The document discusses brazing and soldering processes. It states that brazing uses filler metals with melting points above 427°C to join metallic parts, while fluxes are used to remove oxides. Common filler metals include copper alloys and silver. Soldering uses tin-based alloys with melting points below 430°C without melting the base metals. Fluxes are also used to clean the joint area. Applications of brazing and soldering include joining pipes/tubes, manufacturing heat exchangers, and electronics/jewelry work.

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3. • Filler metal melting point is above 427 0 C.
• Filler metal distribution in the joint by Capillary
attraction.
• Metallic parts are Joined by a non-ferrous filler metal.
• The w/p to be joint is not melted here.
The filler metal is only melted and due to the
capillary attraction it adhered to the base metal.
• To obtain good strength surface cleaning is
must one.
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Flux is a chemical
compound applied to the
joint surfaces before
brazing. Its use is essential
in the brazing process (with
a few exceptions noted
later.) The reason? Heating
a metal surface
accelerates the formation
of oxides, the result of
chemical combination
between the hot metal and
oxygen in the air.

6. Brazing
• Steel base metal + Brass filler rod is common
• Lower temp than welding: retains heat treatment (if
present), minimizes grain growth.
• Strong but slow (careful preparation, cleanup)
• Furnace brazing is easily automated
Kalpakjian
en.wikipedia.org
www.kirkframeworks.com
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7. • Tourch‘
• Furnace
• Dip
• Induction
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11. • The added fluxes helps to remove the oxides present in the
filler metal.
• Boric acid, chlorides, fluoxides are some of the fluxes.
• Copper based metals are used as a filler metal.
• For silver brazing silver is used as a filler metal.
• Applications:
• Pipe fittings
• Heat exchangers parts fabrications
• Manufacturing pressure vessels
• Jewellery applications
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12. • Applications
• Low temperature process
• Dismantling of joints is possible
• Quick and clean
• Smooth surface finish can be obtained
• Disadvantages
• Skilled labours need
• Not suitable for mass production
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14. • Filler metal melting point is less than 427 0
C.
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16. Solder = Filler metal
Soldering
Applications:
• Printed Circuit Board (PCB) manufacture
• Pipe joining (copper pipe)
• Jewelry manufacture
Easy to solder: copper, silver, gold
Difficult to solder: aluminum, stainless steels
(can pre-plate difficult to solder metals to aid
process)
• Alloys of Tin (silver, bismuth, lead)
• Melt point typically below 430 degree C.
Flux used to clean joint & prevent oxidation
Zinc chloride, mixtures of zinc chloride and
ammonium chloride.
• Typically non-load bearing
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17. • Soldering Iron & Solder Wire
Manual PCB Soldering
• Heating lead & placing solder
• Trim excess lead
• Heat for 2-3 sec. & place wire
opposite iron
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19. • Cracks
• Cavities
• Solid inclusions
• Imperfect shape or unacceptable contour
• Incomplete fusion
• Miscellaneous defects
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20. Distortion from Welding Processes
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28. • (a) Desired profile for single V-groove weld joint,
• (b) undercut - portion of base metal melted away,
• (c) underfill - depression in weld below adjacent base metal
surface, and
• (d) overlap - weld metal spills beyond joint onto part surface
but no fusion occurs
Weld Profile in Arc Welding
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29. Kalpakjian
Welding Defects
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30. www.mig-welding.co.uk
Welding Flaws:
Incomplete Penetration
(not enough heat input)
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PRAVINKUMAR KAMATCHI