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A nonferrous bearing alloy originated by Isaac Babbitt in 1839. Currently, the term includes several tin-base alloys consisting mainly of various amounts of copper, antimony, tin, and lead. Lead-base Babbitt metals are also used.
A reverse taper on a casting pattern or a forging die that prevents the pattern or forged stock from being removed from the cavity.
The momentary recession of the flame into the welding tip or cutting tip followed by immediate reappearance or complete extinction of the flame. See also flashback.
The removal of weld metal and base metal from the other side of a partially welded joint to facilitate complete fusion and complete joint penetration upon subsequent welding from that side.
(1) In grinding, the material (paper, cloth, or fiber) that serves as the base for coated abrasives. (2) In welding, a material placed under or behind a joint to enhance the quality of the weld at the root. It may be a metal backing ring or strip; a pass of weld metal; or a nonmetal such as carbon, granular flux, or a protective gas. (3) In plain bearings, that part of the bearing to which the bearing alloy is attached, normally by a metallurgical bond.
A rapid withdrawal of a grinding wheel or cutting tool from contact with a workpiece.
Same as indirect extrusion . See extrusion.
A metastable aggregate of ferrite and cementite resulting from the transformation of austenite at temperatures below the pearlite range but above Ms, the martensite start temperature. Upper bainite is an aggregate that contains parallel lath-shape units of ferrite, produces the so-called “feathery” appearance in optical microscopy, and is formed above approximately 350 °C (660 °F). Lower bainite, which has an acicular appearance similar to tempered martensite, is formed below approximately 350 °C (660 °F).
Quench-hardening treatment resulting principally in the formation of bainite.
A proprietary name for a phenolic thermosetting resin used as a plastic mounting material for metallographic samples.
(1) Heating to a low temperature in order to remove gases. (2) Curing or hardening surface coatings such as paints by exposure to heat. (3) Heating to drive off moisture, as in baking of sand cores after molding.
(1) Same as ball sizing . (2) Removing burrs and polishing small stampings and small machined parts by tumbling in the presence of metal balls.
A machine consisting of a rotating hollow cylinder partly filled with metal balls (usually hardened steel or white cast iron) or sometimes pebbles; used to pulverize crushed ores or other substances such as pigments or ceramics.
A method of grinding and mixing material, with or without liquid, in a rotating cylinder or conical mill partially filled with grinding media such as balls or pebbles.
Sizing and finishing a hole by forcing a ball of suitable size, finish, and hardness through the hole or by using a burnishing bar or broach consisting of a series of spherical lands of gradually increasing size coaxially arranged. Also called ball burnishing , and sometimes ball broaching.
A segregated structure consisting of alternating nearly parallel bands of different composition, typically aligned in the direction of primary hot working.
Inhomogeneous distribution of alloying elements or phases aligned in filaments or plates parallel to the direction of working. See also banded structure , ferrite-pearlite banding , and segregation banding.
An indentation in carbon steel or strip caused by external pressure on the packaging band around cut lengths or coils; it may occur in handling, transit, or storage.
Hot-rolled steel strip, usually produced for rerolling into thinner sheet or strip. Also known as hot bands or band steel.
(1) A section hot rolled from a billet to a form, such as round, hexagonal, octagonal, square, or rectangular, with sharp or rounded corners or edges and a cross-sectional area of less than 105 cm2 (16 in.2). (2) A solid section that is long in relationship to its cross-sectional dimensions, having a completely symmetrical cross section and a width or greatest distance between parallel faces of 9.5 mm ( in.) or more. (3) An obsolete unit of pressure equal to 100 kPa.
A filler metal electrode consisting of a single metal or alloy that has been produced into a wire, strip, or bar form and that has had no coating or covering applied to it other than that which was incidental to its manufacture or preservation.
A machine in which a folding bar or wing is used to bend a metal sheet whose edge is clamped between the upper folding leaf and the lower stationary jaw into a narrow, sharp, close, and accurate fold along the edge. It is also capable of making rounded folds such as those used in wiring. A universal folder is more versatile in that it is limited to width only by the dimensions of the sheet.
