Engineering Workshop Welding Concepts

Brazing and Soldering Process:Mechanism,Filler rod,Applications

Brazing and Soldering Process: In all the non-fusion welding processes, when the liquid molten metal is poured at the joint, it gets wet and Solidifies. During the process of Solidification, the atoms present on the surface of filler rod are sharing the energy with atoms present on the surface of parent material and thereby it produces the joint.

When the surface atoms are sharing the energy producing the joint it is called as Surface Alloy Joining.

Brazing and Soldering Process:Mechanism,Filler rod,Applications
Brazing and Soldering Process: Mechanism, Filler rod, Applications

Detailed Explanation of Brazing and Soldering Process:

Brazing:

A joining process in which filler metal is placed between the surfaces to be joined. The temperature is raised to melt the filler metal but not the workpiece.

1. The mechanism of the joint is Wetting and Surface Alloying.

  • Joining of two metals without preparing any joint is called as brazing operation.

2. The temperature of the joint must be greater than the melting point of metals. So here in the case of brazing, the temperature of the joint must be greater than 427-degree centigrade.

3.Type of Joint: Permanent

4.Load bearing capability: High

5.Filler Rod: Copper(Cu) Alloys

  • Most commonly used filler rod materials in brazing and braze welding are copper alloys therefore for melting of the filler rod material, Joint must be heated at a temperature greater than 420 or 427-degree centigrade.
  • As there is no joint prepared, the flow of molten metal into the joint is taking place due to capillary action.
  • Due to this, the molten metal of filler rod which is having the highest capillary action will be used as filler rod material.
  • Out of the different metals, the molten metals copper, zinc alloy is having the highest capillary action. hence, it is used as a filler rod in the brazing operation.

Applications of Brazing:

  • Brazing is used for fastening of pipe fittings, carbide tips on tools, heat exchangers, electrical parts, radiators, axles, etc.
  • It can join cast metals to wrought metals, dissimilar metals, porous metal components etc.
  • It is used to join parts of the bicycle such as frame and rims.

 

Soldering:

  1. The mechanism of the joint is Wetting and Surface Alloying.
  2. Type of Joint: Temporary.
  3. Load bearing capability: less than Brazing
  4. The temperature of the joint must be less than the melting point of metals. So here in the case of soldering, the temperature of the joint must be less than 427-degree centigrade.
  5. Filler Rod:(50% lead & 50% Tin Alloy)

When the (50% lead & 50% Tin Alloy) is to be heated to a temperature greater than 427-degree centigrade, the tin present in the lead & Tin alloy starts evaporating. Hence the temperature of the joint must be <427 Degree centigrade.

Applications:

Mostly used to solder the wires on the Printed Circuit Boards(PCB).

This is the complete explanation of Brazing and Welding operations in a detailed way.

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