Glossary of Brazing
aggression / erosion
Excessive alloying can lead to catastrophic effects during brazing. It is primarily a function of time and temperature. Surface dissolution and intergranular attack (IGA) are manifestations.alloying
An interaction between the base metal and filler metal where a minimal dilution of each occurs. This is identified by a migration of elements across the joint interface. Alloying, on a limited scale, is generally beneficial—often increasing joint strength above that obtained by simple wetting. However, it can, based upon chemical compositions, affect corrosion resistance.arc brazing (AB)
A brazing process in which the heat required is obtained from an electric arc.as-brazed
The condition of brazements after brazing and prior to any subsequent thermal, mechanical or chemical treatments.automatic brazing
Brazing with equipment which performs the brazing operation without constant observation and adjustment by a brazing operator. The equipment may or may not perform the loading and unloading of the work. See machine brazing.base material
The material to be welded, brazed, soldered or cut. See also base metal and substrate.base metal
The metal to be welded, brazed, soldered or cut. The use of this term implies that materials other than metals are also referred to, where this is appropriate. See also base material and substrate.base metal test specimens
A test specimen composed wholly of base metal.binder
A liquid material used in the application of powders that cause the powder to compact and stay in place, even after the binder is removed during brazing.blind joint
A joint where no part of it is visible to view.block brazing (BB)
A brazing process in which the heat required is obtained from heated blocks applied to the parts to be joined.bond
A unifying force that holds things together.braze
A bond 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.braze welding
A welding process variation in which a filler metal, having a liquidus above 450 °C (840 °F) and below the solidus of the base metal, is used. Unlike brazing, the filler metal is not distributed in the joint by capillary action.brazeability
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.brazement
An assembly having component parts joined by brazing.brazer
One who performs a manual or semi-automatic brazing operation.brazing (B)
A group of welding processes which produces coalescence of materials by heating them to a suitable temperature 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 laying surfaces of the joint by capillary action.brazing alloy
See preferred term brazing filler metal.brazing filler metal
The metal which fills the capillary gap and has a liquidus above 450 °C (840 °F) but below the solidus of the base materials.brazing operator
One who operates machine or automatic brazing equipment.brazing procedure
The detailed methods and practices including all joint brazing procedures involved in the production of a brazement. See joint brazing procedure.brazing sheet
Brazing filler metal in sheet form, which can be with or without a binder.brazing technique
The details of a brazing operation which, within the limitations of the prescribed brazing procedure, are controlled by the brazer or the brazing operator.brazing temperature
The temperature to which the base metal is heated to enable the filler metal to wet the base metal and form a brazed joint.brazing temperature range
The temperature range within which brazing can be conducted.capillary action
The force by which liquid, in contact with a solid, is distributed between closely fitted facing surfaces of the joint to be brazed or soldered.cement
A viscous liquid, of either a rubber or acrylic base, which acts as both a vehicle and a binder. It is mixed with any powdered filler metal to permit application with a brush, eyedropper, etc. It causes the metal to compact, holding it in place, even after it volatilizes.clad brazing
A metal sheet on which one or both sides are clad (coated) with brazing filler metal. Clad brazing is found most often in aluminum brazing.copper brazing
A term improperly used to denote brazing with copper filler metal. See preferred terms furnace brazing and braze welding.corrosive flux
A flux with a residue that chemically attacks the base metal. It may be composed of inorganic salts and acids, organic salts and acids or activated rosins or resins.dew point
The temperature at which water condenses out of an atmosphere for a given pressure.differential thermal analysis (DTA)
A test procedure for determining the solidus and liquidus temperatures of a material.diffusion bonding
See preferred terms diffusion brazing and diffusion welding.diffusion brazing (DFB)
A brazing process which produces coalescence of metals by heating them to suitable temperatures and by using a filler metal of an in-situ liquid phase. The filler metal may be distributed by capillary attraction or may be placed or formed at the faying surfaces. The filler metal is diffused with the base metal to the extent that the joint properties have been changed to approach those of the base metal. Pressure may or may not be applied.diffusion heat treatment
A thermal cycle, usually performed at 1065 to 1093 °C (1950 to 2000 °F) for two to four hours to cause migration of filler metal suppressants into the base metal. This effectively raises the remelt temperature and strengthens the joint.dip brazing (DB)
A brazing process in which the heat required is furnished by a molten chemical or metal bath. When a molten chemical bath is used, the bath may act as a flux. When a molten metal bath is used, the bath provides the filler metal.electric
brazing See preferred terms resistance brazing and arc brazing.erosion (brazing)