The sequence of abrupt changes in magnetic induction occurring when the magnetizing force acting on a ferromagnetic specimen is varied.
Mechanical or electrolytic cleaning of metal in rotating equipment.
Improving the surface finish of workpieces by processing them in rotating equipment along with abrasive particles that may be suspended in a liquid. The barrel is normally loaded about 60% full with a mixture of parts, media, compound, and water.
Convexity of the surfaces of cylindrical or conical bodies, often produced unintentionally during upsetting or as a natural consequence during compression testing.
Plating articles in a rotating container, usually a perforated cylinder that operates at least partially submerged in a solution.
Same as bar.
(1) A chemical substance that yields hydroxyl ions (OH) when dissolved in water. Compare with acid . (2) The surface on which a single-point tool rests when held in a tool post. Also known as heel. (3) In forging, see anvil.
(1) The metal present in the largest proportion in an alloy; brass, for example, is a copper-base alloy. (2) The metal to be brazed, cut, soldered, or welded. (3) After welding, that part of the metal that was not melted. (4) A metal that readily oxidizes or that dissolves to form ions. Contrast with noble metal (2).
basic bottom and lining
The inner bottom and lining of a melting furnace, consisting of materials such as crushed burned dolomite, magnesite, magnesite bricks, or basic slag that give a basic reaction at the operating temperature.
basic oxygen furnace
A large tiltable vessel lined with basic refractory material that is a type of furnace for modern steelmaking. After the furnace is charged with molten pig iron (which usually comprises 65 to 75% of the charge), scrap steel, and fluxes, a lance is brought down near the surface of the molten metal and a jet of high-velocity oxygen impinges on the metal. The oxygen reacts with carbon and other impurities in the steel to form liquid compounds that dissolve in the slag and gases that escape from the top of the vessel.
Refractories whose major constituent is lime, magnesia, or both, and which may react chemically with acid refractories, acid slags, or acid fluxes at high temperatures. Basic refractories are used for furnace linings. Compare with acid refractory.
Steel melted in a furnace with a basic bottom and lining and under a slag containing an excess of a basic substance such as magnesia or lime.
See preferred term substrate.
A quantity of materials formed during the same process or in one continuous process and having identical characteristics throughout. See also lot.
A furnace used to heat treat a single load at a time. Batch-type furnaces are necessary for large parts such as heavy forgings and are preferred for complex alloy grades requiring long cycles.
The phenomenon by which plastic deformation increases yield strength in the direction of plastic flow and decreases it in other directions.
A whitish to reddish mineral composed largely of hydrates of alumina having a composition of Al2O3·2H2O. It is the most important ore (source) of aluminum, alumina abrasives, and alumina-base refractories.
A process for extracting alumina from bauxite ore before the electrolytic reduction. The bauxite is digested in a solution of sodium hydroxide, which converts the alumina to soluble aluminate. After the “red mud” residue has been filtered out, aluminum hydroxide is precipitated, filtered out, and calcined to alumina.
Macroscopic progression marks on a fatigue fracture or stress-corrosion cracking surface that indicate successive positions of the advancing crack front. The classic appearance is of irregular elliptical or semielliptical rings, radiating outward from one or more origins. Beach marks (also known as clamshell marks or arrest marks) are typically found on service fractures where the part is loaded randomly, intermittently, or with periodic variations in mean stress or alternating stress. See also striation.
(1) Half-round cavity in a mold, or half-round projection or molding on a casting. (2) A single deposit of weld metal produced by fusion.
A flange reinforced by a low ridge, used mostly around a hole.
Raising a ridge or projection on sheet metal.
See preferred term surfacing weld.
The maximum bearing stress that can be sustained. Also, the bearing stress at that point on the stress-strain curve at which the tangent is equal to the bearing stress divided by n% of the bearing hole diameter.
