|
Foundry Sand Testing
Foundry sand testing is a process used to determine if the foundry sand has the correct properties for a certain casting process. The sand is used to make moulds and cores via a pattern. In a sand casting foundry there are broadly two reasons for rejection of the casting — metal and sand — each of which has a large number of internal variables. The defects arising from the sand can be prevented by using sand testing equipment to measure the various properties of the sand. Process The testing process is divided into four stages: sampling of the bulk material, sample sand preparation, specimen preparation and testing. It is done at three different points of the process: upon first arrival from the supplier, en transport for processing (usually on a conveyor), and after processing. In each situation it is important to take a representative sample by mixing the sand or by taking multiple samples in different locations. Also, the sample must be stored in an airtight c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foundry 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] |
Casting (metalworking)
In metalworking and jewelry making, casting is a process in which a liquid metal is delivered into a mold (usually by a crucible) that contains a negative impression (i.e., a three-dimensional negative image) of the intended shape. The metal is poured into the mold through a hollow channel called a sprue. The metal and mold are then cooled, and the metal part (the ''casting'') is extracted. Casting is most often used for making complex shapes that would be difficult or uneconomical to make by other methods. Casting processes have been known for thousands of years, and have been widely used for sculpture (especially in bronze), jewelry in precious metals, and weapons and tools. Highly engineered castings are found in 90 percent of durable goods, including cars, trucks, aerospace, trains, mining and construction equipment, oil wells, appliances, pipes, hydrants, wind turbines, nuclear plants, medical devices, defense products, toys, and more. Traditional techniques include lost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mold (manufacturing)
Molding (American English) or moulding (British and Commonwealth English; see spelling differences) is the process of manufacturing by shaping liquid or pliable raw material using a rigid frame called a mold or matrix. This itself may have been made using a pattern or model of the final object. A mold or mould is a hollowed-out block that is filled with a liquid or pliable material such as plastic, glass, metal, or ceramic raw material. The liquid hardens or sets inside the mold, adopting its shape. A mold is a counterpart to a cast. The very common bi-valve molding process uses two molds, one for each half of the object. Articulated molds have multiple pieces that come together to form the complete mold, and then disassemble to release the finished casting; they are expensive, but necessary when the casting shape has complex overhangs. Piece-molding uses a number of different molds, each creating a section of a complicated object. This is generally only used for larger a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Core (manufacturing)
A core is a device used in casting and molding (process), moulding processes to produce internal cavities and wikt:reentrant, 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 (engineering), 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 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pattern (casting)
In casting, a pattern is a replica of the object to be cast, used to prepare the cavity into which molten material will be poured during the casting process. Patterns used in sand casting may be made of wood, metal, plastics or other materials. Patterns are made to exacting standards of construction, so that they can last for a reasonable length of time, according to the quality grade of the pattern being built, and so that they will repeatably provide a dimensionally acceptable casting. Patternmaking The making of patterns, called patternmaking (sometimes styled pattern-making or pattern making), is a skilled trade that is related to the trades of tool and die making and moldmaking, but also often incorporates elements of fine woodworking. Patternmakers (sometimes styled pattern-makers or pattern makers) learn their skills through apprenticeships and trade schools over many years of experience. Although an engineer may help to design the pattern, it is usually a patternmaker w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Foundry Society
The American Foundry Society (AFS) is a professional, technical and trade association for foundries and the broader metal casting industry. The society promotes the interests of foundries to policymakers, provides training for foundry workers, and supports research and technological advancements in foundry science and manufacturing. AFS represents ferrous and nonferrous foundries based in North America, as well as industry suppliers and end-users of metal castings from around the world. The society has individual and corporate members across 48 countries, organized into regional chapters and student chapters in the United States, Canada and Mexico. AFS presents Metalcasting Congress, a yearly industry conference, as well as CastExpo, a trade show and exposition that occurs every three years. AFS is based in Schaumburg, Illinois, and also maintains an office in Washington, D.C. Doug Kurkul is CEO of the organization. History The American Foundry Society traces its roots to 1896 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bentonite
