Aluminium Glossary 铝术语表

Term Description AA The Aluminum Association, based in USA is responsible for the industry standard grain refiner (TP-1) and dissolution (TP-2) tests, as well as chemical specifications for master alloys and compacts. AAS Atomic Absorption Spectrometry for chemical analysis especially at low levels. ACFT Alcoa cold finger test assesses grain refiner ability, particularly to predict the onset of twin columnar grains. AFS American Foundrymen"s Society. Agglomeration Term commonly used to describe sticking together of grain refiner particles. AlB2,AlB12 The two possible phases found in BAl master alloys. Al2O3 Alumina or Aluminium oxide. Alloy A mixture containing more than one element. Alloying Element An element that is added to metal to change its physical characteristics and properties. Alumina Aluminium oxide (commonly used to make CFFs and the filtering component of DBFs). Aluminide Phase containing Al plus another element e.g. TiAl3. Aluminium (Aluminum) The 13th element in the periodic table, and the earth"s most abundant metallic element, aluminium was discovered in 1827. Aluminium has an atomic weight of 26.98, a melting point of 660.32°C (1220.576°F), and a boiling point of 2529°C (4566°F). Aluminium is an abundant, light metal with a silvery appearance, used in the manufacture of products requiring light weight, resistance to corrosion and electrical conductivity. Amorphous Glass-like, as in Al alloys developed for studying nucleation. Annealing A heat treatment commonly used to soften an aluminium alloy. Anode Positive electrode made of carbon in electrolytic cells used in the smelting process. Anodizing (also Anodic Oxidation) Coating aluminium by a treatment that creates a thin and extremely hard layer of aluminium oxide on the surface of the metal. Dye-colored coatings can be applied during the process. ASTM American Society for Testing Material. ASTM issues standard specifications on materials, including metals and alloys. Bauxite A soil type and ore derived from the weathering of granite (sialic parent rock), and depleted of nearly all soluble elements. Aluminium oxides are virtually all that remain after calcium, potassium, sodium and silicon have been leached out. Bauxite is the principle ore of aluminium, and is predominantly found in tropical and sub-tropical regions. Billet A cylindrical aluminium ingot used to make extrusions. Carbide Particle containing carbon (e.g. aluminium carbide, titanium carbide). Cathode Negative electrode in electrolytic cells used in the smelting process. Casting Pouring molten metal into moulds at any stage of the fabrication and manufacturing process. CEN Comité Européen de Normalisation is a European equivalent of AA, which has issued chemical specifications for master alloys. CFF Ceramic foam filter, commonly used in the cast house to remove defects from the molten metal stream. CFFs are typically replaced after each casting. Conductivity Ability to conduct electricity. Continuous Casting Term often applied to twin roll casting, where thin strip is cast directly from molten metal. Cryolite Salts-based flux (e.g. potassium aluminium fluoride). DBF Deep bed filters are more complex than CFFs, usually consisting of layers of alumina refractory of different sizes and shapes. DBFs are generally used in much longer campaigns than CFFs. DC Casting Direct-chill casting, a common method used in the wrought industry to produce slabs and billets. Degassing The act of reducing the hydrogen level of molten aluminium. It is often used to also remove inclusions as well as reduce the levels of Na and Ca in the molten aluminium. Dissolution The act of dissolving, especially applied to compacted additives. Drawing or Pressing Forcing a flat metal blank into a die under pressure from a metal ram. This process is used in the manufacture of aluminium "hollowware". Ductility The measure of a material"s ability to deform elastically and plastically without fracturing. Equiaxed Structure The microstructure of a metal in which all grains have approximately the same dimensions in all directions. Eutectic In alloy systems with eutectics, this can be the lowest melting point phase and so the last to solidify when casting. In Al-Si casting alloys, the eutectic is often modified to alter its structure to enhance ductility. Extruding The act of deforming solid aluminium, usually in the form of a cylindrical billet, by pushing it from an enclosed container through a die to form a product of consistent cross section. Filtration Removal of inclusions from the molten metal (see also CFF, DBF). Fines Finest, dusty material. Fluidity Ability to flow and fill a mould. Flux There are several types of fluxes used in the aluminium industry, having different applications, for example to reduce hydrogen gas levels or to remove dross. Forging The act of deforming solid aluminium into either a particular shape by hammering or squeezing in a closed die, or deforming between flat platens. Foundry Term often used to distinguish a producer of shaped castings from a wrought (e.g. billets, slabs) producer. Grain Refiner Al-Ti-B and Al-Ti-C alloys release nucleant particles for grain