There are currently 136 terms in this directory
A change in properties of metals and alloys which occurs slowly at room temperature and will proceed rapidly at higher temperatures. The change in properties is often, but not always, due to a phase change (precipitation), but never involves a change in chemical composition of the metal or alloy. See also Age Hardening.
A substance having metallic properties, containing two or more chemical elements, at least one of which is metal. The substance usually has qualities different from those of the individual components.
Acceptable Quality Level. A quality level established on a prearranged system of inspection using samples selected at random.
Binders are added to mold materials in order to create a mold of sufficient hardness. Binders can be either organic or inorganic materials.
Brass is an alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties.
Bronze is principally an alloy of copper and tin. Bronze does not necessarily contain tin, and a variety of alloys of copper, including alloys with arsenic, phosphorus, aluminum, manganese, and silicon, are commonly termed “bronze”. The term is applied to a variety of brasses and the distinction is largely historical.
A foundry operation that is wholly incorporated into a larger manufacturing operation. A captive foundry usually only produces castings for the operation that it is a part of.
A process used to form solid metal shapes out of molten metal. The molten metal is poured into a cavity or a mold.
A small metal insert or spacer used in molds to provide core support during the casting process.
Charpy Impact Test
A pendulum-type single-blow impact test in which the specimen, usually notched, is supported at both ends as a simple beam and broken by a falling pendulum. The energy absorbed in fracture is known as the impact strength or notch toughness.
A metal insert in the sand mold used to produce local chilling and equalize rate of solidification throughout the casting.
Molding sand is mixed with sodium silicate and the mold is gassed with CO2 gas to produce a hard mold or core.
Copper Based Alloys
Alloys that contain copper as their principal ingredient, mainly brass and bronze.
A performed sand aggregate inserted in the mold to shape the interior part of a casting which cannot be shaped by the pattern.
A liquid suspension of a refractory material applied to cores and dried (intended to improve surface of casting).
A ceramic pot or receptacle made of materials such as graphite or silicon carbide, with relatively high thermal conductivity, bonded with clay or carbon, and used in melting metals.
A furnace that melts metals in a refractory crucible. The furnace is typically fueled with coke, oil, gas or electricity.
Taper on the vertical sides of a pattern or corebox that permits the core or pattern to be removed without distorting or tearing of the sand.
1. The act of removing a pattern from the sand mold. 2. A sketch or print that gives the dimensions of a part.
Amount of permanent extension in the vicinity of the fractures in the tensile test; usually expressed as percentage of original gage length.
Specially prepared molding sand mixture used in the mold adjacent to the pattern to produce a smooth casting surface.
A thin section of metal formed at the mold, core, die joint or parting in a casting. Flash usually forms when the cope and drag do not match completely or when the core and the core print do not match.
A metal frame used for making or holding a sand mold. The upper part is the cope and the bottom half is the drag.
A flask that has hinges on one corner and latches opposite that allow the flask to open after the mold is rammed. The same snap flask can then be used for the next mold allowing you to make many molds at a time with just one flask.
Making sand molds from loose or production patterns of such size that they cannot be satisfactorily handled on a bench or molding machine, the equipment being located on the floor during the entire operation of making the mold.
Metal (of known composition) in the form of gates, sprues, runners, risers and scrapped castings returned to the furnace for remelting.
A condition in a casting that occurs when gas is trapped in molten metal or as a result of mold gasses that evolved when the casting was poured.
Moist sand that is bonded by a mixture that contains silica, bentonite clay, carbonaceous material, and water.
Gross Weight of Casting
The weight of the casting which includes the actual product plus the metal in the gating and riser system as poured.
Resistance of a material to indentation as measured by such methods as Brinell, Rockwell, and Vickers. The term hardness also refers to stiffness of a material, or its resistance to scratching, abrasion, or cutting.
A combination of heating and cooling operations that are applied to a metal or alloy to improve its properties and microstructures.
Irregularly shaped fracture in a casting resulting from stresses set up by steep thermal gradients within the casting during solidification.
An element that is allowed into a metal or alloy. Impurities slightly change the properties of the material in some circumstances and can completely damage it in others.
Nonmetallic materials that become part of a metal matrix usually through reoxidation, refractories, slag, and deoxidization products.
Particles of slag, refractory materials, sand or de-oxidation products trapped in the casting during pouring solidification.
Parts formed of a second material placed in the mold before pouring, such as a steel pin that is required to be bonded to an aluminum casting.
A pattern casting process in which a wax or thermoplastic pattern is used. The pattern is invested (surrounded) by a refractory slurry. After the mold is dry, the pattern is melted or burned out of the mold cavity, and molten metal is poured into the resulting cavity.
A jacket is a wood or metal frame which is placed around a mold made in a snap flask during pouring to support the mold and prevent a run out between the cope and drag.
A foundry that creates a wide variety of castings, in small quantities for a range of customers.
A combination machine that employs a jolt action followed by a squeezing action to compact the sand around the pattern.
The name for a variety of receptacles used to move and pour molten metal during the casting process.
