What Is Brazing Machine?
Brazing machines are used to “braze” metals.
Metal welding methods can be broadly classified into fusion welding, pressure welding, and brazing. Of these, brazing is classified as brazing together with soldering.
Brazing is a method of joining metals (base metal) by melting a brazing agent made of an alloy with a lower melting point than the base metal. Because the temperature is lower than that at which the base metal begins to melt, brazing has the advantage of not distorting the base metal as compared to fusion welding.
Uses of Brazing Machine
Brazing machines are used for brazing metal parts. Two base metals to be joined are placed in a furnace with a brazing agent between them. The temperature inside the machine is raised to a temperature at which the brazing agent melts but the base metal does not, and the brazing is completed after a certain period of time has elapsed and the brazing process is cooled. Since the base metal does not melt in the welding area, unlike fusion welding, a clean joint can be achieved.
When using a brazing machine, the entire base material is heated more evenly than when using a gas burner, so there is no distortion in the joint. This makes it suitable for welding pipe joints and pressure vessels, where airtightness is required. It is also used for automobile parts.
Principle of Brazing Machines
When brazing, brazing agent is placed at or near the joint between the two base materials to be joined. Before doing so, the joint is cleaned with flux, if necessary.
The brazing agent is made of an alloy that has a lower melting temperature than the base metal, most commonly silver brazing agent made of silver mixed with zinc and copper. It is commonly available in bar form, but is also available in plate or paste form. It is silver in color.
Brazing fluid made of copper mixed with zinc has a brass color and is used for joining brass-colored metals. Aluminum brazing filler, also an aluminum alloy, is used for joining aluminum base metals that have a low melting point. When the joint is heated with a burner, the brazing agent melts and spreads over the entire joint surface by capillary action. When cooled, the brazing agent solidifies and the joint is completed.
In brazing using a brazing machine, the base metal with the brazing agent placed in it is placed in a brazing furnace and the inside is heated to a high temperature. The entire piece, including the base metal, is uniformly heated to a temperature that melts the brazing agent but does not melt the base metal.
As a result, the base metal is less distorted than when a gas burner is used, and brazing can be performed more tightly and airtightly. The advantages of this method include the ability to braze multiple pieces at the same time by devising the jig and placement method, and the ability to braze multiple locations at the same time, making it suitable for mass-produced products.