (300–400 °F). to ease the flow and reduce thermal damage to the casting. The mold cavity is then coated with a refractory material or a mold ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hollow Casting
Permanent mold casting is a metal casting process that employs reusable molds ("permanent molds"), usually made from metal. The most common process uses gravity to fill the mold, however gas pressure or a vacuum are also used. A variation on the typical gravity casting process, called slush casting, produces hollow castings. Common casting metals are aluminium, magnesium, and copper alloys. Other materials include tin, zinc, and lead alloys and iron and steel are also cast in graphite molds.. Typical products are components such as gears, splines, wheels, gear housings, pipe fittings, fuel injection housings, and automotive engine pistons. Process There are four main types of permanent mold casting: gravity, slush, low-pressure, and vacuum. Gravity process The gravity process begins by preheating the mold to 150–200 °C (300–400 °F). to ease the flow and reduce thermal damage to the casting. The mold cavity is then coated with a refractory material or a mold ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Riser (casting)
A riser, also known as a feeder, is a reservoir built into a metal casting mold to prevent cavities due to shrinkage. Most metals are less dense as a liquid than as a solid so castings shrink upon cooling, which can leave a void at the last point to solidify. Risers prevent this by providing molten metal to the casting as it solidifies, so that the cavity forms in the riser and not the casting.. Risers are not effective on materials that have a large freezing range, because directional solidification is not possible. They are also not needed for casting processes that utilized pressure to fill the mold cavity. Theory Risers are only effective if three conditions are met: the riser cools after the casting, the riser has enough material to compensate for the casting shrinkage, and the casting directionally solidifies towards the riser. For the riser to cool after the casting the riser must cool more slowly than the casting. Chvorinov's rule briefly states that the slowest cooling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molding Sand
Molding sand, also known as foundry sand, is a sand that when moistened and compressed or oiled or heated tends to pack well and hold its shape. It is used in the process of sand casting for preparing the mold cavity. Green sand Green sand is an aggregate of sand, bentonite clay, pulverized coal and water. Its principal use is in making molds for metal casting. The largest portion of the aggregate is a sand, either most-commonly silica or sometimes olivine. There are many recipes for the proportion of clay, but they all strike different balances between moldability, surface finish, and ability of the hot molten metal to degas. The coal, typically referred to in as sea-coal, which is present at a ratio of less than 5%, partially combusts in the surface of the molten metal leading to offgassing of organic vapors. Sand casting is one of the earliest forms of casting practiced due to the simplicity of materials involved. It still remains one of the cheapest ways to cast metals beca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Fatigue
Thermo-mechanical fatigue (short TMF) is the overlay of a cyclical mechanical loading, that leads to fatigue of a material, with a cyclical thermal loading. Thermo-mechanical fatigue is an important point that needs to be considered, when constructing turbine engines or gas turbines. Failure mechanisms There are three mechanisms acting in thermo-mechanical fatigue * Creep is the flow of material at high temperatures *Fatigue is crack growth and propagation due to repeated loading *Oxidation is a change in the chemical composition of the material due to environmental factors. The oxidized material is more brittle and prone to crack creation. Each factor has more or less of an effect depending on the parameters of loading. In phase (IP) thermo-mechanical loading (when the temperature and load increase at the same time) is dominated by creep. The combination of high temperature and high stress is the ideal condition for creep. The heated material flows more easily in tension, but cools ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hot Tear
Hot or the acronym HOT may refer to: Food and drink *Pungency, in food, a spicy or hot quality *Hot, a wine tasting descriptor Places *Hot district, a district of Chiang Mai province, Thailand **Hot subdistrict, a sub-district of Hot District, Thailand ** Tha Kham, Chiang Mai, also known as Hot, a town in Hot District, Chiang Mai province, Thailand *Hot, Albania, a village in the Malësi e Madhe municipality, Shkodër County, Albania Music * H.O.T. pronounced "H. O. T.", (High-Five of Teenagers), a South Korean boy band *Hawaii Opera Theatre, an opera company in Honolulu, Hawaii *Hot (American vocal group), best known for 1977 hit "Angel in Your Arms" 1976–1980 *Hot 97, branding for hip-hop radio station WQHT in New York City Albums * ''Hot'' (Freda Payne album), 1979 * ''Hot'' (Half Japanese album), 1995 * ''Hot'' (Inna album) or the title song (see below), 2009 * ''Hot'' (James Brown album) or the title song (see below), 1976 * ''Hot'' (Mel B album), 2000 * ''Hot'' (Paul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molten Metal
Melting, or fusion, is a physical process that results in the phase transition of a substance from a solid to a liquid. This occurs when the internal energy of the solid increases, typically by the application of heat or pressure, which increases the substance's temperature to the melting point. At the melting point, the ordering of ions or molecules in the solid breaks down to a less ordered state, and the solid "melts" to become a liquid. Substances in the molten state generally have reduced viscosity as the temperature increases. An exception to this principle is the element sulfur, whose viscosity increases in the range of 160 °C to 180 °C due to polymerization. Some organic compounds melt through mesophases, states of partial order between solid and liquid. First order phase transition From a thermodynamics point of view, at the melting point the change in Gibbs free energy ''∆G'' of the substances is zero, but there are non-zero changes in the enthal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Core (casting)
A core is a device used in casting and moulding processes to produce internal cavities and reentrant angles (an interior angle that is greater than 180°). The core is normally a disposable item that is destroyed to get it out of the piece.. They are most commonly used in sand casting, but are also used in die casting and injection moulding. For example, cores define multiple passages inside cast engine blocks. One model of GM V-8 engine requires 5 dry-sand cores for every casting. Materials required to make cores *Core sand *Bentonite clay *Pulverized coal *Resin oil Advantages and disadvantages Cores are useful for features that cannot tolerate draft or to provide detail that cannot otherwise be integrated into a core-less casting or mold. The main disadvantage is the additional cost to incorporate cores. Requirements There are seven requirements for cores: #Green strength: In the green condition, there must be adequate strength for handling #In the hardened state, it must b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
