What is Brazing?

Brazing is the process for connecting two metal pieces along with a third molten filler metal. The joining section is heated above the melting point of the filler metal and below that of the metals being joined. Filler metal flows into the gap between the other two metal pieces by capillary motion and results in a strong metallurgical bond after cooling. Since they bear great tensile strength, brazing is considered as a most versatile and highly preferable method.



Brazed joints are unaffected by normal changes in temperature and can withstand shock and vibrations. They possess immense tensile strength. The clean and well finished appearance of brazed joints make brazing the most preferable method for bonding.

Basics of Brazing
The first and foremost thing is to clean the surface of the metal, so that it become free from oils, paints, grease or any other substances. To attain highest strength, proper cleaning should be done with the help of fine steel wool, sand paper. The use of fine abrasive is good for bond strength.

Brazing : The Most Preferred Method
Brazing has been considered as the most common and versatile method for joining two metals. Some of the important features for which it is preferred over other methods are :

• Brazed joints are comparatively stronger
• Highly ductile
• Ideal for joining two dissimilar metals
• Brazing reduces the possibility of warping, overheating or melting the metals being joined
• Economical, as the cost- per-joint is lesser than other methods
• It is highly adaptable to automated methods

Heat Sources
This method of joining two metals require immense of heat. Different brazing processes need different sources of heat.

• Torch Brazing
  A hand held torch provides the heat required for joining the metals.
  
  
• Furnace Brazing
  Furnace provide the required amount of heat to join different metals.
  
  
• Induction Brazing
  Induction coil is used to produce the desired heat in order to join metals.
  
  
• Dip Brazing
  Bonding is produced by heating the metals in molten chemical or molten bath.
  
  
• Resistance Brazing
  The heat is obtained from resistance to the flow of electric current in a circuit.
  
  
• Arc Brazing
  The heat required for brazing is obtained from an electric arc formed between the base metal and an electrode, or between two electrodes.
  
  

Applications of Brazing
Brazing has find its application at various stages of production in a number of industries. Different brazing methods are available for different requirements. Brazing is executed in the manufacturing process of a wide array of products like :

• Jewelry
• Condensers
• Compressors
• Refrigerators
• Mining Tools
• Plumbing Fixtures
• Musical Instruments
• Automotive Applications
• Diesel Engine Circulation Tubes