Advantages, Disadvantages, Precautions in Brazing

Advantages of Brazing

Following are the advantages of brazing:

(a) Brazing is used to join a large variety of dissimilar metals.

(b) Properly brazed joints are pressure tight.

(c) Pieces having great difference in cross-sectional areas can be brazed.

(d) Thin sheets, pipes and gauges that can’t be joined by welding can be joined by brazing.

(e) Complex assemblies can be fabricated by this method.

(f) A brazed component has ability to preserve protective metal coating.

(g) Brazing can be done on cast and wrought materials.

(h) Corrosion resistance joints can be produced by this method.

(j) Brazing preserves metallurgical characteristics of a material better than welding.

(k) After brazing a component maintains more precision tolerances than welding.

(l) Brazing processes can be automated for bulk production.

(m) Non-metals can be joined to metals.

Disadvantages of Brazing

Following are the disadvantages of brazing:

(a) It requires tightly mating parts.

(b) It requires proper cleaning.

(c) Size of the job is limited.

(d) Joints are not successful at elevated temperatures.

(e) Colour of the filler metal may not match with that of the base metal.

Precautions in Brazing

Following points are to be adhered while brazing:

(a) Properly clean the joints so that it doesn’t contain harmful elements.

(b) Use the right flux in an optimal quantity.

(c) Use proper spelter in a minimum quantity.

(d) The joint must be reasonably tight.

(e) Apply correct heat to work piece and solder.

(f) Avoid prolonged heating.

(g) Use proper atmosphere.

(h) Heat the work pieces to uniform temperature.

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Difference between Brazing and Welding

Brazing Welding
(a) Surfaces to be brazed aren’t raised to fusion point. (a) Surfaces to be welded are raised to fusion point.
(b) Brazed joints aren’t so strong. (b) Welded joints are very strong.
(c) Brazing alloy spreads by capillary action. (c) The weld solidifies almost at the same place where it melts.
(d) Dissimilar metals can be joined. (d) Generally similar metals are joined.
(e) Brazing temperatures are low. (e) Welding temperatures are high.
(f) Components maintain more precision tolerance. (f) Components maintain less precision tolerance.