Brazing

Joining metals by flowing a thin layer, capillary thickness, of nonferrous filler metal into the space between them. Brazing temperatures are in excess of 427°C.

Bonding results from the intimate contact produced by the dissolution of a small amount of base metal in the molten filler metal, without fusion of the base metal. Sometimes, the filler metal is put in place as a thin solid sheet or as cladding and the composite is heated as in furnace brazing. The term brazing is used where the temperature exceeds some arbitrary value, such as 430°C.

The term soldering is used for temperatures lower than the arbitrary value.

Arc Brazing

A brazing process wherein the heat is obtained from an electric arc formed between the base metal and an electrode, or between two electrodes.

Block Brazing

A brazing process in which bonding is produced by the heat obtained from heated blocks applied to the parts to be joined and by a nonferrous filler metal having a melting point above 427°C (800°F), but below that of the base metal. The filler metal is distributed in the joint by capillary attraction.

Braze Welding

A method of welding by using a filler metal that liquefies above 450°C (842°F) and below the solid state of the base metals. Unlike brazing, in braze welding, the filler metal is not distributed in the joint by capillary action.

Dip Brazing

A brazing process in which bonding is produced by heating in a molten chemical or metal bath and by using a nonferrous filler metal having a melting point above 427°C (800°F), but below that of the base metals. The filler metal is distributed in the joint by capillary attraction. When a metal bath is used, the bath provides the filler metal.

Film Brazing

A process in which bonding is produced by heating with a molten nonferrous filler metal poured over the joint until the brazing temperature is attained. The filler metal is distributed in the joint by capillary attraction.

Furnace Brazing

A process in which bonding is produced by the furnace heat and a nonferrous filler metal having a melting point above 427°C (800°F), but below that of the base metals. The filler metal is distributed in the joint by capillary attraction.

Hydrogen Brazing

A method of furnace brazing in a hydrogen atmosphere.

Induction Brazing

A process in which bonding is produced by the heat obtained from the resistance of the work to the flow of induced electric current and by using a nonferrous filler metal having a melting point above 427 °C (800 °F), but below that of the base metals. The filler metal is distributed in the joint by capillary attraction.

Resistance Brazing

A brazing process in which bonding is produced by the heat obtained from resistance to the flow of electric current in a circuit of which the workpiece is a part, and by using a nonferrous filler metal having a melting point above 427°C (800°F), but below that of the base metals. The filler metal is distributed in the joint by capillary attraction.

Torch Brazing

A brazing process in which bonding is produced by heating with a gas flame and by using a nonferrous filler metal having a melting point above 427°C (800°F), but below that of the base metal. The filler metal is distributed in the joint of capillary attraction.

See also: Soldering, Welding.