Bentonite () is an absorbent swelling clay consisting mostly of montmorillonite (a type of smectite) which can either be Na-montmorillonite or Ca-montmorillonite. Na-montmorillonite has a considerably greater swelling capacity than Ca-montmorillonite. Bentonite usually forms from the weathering of volcanic ash in seawater, or by hydrothermal circulation through the porosity of volcanic ash beds, which converts (devitrification) the volcanic glass ( obsidian, rhyolite, dacite) present in the ash into clay minerals. In the mineral alteration process, a large fraction (up to 40-50 wt.%) of amorphous silica is dissolved and leached away, leaving the bentonite deposit in place. Bentonite beds are white or pale blue or green (traces of reduced ) in fresh exposures, turning to a cream color and then yellow, red, or brown (traces of oxidized ) as the exposure is weathered further. As a swelling clay, bentonite has the ability to absorb large quantities of water, which increa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pitch Powder
Pitch may refer to: Acoustic frequency * Pitch (music), the perceived frequency of sound including "definite pitch" and "indefinite pitch" ** Absolute pitch or "perfect pitch" ** Pitch class, a set of all pitches that are a whole number of octaves apart ** Relative pitch, the ability to identify a given musical interval between two notes * Pitch accent, a form of accentuation in speech Business * Sales pitch, a line of talk that attempts to persuade someone or something ** Pitch (filmmaking), a proposal for a film ** Elevator pitch, a very short sales presentation, allegedly short enough to be made during an elevator ride Measurement Movement about the transverse axis * Pitch angle (or pitch rotation), one of the angular degrees of freedom of any stiff body (for example a vehicle), describing rotation about the side-to-side axis ** Pitch (aviation), one of the aircraft principal axes of rotation (nose-up or nose-down angle measured from horizontal axis) ** Pitch (ship motion) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coal Dust
Coal dust is a fine powdered form of which is created by the crushing, grinding, or pulverizing of coal. Because of the brittle nature of coal, coal dust can be created during mining, transportation, or by mechanically handling coal. It is a form of fugitive dust. Grinding coal to dust before combusting it improves the speed and efficiency of burning and makes the coal easier to handle. However, coal dust is hazardous to workers if it is suspended in air outside the controlled environment of grinding and combustion equipment. It poses the acute hazard of forming an explosive mixture in air and the chronic hazard of causing pulmonary illness in people who inhale excessive quantities of it. The distribution of the particle-size of coal dust is frequently measured in mesh. The British slang term for cheap fuel consisting of coal dust (slack) containing small lumps of coal (nuts) is nutty slack. Risks The Occupational Safety and Health Administration (OSHA) has set the legal limit (P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sand Rammer
A sand rammer is a piece of equipment used in foundry sand testing to make test specimen of 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 a ... by compacting bulk material by free fixed height drop of fixed weight for 3 times. It is also used to determine compactibility of sands by using special specimen tubes and a linear scale. Mechanism Sand rammer consists of calibrated sliding weight actuated by cam, a shallow cup to accommodate specimen tube below ram head, a specimen stripper to strip compacted specimen out of specimen tube, a specimen tube to prepare the standard specimen of 50 mm diameter by 50 mm height or 2 inch diameter by 2 inch height for an AFS standard specimen.AFS Mould & core test hand book Specimen preparation The cam is actuated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sand Molding
Sand casting, also known as sand molded casting, is a metal casting process characterized by using sand as the mold material. The term "sand casting" can also refer to an object produced via the sand casting process. Sand castings are produced in specialized factories called foundries. Over 60% of all metal castings are produced via sand casting process. Molds made of sand are relatively cheap, and sufficiently refractory even for steel foundry use. In addition to the sand, a suitable bonding agent (usually clay) is mixed or occurs with the sand. The mixture is moistened, typically with water, but sometimes with other substances, to develop the strength and plasticity of the clay and to make the aggregate suitable for molding. The sand is typically contained in a system of frames or mold boxes known as a flask. The mold cavities and gate system are created by compacting the sand around models called patterns, by carving directly into the sand, or by 3D printing. Basic pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