The shear load on a mechanical joint (such as a pinned or riveted joint) divided by the effective bearing area. The effective bearing area of a riveted joint, for example, is the sum of the diameters of all rivets times the thickness of the loaded member.
A method of determining the response to stress (load) of sheet products that are subjected to riveting, bolting, or a similar fastening procedure. The purpose of the test is to determine the bearing strength of the material and to measure the bearing stress versus the deformation of the hole created by a pin or rod of circular cross section that pierces the sheet perpendicular to the surface.
(1) The stationary portion of a press structure that usually rests on the floor or foundation, forming the support for the remaining parts of the press and the pressing load. The bolster and sometimes the lower die are mounted on the top surface of the bed. (2) For machine tools, the portion of the main frame that supports the tool, the work, or both. (3) Stationary part of the shear frame that supports the material being sheared and the fixed blade.
A layer of metal disturbed by mechanical working, wear, or mechanical polishing presumed to be without regular crystalline structure (amorphous); originally applied to grain boundaries.
A continuous-type furnace that uses a mesh-type or cast-link belt to carry parts through the furnace.
Grinding with an abrasive belt.
Casting sand molds by hand tamping loose or production patterns at a bench without the assistance of air or hydraulic action.
The length of the arc of the neutral axis between the tangent points of a bend.
The angle through which a bending operation is performed, that is, the supplementary angle to that formed by the two bend tangent lines or planes.
The straining of material, usually flat sheet or strip metal, by moving it around a straight axis lying in the neutral plane. Metal flow takes place within the plastic range of the metal, so that the bent part retains a permanent set after removal of the applied stress. The cross section of the bend inward from the neutral plane is in compression; the rest of the bend is in tension.
A form of open-frame single-action press that is comparatively wide between the housings, with a bed designed for holding long, narrow forming edges or dies. Used for bending and forming strip, plate, and sheet (into boxes, panels, roof decks, and so on). Also known as press brake.
Dies used in presses for bending sheet metal or wire parts into various shapes. The work is done by the punch pushing the stock into cavities or depressions of similar shape in the die or by auxiliary attachments operated by the descending punch.
The algebraic sum of the couples or the moments of the external forces, or both, to the left or right of any section on a member subjected to bending by couples or transverse forces, or both.
Various types of machinery equipped with two or more rolls to form curved sheet and sections.
bend or twist (defect)
Distortion similar to warpage generally caused during forging or trimming operations. When the distortion is along the length of the part, it is termed bend; when across the width, it is termed twist. When bend or twist exceeds tolerance, it is considered a defect. Corrective action consists of hand straightening, machine straightening, or cold restriking.
(1) The inside radius of a bend section. (2) The radius of a tool around which metal is bent during fabrication.
A tangent point at which a bending arc ceases or changes.
A test for determining relative ductility of metal that is to be formed (usually sheet, strip, plate, or wire) and for determining soundness and toughness of metal (after welding, for example). The specimen is usually bent over a specified diameter through a specified angle for a specified number of cycles.
Concentration or other preparation of ore for smelting.
A colloidal claylike substance derived from the decomposition of volcanic ash composed chiefly of the minerals of the montmorillonite family. It is used for bonding molding sand.
A process for making steel by blowing air through molten pig iron contained in a refractory lined vessel so as to remove by oxidation most of the carbon, silicon, and manganese. This process is essentially obsolete in the United States.
beta () ray
A ray of electrons emitted during the spontaneous disintegration of certain atomic nuclei.
beta () structure
A Hume-Rothery designation for structurally analogous body-centered cubic phases (similar to brass) or electron compounds that have ratios of three valence electrons to two atoms. Not to be confused with a phase on a phase diagram.
An angular edge preparation in a weld member.
Same as flaring.
In a biaxial stress state, the ratio of the smaller to the larger principal stress.
A state of stress in which only one of the principal stresses is zero, the other two usually being in tension.
