| Silvaloy
25 (BAg-27) |
 |
| Nominal Composition: |
|
|
| Silver |
|
25.0
± 1.0% |
| Copper |
|
35.0
± 1.0% |
| Zinc |
|
26.0
± 2.0% |
| Cadmium |
|
13.5 ± 1.0% |
| Total
Other Elements |
|
0.15%
Max. |
| Physical Constants: |
|
|
| Solidus |
|
1125°F
(607°C) |
| Liquidus |
|
1375°F
(745°C) |
| Brazing
Range |
|
1310-1550°F
(710-843°C) |
| Specific
Gravity |
|
8.95 |
| Density
(T.oz./cu.in.) |
|
4.71 |
| Electrical
Conductivity (% IACS) |
|
29.7 |
| Electrical
Resistivity (Michrohm-cm) |
|
5.7 |
| Color |
|
Light
Yellow |
DESCRIPTION:
Silvaloy 25 is historically a modification of Silvaloy 30 with
a further reduction in silver content resulting in a higher melting
point and a longer melting range (250°F). Silvaloy 25 is used
for brazing steel, stainless steel, copper, copper alloys, nickel,
nickel alloys or combinations of these metals. It is similar to
Silvaloy 30 in performance although it contains less silver. Its
broader melting range is helpful where clearances are not uniform.
During melting, Silvaloy 25 passes from the solid state to a mushy
or plastic state and progressively to a liquid. If heated slowly
through this plastic state (1125-1375°F) the liquid portion may
flow from the solid portion. This causes a separation of the alloy
into a low temperature melting (fluid) portion and a high temperature
melting (solid) portion. This phenomenon is called liquation.
The high temperature melting portion will melt only above the
liquidus temperature of Silvaloy 25. For this reason, Silvaloy
25 should be heated rapidly through the melting range.
PROPERTIES
OF BRAZED JOINTS:
Generally, the joint strength using Silvaloy 25 will surpass the
strengths of the base metals. Strength is a function of the base
metals being joined, type of joint, design of joint, joint clearances
and brazing procedures. The recommended maximum operating temperatures
for Silvaloy 25 is up to 400°F in continuous service and up to
600°F in intermittent service. Where improved corrosion resistance
is needed, Silvaloy A-50N and Silvaloy A-40N2 are recommended
over silver base filler metals not containing nickel.
APPLICATIONS:
Typical applications are the joining of ferrous, nonferrous and
dissimilar metals and alloys close joint clearances.
| SPECIFICATIONS: |
|
| AWS
A5.8 |
BAg-27 |
| ASME
|
BAg-27 |
SAFETY INFORMATION:
Silvaloy 25 contains cadmium and therefore upon heating may produce
toxic fumes. It is essential that adequate ventilation be provided
so that personnel will not inhale gases and fumes while brazing.
The operation and maintenance of brazing equipment or facility
should conform to the provisions of American National Standard
(ANSI) Z49.1, “Safety in Welding and Cutting.” For more complete
information refer to the Material Safety Data sheet for Silvaloy
25.
AVAILABLE
FORMS:
Standard forms of Silvaloy 25 are wire, strip, and preforms.
|
