Soldering

1
Soldering Braze Welding
Mr. Conrado
2
Soldering Brazing

• Definition
• Liquid Solid Phase Bonding
• The filler metal is melted but the base metal is
  not.
• Soldering
• Temperature below 840 F
• Brazing
• Temperatures above 840 F

3
Brazing vs. Braze Welding

• Brazing
• The weld joint must be fitted so that no filler
  enters the joint.
• Braze Welding
• Uses capillary action to draw filler metal into
  weld joint.

4
Advantages

• Low temperatures
• Can be permanent or temporary
• Dissimilar base metals can be joined.
• Fast speed
• Low chance of parts damage
• Slow rate of heating and cooling
• Parts can easily be re-aligned and be re-melted.

5
Physical Properties

• Tensile Strength
• The ability to withstand being pulled apart.
• Braze joints can have a tensile strength 4-5
  times that of the base metal.
• Shear Strength
• Able to withstand a force parallel to the weld
  joint.
• The greater the joint overlap, the greater the
  shear strength.

6
Physical Properties

• Ductility
• The ability to bend without failing.
• Fatigue Resistance
• The ability to be bent repeatedly without
  exceeding its elastic limit.
• Corrosion Resistance
• A joints ability to resist chemical attack.

7
Flux

• Three major functions
• Remove oxides as result of heating
• Promote wetting
• Aid in capillary action
• As Flux is heated it must flow
• Into joints absorbs oxides and pull in filler
  behind it
• Flux will not remove dirt
• Oil, paint, glue, or rust

8
Filler Metals

• Filler material should be chosen for the specific
  application.
• The criteria for selection should be
• Base metals
• Required joint strength
• Joint design
• Cost / Availability
• Appearance
• Corrosion
• Brazing process

9
Homework

• Video