A condition caused by dissolution of the base metal by molten filler metal resulting in a post-braze reduction in the thickness of the base metal.eutectic (1)
An isothermal reversible reaction in which a liquid solution is converted into two or more intimately mixed solids on cooling; the number of solids formed being the same as the number of components in the system. (2) An alloy having the composition indicated by the eutectic point on an equilibrium diagram. (3) An alloy structure of intermixed solid constituents formed by a eutectic reaction. Refer to Silver – Copper Constitutional Diagram, this page.feed side
That external face of an intended joint to which the main reservoir of the filler metal is added prior to the braze operation.filler metal
The metal to be added in making a welded, brazed or soldered joint.fillet
A radiussed area of filler metal at the site where components are joined.fissure
A small crack-like discontinuity with only slight separation (opening displacement) of the fracture surfaces. The prefixes macro or micro indicate relative size.flash
The material which is expelled or squeezed out of a joint.flaw
A near synonym for discontinuity, but with an undesirable connotation.flow brazing (FLB)
A brazing process which produces coalescence of metals by heating them with molten, nonferrous filler metal poured over the joint until brazing temperature is attained. The filler metal is distributed in the joint by capillary attraction.flowability
The ability of molten filler metal to flow or spread over a metal surface.flux
Material used to prevent, dissolve or facilitate removal of oxides and other undesirable surface substances.flux cover
In metal bath dip brazing and dip soldering, a cover of flux over the molten filler metal bath.freezing point
See preferred terms liquidus and solidus.furnace brazing (FB)
A brazing process in which the parts to be joined are placed in a furnace and heated to a suitable temperature.fusion
The melting together of filler metal and base metal (substrate) or of base metal only, which results in coalescence.feed side
That external face of an intended joint to which the main reservoir of the filler metal is added prior to the braze operation.
filler metal
The metal to be added in making a welded, brazed or soldered joint.
fillet
A radiussed area of filler metal at the site where components are joined.fissure
A small crack-like discontinuity with only slight separation (opening displacement) of the fracture surfaces. The prefixes macro or micro indicate relative size.flash
The material which is expelled or squeezed out of a joint.flaw
A near synonym for discontinuity, but with an undesirable connotation.flow brazing (FLB)
A brazing process which produces coalescence of metals by heating them with molten, nonferrous filler metal poured over the joint until brazing temperature is attained. The filler metal is distributed in the joint by capillary attraction.flowability
The ability of molten filler metal to flow or spread over a metal surface.flux
Material used to prevent, dissolve or facilitate removal of oxides and other undesirable surface substances.flux cover
In metal bath dip brazing and dip soldering, a cover of flux over the molten filler metal bath.freezing point
See preferred terms liquidus and solidus.furnace brazing (FB)
A brazing process in which the parts to be joined are placed in a furnace and heated to a suitable temperature.fusion
The melting together of filler metal and base metal (substrate) or of base metal only, which results in coalescence.gap
See joint clearance.gas brazing
See preferred term torch brazing.hard solder
A term erroneously used to denote silver-base brazing filler metals.heat-affected zone (HAZ)
The region of the base metal that has been thermally altered as a result of welding, brazing, soldering or thermal cutting processes.holding time
In brazing and soldering, the amount of time a joint is held within a specified temperature range.hot crack
A crack that develops during solidification.hydrogen brazing
A term erroneously used to denote any brazing process which takes place in a hydrogen or hydrogen- containing atmosphere.inadequate joint penetration
Joint penetration by the braze alloy that is less than specified.incomplete fusion
A condition where all of the braze filler metal in a joint did not melt.induction brazing (IB)
A brazing process in which the heat is obtained from the resistance of the work piece to induced electric current.infrared brazing (IRB)
A brazing process in which the heat is furnished by infrared radiation.infrared radiation
Electromagnetic energy with wavelengths from 770 to 12,000 nanometers.intergranular penetration
The penetration of a filler metal along the grain boundaries of a base metal.joint
The junction of members or the edges of members which are to be joined or have been joined.joint brazing procedure
The materials, detailed methods and practices employed in the brazing of a particular joint.joint clearance
The distance between the mating surfaces of a joint. In brazing, this distance can vary during the brazing process as a result of thermal expansion.joint design
The joint geometry together with the required dimensions.joint efficiency
The ratio of the strength of a joint to the strength of the base metal (expressed in percent).joint geometry
The shape and dimensions of a joint in cross-section prior to brazing.lack of fusion
See preferred term incomplete fusion.lap joint
A joint between two overlapping members.liquation
The separation of the low melting constituent(s) of an alloy from the remaining constituents, which is usually apparent in alloys having a wide melting range. The remaining deposit no longer brazes at the established melting temperature.liquidus
The lowest temperature at which a metal or an alloy is completely liquid.
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