refining as well as Ti for grain growth restriction. Heat Treatment Method used to alter an alloys properties (e.g. annealing is to soften, whilst other treatments are to harden). Hydrogen The only gas which dissolves to any extent in aluminium. Hypereutectic An alloy whose chemical composition is above that of the eutectic. In hypereutectic Al-Si alloys, the first phase to form on solidification is primary Si. Phosphorus-based additives are often used to refine it. Hypoeutectic An alloy whose chemical composition is below that of the eutectic. In hypoeutectic Al-Si alloys, the first phase to form on solidification is primary Al. Grain refiners are often used to refine it. ICP Inductively Coupled Plasma, combined with optical emission spectrometry is a commonly used technique to determine chemical analysis of master alloys. Ingot Metal cast in a shape that is convenient for handling, storage, shipping and remelting. Ingots may be small enough to be stacked and handled by one person, or in the case of a larger T-ingot, may be designed to be handled by a forklift. Injection A term used for forcing molten metal into a die, also used to describe introduction of powder alloying additives to a furnace of molten metal. ISO International standard for quality system management. KAIF (see PAF) Potassium aluminium fluoride is a flux used in some ALTAB compositions as it enhances dissolution. Also known as PAF. LAIS A technique similar to PoDFA for artificially concentrating the inclusions present in a melt to determine its cleanliness. LiMCA Liquid metal cleanliness analyser is a technique for determining molten metal inclusion levels in a launder in real time. Macs Mini ALTAB charging system is a concept for bulk alloying with minimal handling. Metallography Flat, polished sections of samples are examined under a microscope, typically at magnifications ranging from X50 to X1000. This is called metallography, and is used by grain refiner producers to assess quality. Modification Term applied to refining of the eutectic structure in Al-Si casting alloys. Normally done with Sr, but also Na or Sb used. Oxide Aluminium readily forms oxides which are generally unwanted inclusions. PAF (see KAIF) Potassium aluminium fluoride is a flux used in some ALTAB compositions as it enhances dissolution. Also known as KAIF. PoDFA Porous disc filtration apparatus is a technique to artificially concentrate inclusions present in molten aluminium and so determine cleanliness levels. Poison Term applied to loss of grain refining induced by certain elements, particularly Zr on TiBAl. Porosity The presence of pores in a cast structure. The only gas which dissolves to any extent in aluminium is hydrogen. When molten aluminium is solidified the level of hydrogen that can remain in solution is reduced, so porosity may result. Porous Plug A technique to introduce fluxes or gases into molten aluminium by inserting a plug in the furnace floor. ppi Pores per inch, term applied to describe pore sizes in ceramic foam filters. ppm Parts per million. Process Control The act of controlling the key parameters of a process to try to ensure product consistency. QS The automotive quality management system standard. (QS 9000) Quenching Rapid cooling of a metal from an elevated temperature. Refractory A high melting point material, various refractories exist in the industry with many applications including the direct containment of molten aluminium. RFI Rotary flux injection for injecting flux into a melt. Recovery For an alloying additive this refers to how much of the alloying element in the master alloy or compacted additive ends up in the final alloy. Rolling The act of squeezing between two rollers to form a flat plate, sheet or foil section. Rolling is often first done "hot" to reduce thickness of the cast section in as few passes as possible. "Cold" rolling provide strength benefits as well as being used to achieve final dimensional tolerances. SEM Scanning electron microscopy, used for high magnification study of metal surfaces. Smelting Process of producing molten aluminium by the reduction of alumina. Solubility A measure of how well an additive dissolves in molten aluminium (can also be applied to solid solutions) Spectrometry Method commonly used to determine the chemical composition of an alloy. TEM Transition electron microscopy, used for very high magnification study of internal metallic structures. Thermal Analysis A technique used in foundries to assess how good grain refining will be as well as the eutectic nucleation temperature. It is based on assessing the cooling curve of a solidifying sample. TiAl3 Particle found in TiBAl and TiCAl and TiAl alloys, dissolves in molten Al to play a role in grain growth restriction. TiB2 Particle found in TiBAl alloys, plays a key role in grain refining. TiC Particle found in TiCAl alloys, plays a key role in grain refining. TP-1 The Aluminum Association"s standard test for assessing grain refiner ability. TP-2 The Aluminum Association"s standard test for assessing solubility. Twin Roll Casting See Continuous Casting. Wrought Aluminium Wrought means worked, so can be applied to rolling, extruding and forging.