(1) A semifinished section that is hot rolled from a metal ingot, with a rectangular cross section usually ranging from 105 to 230 cm2 (16 to 36 in.2), the width being less than twice the thickness. Where the cross section exceeds 230 cm2 (36 in.2), the term bloom is properly but not universally used. Sizes smaller than 105 cm2 (16 in.2) are usually termed bars. (2) A solid semifinished round or square product that has been hot worked by forging, rolling, or extrusion. See also bar.
A primary rolling mill used for making steel billets.
An alloy containing only two component elements.
The complete series of compositions produced by mixing a pair of components in all proportions.
(1) In founding, a material, other than water, added to foundry sand to bind the particles together, sometimes with the use of heat. (2) In powder technology, a cementing medium: either a material added to the powder to increase the green strength of the compact, which is expelled during sintering; or a material (usually of relatively low melting point) added to a powder mixture for the specific purpose of cementing together powder particles that alone would not sinter into a strong body.
A metal used as a binder. An example would be cobalt in cemented carbides.
Deterioration of metals as a result of the metabolic activity of microorganisms. Also known as biofouling.
An electrode in an electrolytic cell that is not mechanically connected to the power supply, but is so placed in the electrolyte, between the anode and cathode, that the part nearer the anode becomes cathodic and the part nearer the cathode becomes anodic. Also called intermediate electrode.
A longitudinal magnetic field that creates two magnetic poles within a piece of material. Compare with circular field.
Box annealing or pot annealing ferrous alloy sheet, strip, or wire impart a black color to the oxidized surface. See also box annealing.
See malleable iron.
Carbonaceous materials, such as graphite or powdered carbon, usually mixed with a binder and frequently carried in suspension in water or other liquid used as a thin facing applied to surfaces of molds or cores to improve casting finish.
A black finish on a metal produced by immersing it in hot oxidizing salts or salt solutions.
(1) In forming, a piece of sheet metal, produced in cutting dies, that is usually subjected to further press operations. (2) A pressed, presintered, or fully sintered powder metallurgy compact, usually in the unfinished condition and requiring cutting, machining, or some other operation to produce the final shape. (3) A piece of stock from which a forging is made, often called a slug or multiple.
Simulating the carburizing operation without introducing carbon. This is usually accomplished by using an inert material in place of the carburizing agent, or by applying a suitable protective coating to the ferrous alloy.
(1) The part of a drawing or forming die that holds the workpiece against the draw ring to control metal flow. (2) The part of a drawing or forming die that restrains the movement of the workpiece to avoid wrinkling or tearing of the metal.
The operation of punching, cutting, or shearing a piece out of stock to a predetermined shape.
Simulating the nitriding operation without introducing nitrogen. This is usually accomplished by using an inert material in place of the nitriding agent or by applying a suitable protective coating to the ferrous alloy.
A shaft furnace in which solid fuel is burned with an air blast to smelt ore in a continuous operation. Where the temperature must be high, as in the production of pig iron, the air is preheated. Where the temperature can be lower, as in smelting of copper, lead, and tin ores, a smaller furnace is economical, and preheating of the blast is not required.
blasting or blast cleaning
A process for cleaning or finishing metal objects with an air blast or centrifugal wheel that throws abrasive particles against the surface of the workpiece. Small, irregular particles of metal are used as the abrasive in gritblasting; sand, in sandblasting; and steel, in shotblasting.
A mixture of sands of different grain size and clay content that provides suitable characteristics for foundry use.
In powder metallurgy, the thorough intermingling of powders of the same nominal composition (not to be confused with mixing).
A riser that does not extend through the top of the mold.
(1) A casting defect, on or near the surface of the metal, resulting from the expansion of gas in a subsurface zone. It is characterized by a smooth bump on the surface of the casting and a hole inside the casting directly below the bump. (2) A raised area, often dome shaped, resulting from loss of adhesion between a coating or deposit and the substrate.
An impure intermediate product in the refining of copper, produced by blowing copper matte in a converter, the name being derived from the large blisters on the cast surface that result from the liberation of SO2 and other gases.
A preliminary forging operation that roughly distributes metal preparatory for finish.
block and finish
The forging operation in which a part to be forged is blocked and finished in one heat through the use of tooling having both a block impression and a finish impression in the same die block.