The refractory layer of firebrick, clay, sand or other materials that coat the inside of a furnace or ladle.
A projection on a casting that helps maintain alignment of the casting for machining operations.
A casting surface to be used as a basis for measurement in making secondary machining operations.
An engineering drawing which depicts the final size and shape of the part for its end use.
A model of the part to be cast with process shrinkage added from which a metal matchplate can be made.
A plate of metal or other materials on which patterns and gating systems, split along the parting line, are mounted back to back to form an integral piece.
Properties of a material that reveal its strength and elastic behavior. *See also Physical Properties
Metal in the form of sprues, gates, runners, risers and scrapped castings, with known chemical composition that are returned to the furnace for remelting. Sometimes referred to as “revert”.
The difference between the weight of a finished casting and the total weight of the metal poured.
Denotes an irregularity of the casting surface caused by incomplete filling of the mold due to low pouring temperature, gas back-pressure from inadequate venting of the mod, and inadequate gating.
The cavity that the molten metal is poured in to form the final shape. A mold usually consists of a top and bottom piece made of sand or ceramic material.
The impression in a mold produced by removal of the pattern. It is filled with molten metal to form the casting.
Net Weight of Casting
The final weight of a casting that is determined once all of the excess metal from the gating system has been removed.
Molds/cores produced with a resin-bonded air-setting sand. Also known as the airset process because molds are left to harden under normal atmospheric conditions.
A line on a pattern or casting corresponding to the separation between the cope and drag portions of a sand mold.
The wood, metal, foam or plastic replica of the final product to be made. Patterns usually include gating systems.
A craftsman engaged in production of foundry patterns and core boxes from wood, plastic, or metals, such as aluminum, cast iron, etc.
The shrinkage allowance made on all patterns to compensate for the change in dimensions as the solidified casting cools in the mold from freezing temperature of the metal to room temperature. The pattern is made larger by the amount of shrinkage characteristic of the particular metal in the casting and the amount of resulting contraction to be encountered.
The property of a mold material to allow passage of mold/core gases during the pouring of molten metal.
Properties of matter such as density, electrical and thermal conductivity, expansion and specific heat. This term should not be used interchangeably with “mechanical properties.”
Holes in the casting due to: gases trapped in the mold, the reaction of molten metal with moisture in the molding sand, or the imperfect fusion of chaplets with molten metal.
Rapid cooling of hardening; normally achieved by immersion of the object to be hardened in water, oil, or solutions of salt or organic compounds in water.
Packing sand in a mold by raising and dropping the sand, pattern, flask on a table. Jolt squeezers, jarring machines, and jolt rammers are machines using this principle.
The computerized equipment that builds a three-dimensional model of a casting from a CAD drawing.
Ratio of the number of parts scrapped to the total number of parts manufactured, expressed as a percentage or parts per million.
A process for cleaning castings that involves using a metal abrasive that is propelled by centrifugal action.
The portion of the gate assembly that connects the downgate or sprue with the casting ingate or riser. The term also applies to similar portions of master patterns, pattern dies, patterns, investment molds and finished castings.
A set of materials specification issued by the Society of Automotive Engineers, Inc.
A casting made from a pattern produced in a production die to check the accuracy of dimensions and quality of castings that will be made.
Cavities or surface imperfections on a casting caused by sand washing into the mold cavity.
Processing used sand grains into usable forms so that they can be used in the casting process as a replacement for new sand.
Bringing a resin-bonded sand mixture into contact with a pre-heated metal pattern to form a mold.
The process in which clay-free silica sand coated with a thermostatic resin or mixed with resin is placed on a heated metal pattern for a short period of time to form a partially hardened shell. The bulk of the sand mixture inside the resulting shell is removed for further use. The pattern and shell are heated further to harden or polymerize the resin-sand mix, and the shell is removed from the pattern. Frequently, shell cores are made using this process.
A process for cleaning castings that involves using a metal abrasive that is propelled by centrifugal or air force. See also Rotoblasting.
A cavity that forms in a metal part when there was not enough source metal fed into the mold during the casting process.
A device used by pattern makers. It appears to be a regular ruler, but the graduations are oversized to make up for the shrink in the metal poured. Shrink rules are specific to the metal being cast, due to different metal having different shrink rates.
The contraction of metal in the mold during solidification. The term also is used to describe the casting defect, such as shrinkage cavity, which results from poor design, insufficient metal feed or inadequate feeding.
Removing or hold back dirt or slag from the surface of the molten metal before or during pouring.
A film that forms on top of molten metal as a result of impurities. Slag is composed of non-metal elements.
The watery mixture such as the gypsum mixture for plaster molding, the molding medium used for investment casting, core dips, and mold washes.
A heat treatment to reduce residual stresses followed by sufficiently slow cooling to minimize development of new residual stresses.
The maximum stress in uniaxial tension testing which a material will withstand prior to fracture. The ultimate tensile strength is calculated from the maximum load applied during the test divided by the original cross-sectional area.
Standard specimen bar designed to permit determination of mechanical properties of the metal from which it was poured.
Thermocouples are used to measure temperature by using two dissimilar metals welded at the end.