Furnace Brazing Filler Metals

furnace brazing

Of all brazing processes, the most variables are presented when brazing in atmosphere or vacuum. Among these are the type of base and filler metal used, type of atmosphere, dew point, temperature, and even furnace construction. Most furnace brazing pastes are supplied without flux, consisting only of atomized filler metal and a neutral binder.

Fusion offers a full line of controlled atmosphere brazing pastes for various base metals and filler metals. The filler metals include copper and nickel based alloys.

Select a Fusion Furnace Paste:

EXO

  • Typically first choice for copper brazing in exo/endo atmospheres
  • Minimal to no residue under broad range of part cleanliness and atmosphere conditions
  • Not recommended for H2:N2 atmospheres
  • No hot or cold slump
  • Non-spattering
  • Compatible with wide range of metal concentrations
  • Easily dispensed through “squeeze bottles”
  • Adheres to part after drying
  • Good water washable cleaning properties

CCR

  • Leaves minimal residue
  • No hot or cold slump; non-spattering
  • Suitable for exo/endo atmospheres, H2:N2 atmospheres
  • Compatible with wide range of metal concentrations
  • Easily dispensed through “squeeze bottles”
  • Adheres to part after drying

CDW

  • Similar to CBL with improved/reduced stringiness and less hot/cold slump
  • Cleaning properties with water better than CBL, but not as water washable as EXO and CCL
  • Adheres to part after drying
  • Ideal for extremely low dew point hydrogen atmosphere

CNN, CNG, CKG

  • Suitable for either atmosphere or vacuum brazing
  • Low ash value
  • Leaves minimal to no residue where low dew points (minimum 20° or below) and high temperatures (1800° or above) are maintained.

CBL, CBC, CFW

  • Non-drying, neutral binders for atmosphere brazing
  • Restrictive flow and slump properties permit use on most vertical joints
  • Flow properties may be modified with additives depending on the application

PNP

  • Recommended where dew points are marginal and furnace temperatures are in the lower (silver brazing) range
  • Not recommended for use on vertical joints due to pronounced slump in both hot and cold stages

CAP

  • Suitable for use in H2:N2 and dissociated ammonia atmospheres with with low dew points (0 to -30°F)
  • Leaves no residue under these conditions
  • Also suitable for use in vacuum furnaces

Furnace Paste Selection Guide

Type of Atmosphere Filler Metal Base Metals Joined Recommended Binders
Exothermic and Endothermic Atmospheres Copper
(AWS BCu – 1a)Fusion 1900
Carbon Steels EXO CCR CNG
CBL CDW
Bronzes*
(Various Cu-Sn Ratios)
Carbon Steels EXO
Hydrogen – Nitrogen
Mixtures including
Dissociated Ammonia
and Pure Hydrogen
Copper
(AWS BCu – 1a)Fusion 1900
Stainless Steels CNG CDW CCR
CBL CAP
Bronzes*
(Various Cu-Sn Ratios)
Stainless Steels CDW