The impression in the dies (often one of a series of impressions in a single die set) that imparts to the forging an intermediate shape, preparatory to forging of the final shape. Also called blocking impression.
Forging dies having generous contours, large radii, draft angles of 7° or more, and liberal finish allowances. See also finish allowance.
A forging that approximates the general shape of the final part with relatively generous finish allowance and radii. Such forgings are sometimes specified to reduce die costs where only a small number of forgings are described and the cost of machining each part to its final shape is not excessive.
In forging, a preliminary operation performed in closed dies, usually hot, to position metal properly so that in the finish operation the dies will be filled correctly. Blocking can ensure proper working of the material and can increase die life.
Same as blocker.
(1) A semifinished hot-rolled product, rectangular in cross section, produced on a blooming mill. See also billet . For steel, the width of a bloom is not more than twice the thickness, and the cross-sectional area is usually not less than about 230 cm2 (36 in.2). Steel blooms are sometimes made by forging. (2) A visible exudation or efflorescence on the surface of an electroplating bath. (3) A bluish fluorescent cast to a painted surface caused by deposition of a thin film of smoke, dust, or oil. (4) A loose, flowerlike corrosion product that forms when certain metals are exposed to a moist environment.
A primary rolling mill used to make blooms.
A hole in a casting or a weld caused by gas entrapped during solidification. See also porosity .
Heating hot-rolled ferrous sheet in an open furnace to a temperature within the transformation range, then cooling in air to soften the metal. A bluish oxide surface layer forms.
Brittleness exhibited by some steels after being heated to some temperature within the range of about 205 to 370 °C (400 to 700 °F), particularly if the steel is worked at the elevated temperature. Killed steels are virtually free of this kind of brittleness.
Subjecting the scale-free surface of a ferrous alloy to the action of air, steam, or other agents at a suitable temperature, thus forming a thin blue film of oxide and improving the appearance and resistance to corrosion. This term is ordinarily applied to sheet, strip, or finished parts. It is used also to denote the heating of springs after fabrication to improve their properties.
A type of forging hammer in which the upper die and ram are attached to “boards” that are raised to the striking position by power-driven rollers and let fall by gravity. See also gravity hammer.
A plate to which dies may be fastened, the assembly being secured to the top surface of a press bed. In mechanical forging, such a plate is also attached to the ram.
(1) In grinding wheels and other relatively rigid abrasive products, the material that holds the abrasive grains together. (2) In welding, brazing, or soldering, the junction of joined parts. Where filler metal is used, it is the junction of the fused metal and the heat-affected base metal. (3) In an adhesive-bonded or diffusion-bonded joint, the line along which the faying surfaces are joined together. (4) In thermal spraying, the junction between the material deposited and the substrate, or its strength.
A split permanent mold hinged like a book.
A hole or cylindrical cavity produced by a single-point or multipoint tool other than a drill.
Thermochemical treatment involving the enrichment of the surface layer of an object with borides. This surface-hardening process is performed below the Ac1 temperature. Also referred to as boronizing.
Enlarging a hole by removing metal with a single- or occasionally a multiple-point cutting tool moving parallel to the axis of rotation of the work or tool.
(1) Natural diamond of a quality not suitable for gem use. (2) Industrial diamond.
(1) The section of a blast furnace extending upward from the tuyeres to the plane of maximum diameter. (2) A lining of quartz that builds up during the smelting of copper ores and that decreases the diameter of the furnace at the tuyeres. (3) A tank, often with sloping sides, used for washing metal parts or for holding cleaned parts.
A relatively short protrusion or projection from the surface of a forging or casting, often cylindrical in shape. Usually intended for drilling and tapping for attaching parts.
In casting, a flat base for holding the flask in making sand molds.
A flat-ended twist drill used to convert a cone at the bottom of a drilled hole into a cylinder.
A tap with a chamfer of 1 to 1 threads in length.
