Brazing and soldering – is a process which entails bonding of metal and non-metal objects with the use of an additional, molten metal, known as filler metal, whose melting temperature is significantly lower that the melting temperature of the bonded metals. Therefore during brazing and soldering they are not melted (as opposed to welding), and the bond is made primarily due to the diffusion of the liquid filler metal into the bonded metals and the other way around, and to a lesser extent – by adhesion.
Brazing – brazing with the use of a filler metal with the liquidus temperature of more than 450° C.
Soldering – brazing with the use of a filler metal with the liquidus temperature of 450° C or less.
High temperature brazing – brazing with the use of a filler metal with the melting temperature of more than 1000 ° C.
Brazing alloy – combination of two or more metals
Soldering filler metals – filler metals with melting temperatures of up to 450 ° C.
Brazing filler metals – filler metals with melting temperatures of more than 450 ° C.
High temperature filler metals – filler metals with the melting temperature of more than 1000 ° C.
Brazed joint / bond – a surface comprising of a zone of melted filler metal and a transition zone.
Capillarity – Capacity of liquid filler metal to fill the brazing gap, even going against gravity.
Wetability – spreading of liquid filler metal on the surface of the element.
Fluidity/ flowing power – Capacity of liquid filler metal to fill the brazing gap, under gravity.
Capillary gap – gap of no more than 0,2 mm at the brazing temperature.
Brazing GAP – narrow gap at the brazing temperature between the brazed elements.
Assembly GAP – narrow gap at room temperature between the elements intended for brazing.
Eutectic alloy – an alloy with, instead of a range of temperatures, one defined melting temperature.
Flux – a substance whose task it is to remove oxides from the surface of the bonded materials occurred due to heating in order to improve wetability
Anti-flux – a substance protecting against unintentional spreading of molten filler metal.
Range of melting temperatures – range of temperatures from the start of the melting process (solidus temperature) to the moment of complete melting (liquidus temperature).
Working temperature – Bond temperature at which wetability occurs by the liquid filler metal. This temperature can be higher or lower than the liquidus temperature for some filler metals may be the same.
Active temperature range – the range of temperatures within which the flux does its job.
Volatile fluxdispenser – a device designed for automatic feed of volatile flux during brazing. The dispenser is filled with liquid flux and installed.
Flame brazing – Thermal bonding of metals process The heat source is the gas flame heating up the brazed bond up to a certain temperature, achieved by oxy-propane, oxy-acetylene, propane and acetylene torches.
Induction brazing – Process of bonding metals where the heat comes from induction on a rapidly changing eddy current electromagnetic field.
Furnace brazing – Process of bonding metals which takes place in specially constructed chamber furnaces in protective active or inert atmospheres or in vacuum.
Solidus temperature – temperature at the lower range of the filler metal melting temperature, which is the lowest filler metal melting temperature.
Liquidus temperature – temperature at the upper range of the filler metal melting temperature, which is the highest filler metal melting temperature.