An oxide-lined fold or cavity at the butt end of a slab, bloom, or billet; formed by folding the end of an ingot over on itself during primary rolling. Bottom pipe is not pipe, in that it is not a shrinkage cavity, and in that sense, the term is a misnomer. Bottom pipe is similar to extrusion pipe. It is normally discarded when the slab, bloom, or billet is cropped following primary reduction.
Deviation from flatness.
Annealing a metal or alloy in a sealed container under conditions that minimize oxidation. In box annealing a ferrous alloy, the charge is usually heated slowly to a temperature below the transformation range, but sometimes above or within it, and is then cooled slowly; this process is also called close annealing or pot annealing. See also black annealing.
The continuation of a fillet weld around a corner of a member as an extension of the principal weld.
A device for bending sheet metal to a desired angle.
A conical 120° diamond indenter with a conical tip (a 0.2 mm tip radius is typical) used in certain types of Rockwell and scratch hardness tests.
A copper-zinc alloy containing up to 40% Zn, to which smaller amounts of other elements may be added.
A weld produced by heating an assembly to suitable temperatures and by using a filler metal having a liquidus above 450 °C (840 °F) and below the solidus of the base metal. The filler metal is distributed between the closely fitted faying surfaces of the joint by capillary action.
The capacity of a metal to be brazed under the fabrication conditions imposed into a specific suitably designed structure and to perform satisfactorily in the intended service.
A method of welding by using a filler metal having a liquidus above 450 °C (840 °F) and below the solidus of the base metals. Unlike brazing, in braze welding, the filler metal is not distributed in the joint by capillary attraction.
A group of welding processes that join solid materials together by heating them to a suitable temperature and using a filler metal having a liquidus above 450 °C (840 °F) and below the solidus of the base materials. The filler metal is distributed between the closely fitted surfaces of the joint by capillary attraction.
See preferred term brazing filler metal.
brazing filler metal
(1) The metal that fills the capillary gap and has a liquidus above 450 °C (840 °F) but below the solidus of the base materials. (2) A nonferrous filler metal used in brazing and braze welding.
Brazing filler metal in sheet form.
(1) An initial rolling or drawing operation, or a series of such operations, for the purpose of reducing a casting or extruded shape prior to the finish reduction to desired size. (2) A preliminary press-forging operation.
Same as fracture stress (1).
Creases or ridges usually in “untempered” or in aged material where the yield point has been exceeded. Depending on the origin of the breaks, they may be termed cross breaks , coil breaks , edge breaks, or sticker breaks.
A two-section extrusion die capable of producing tubing or intricate hollow shapes without the use of a separate mandrel. Metal separates into two streams as it is extruded past a bridge section, which is attached to the main die section and holds a stub mandrel in the die opening; the metal then is rewelded by extrusion pressure before it enters the die opening.
(1) Premature solidification of metal across a mold section before the metal below or beyond solidifies. (2) Solidification of slag within a cupola at or just above the tuyeres. (3) Welding or mechanical locking of the charge in a downfeed melting or smelting furnace. (4) In powder metallurgy, the formation of arched cavities in a powder mass. (5) In soldering, an unintended solder connection between two or more conductors, either securely or by mere contact. Also called a crossed joint or solder short.
Annealing in a protective medium to prevent discoloration of the bright surface.
A solution that produces, through chemical action, a bright surface on an immersed metal.
An agent or combination of agents added to an electroplating bath to produce a lustrous deposit.
A high-quality finish produced on ground and polished rolls. Suitable for electroplating.
Nitriding in a protective medium to prevent discoloration of the bright surface. Compare with blank nitriding.
An electrodeposit that is lustrous in the as-plated condition.
Brinell hardness number (HB)
A number related to the applied load and to the surface area of the permanent impression made by a ball indenter computed from: where F is the test force, N; D is diameter of ball, mm; and d is mean diameter of the impression, mm.
Brinell hardness test
A test for determining the hardness of a material by forcing a hard steel or carbide ball of specified diameter (typically, 10 mm) into it under a specified load. The result is expressed as the Brinell hardness number.
(1) Indentation of the surface of a solid body by repeated local impact or impacts, or static overload. Brinelling may occur especially in a rolling-element bearing. (2) Damage to a solid bearing surface characterized by one or more plastically formed indentations brought about by overload. See also false brinelling.
A quench in which brine (salt water-chlorides, carbonates, and cyanides) is the quenching medium. The salt addition improves the efficiency of water at the vapor phase or hot stage of the quenching process.
brittle crack propagation
A very sudden propagation of a crack with the absorption of no energy except that stored elastically in the body. Microscopic examination may reveal some deformation even though it is not noticeable to the unaided eye. Contrast with ductile crack propagation.
Separation of a solid accompanied by little or no macroscopic plastic deformation. Typically, brittle fracture occurs by rapid crack propagation with less expenditure of energy than for ductile fracture. Brittle tensile fractures have a bright, granular appearance and exhibit little or no necking. A chevron pattern may be present on the fracture surface, pointing toward the origin of the crack, especially in brittle fractures in flat platelike components. Examples of brittle fracture include transgranular cracking (cleavage and quasi-cleavage fracture) and intergranular cracking (decohesive rupture).
The tendency of a material to fracture without first undergoing significant plastic deformation. Contrast with ductility.
Cutting with a tool that consists of a bar having a single edge or a series of cutting edges (i.e., teeth) on its surface. The cutting edges of multiple-tooth, or successive single-tooth, broaches increase in size and/or change in shape. The broach cuts in a straight line or axial direction when relative motion is produced in relation to the workpiece, which may also be rotating. The entire cut is made in single or multiple passes over the workpiece to shape the required surface contour.
A copper-rich copper-tin alloy with or without small proportions of other elements such as zinc and phosphorus. By extension, certain copper-base alloys containing considerably less tin than other alloying elements, such as manganese bronze (copper-zinc plus manganese, tin, and iron) and leaded tin bronze (copper-lead plus tin and sometimes zinc). Also, certain other essentially binary copper-base alloys containing no tin, such as aluminum bronze (copper-aluminum), silicon bronze (copper-silicon), and beryllium bronze (copper-beryllium). Also, trade designations for certain specific copper-base alloys that are actually brasses, such as architectural bronzes (57 Cu, 40 Zn, 3 Pb) and commercial bronze (90 Cu, 10 Zn).
(1) Applying a chemical finish to copper or copper-alloy surfaces to alter the color. (2) Plating a copper-tin alloy on various materials.
An anodizing process similar to brush plating.
Plating with a concentrated solution or gel held in or fed to an absorbing medium, pad, or brush carrying the anode (usually insoluble). The brush is moved back and forth over the area of the cathode to be plated.
(1) Bulging of a large, flat face of a casting; in investment casting, caused by dip coat peeling from the pattern. (2) An indentation in a casting, resulting from expansion of the sand, can be termed the start of an expansion defect. (3) A local waviness in metal bar or sheet, usually transverse to the direction of rolling.
(1) A mode of failure generally characterized by an unstable lateral material deflection due to compressive action on the structural element involved. (2) In metal forming, a bulge, bend, kink, or other wavy condition of the workpiece caused by compressive stresses. See also compressive stress.
(1) A substance that by its addition or presence tends to minimize the physical and chemical effects of one or more of the substances in a mixture. Properties often buffered include pH, oxidation potential, and flame or plasma temperatures. (2) A substance whose purpose is to maintain a constant hydrogen-ion concentration in water solutions, even where acids or alkalis are added. Each buffer has a characteristic limited range of pH over which it is effective.
Developing a lustrous surface by contacting the work with a rotating buffing wheel.
Buff sections assembled to the required face width for use on a rotating shaft between flanges. Sometimes called a buff.
(1) A weld surfacing variation in which surfacing metal is deposited to achieve the required dimensions. See also buttering . (2) Excessive electrodeposition that occurs on high-current-density areas, such as corners or edges.
(1) Chip material adhering to the tool face adjacent to the cutting edge during cutting. (2) Material from the workpiece, especially in machining, which is stationary with respect to the tool.
(1) Expanding the walls of a cup, shell, or tube with an internally expanded segmented punch or a punch composed of air, liquids, or semiliquids such as waxes, rubber, and other elastomers. (2) The process of increasing the diameter of a cylindrical shell (usually to a spherical shape) or of expanding the outer walls of any shell or box shape whose walls were previously straight.
Forming processes, such as extrusion, forging, rolling, and drawing, in which the input material is in billet, rod, or slab form and a considerable increase in surface-to-volume ratio in the formed part occurs under the action of largely compressive loading. Compare with sheet forming.
bulk modulus of elasticity (K)
The measure of resistance to change in volume; the ratio of hydrostatic stress to the corresponding unit change in volume. This elastic constant can be expressed by: where K is the bulk modulus of elasticity, m is hydrostatic or mean stress tensor, p is hydrostatic pressure, and is compressibility. Also known as bulk modulus, compression modulus, hydrostatic modulus, and volumetric modulus of elasticity.
A machine with a power-driven revolving drum for cold drawing wire through a drawing die as the wire winds around the drum.
Slow-acting horizontal mechanical press with a large bed used for bending and straightening. The work is done between dies and can be performed hot or cold. The machine is closely allied to a forging machine.
(1) A semirefined alloy containing sufficient precious metal to make recovery profitable. (2) Refined gold or silver, uncoined.
The microstructure of malleable or ductile cast iron when graphite nodules are surrounded by a ferrite layer in a pearlitic matrix.
A machine used for packing molding sand in a flask by repeated jarring or jolting. See also jolt ramming.
(1) Forming a dish in metal by means of many repeated blows. (2) Forming a head. (3) Setting the seams on sheet metal parts. (4) Ramming sand in a flask by repeated jarring and jolting.
A dull, nodular electrodeposit resulting from excessive plating current density.
A defect consisting of a mixture of sand and metal cohering to the surface of a casting.
A mixture of sand and cast metal adhering to the surface of a casting. In some instances, may resemble metal penetration.
See burned deposit.
(1) Permanently damaging a metal or alloy by heating to cause either incipient melting or intergranular oxidation. See also overheating . (2) During subcritical annealing, particularly in continuous annealing, production of a severely decarburized and grain-coarsened surface layer that results from excessively prolonged heating to an excessively high temperature. (3) In grinding, getting the work hot enough to cause discoloration or to change the microstructure by tempering or hardening. (4) In sliding contacts, the oxidation of a surface due to local heating in an oxidizing environment.
Finish sizing and smooth finishing of surfaces (previously machined or ground) by displacement, rather than removal, of minute surface irregularities with smooth-point or line-contact fixed or rotating tools.
(1) Unintentional removal of an autocatalytic deposit from a nonconducting substrate, during subsequent electroplating operations, owing to the application of excessive current or a poor contact area. (2) Removal of volatile lubricants such as metallic stearates from metal powder compacts by heating immediately prior to sintering.
(1) A thin ridge or roughness left on a workpiece (e.g., forgings or sheet metal blanks) resulting from cutting, punching, or grinding. (2) A rotary tool having teeth similar to those on hand files.
Same as deburring.
A bearing or guide.
A pair of shaped dies used to combine preliminary forging operations, such as edging and blocking, or to loosen scale.
A semilustrous metal finish composed of fine, uniformly distributed parallel lines, usually produced with a soft abrasive buffing wheel; similar in appearance to the traditional hand-rubbed finish on silver.
A form of surfacing in which one or more layers of weld metal are deposited on the groove face of one member (for example, a high-alloy weld deposit on steel base metal that is to be welded to a dissimilar base metal). The buttering provides a suitable transition weld deposit for subsequent completion of the butt weld (joint).
(1) A globule of metal remaining in an assaying crucible or cupel after fusion has been completed. (2) That part of a weld that tears out in destructive testing of a spot, seam, or projection welded specimen.