Fusion welding. The
joining of two or more metals by melting
(fusing) them together, eg, welding steel with
an alloy such as Magna 31.
Brazing. The joining
of two or more metals with a welding alloy
that has a lower melting than any of the base
metals, but has, itself, a melting point over
537 oC.
Soldering. The
joining of two or more metals using a welding
alloy with a melting point below 537 oC.
Soldering is probably the
most widely used of all methods of joining
metals. However, soldering is also probably
the least understood of all metal joining
methods.
Soldering is used for two
main types of application: production joining
and maintenance joining. In production,
soldering such items as automobile radiators,
electronic and electrical equipment, are
usually the result of a mass soldering
installation machine which is complicated and
programmed by a specialist consulting
engineer.
Once the initial adjustments
have been made, the operation becomes a simple
metronome assembly without the need for human
assistance. All or most of the variables are
controlled. Production soldering is an
automated system based on ideal conditions,
clean metals, preplanned joint design and no
human error factors.
Industrial maintenance
soldering is entirely different from
production. Soldering can play an important
part in industrial maintenance such as
electrical circuits, plumbing, tubing,
vehicles, sheet metal, wiring and a myriad of
applications.
There are many different
applications where Magna Maintenance
Soldering is the ONLY answer and the RIGHT
answer. For example, in a milk factory. There
are times when dismantling or enjoining parts
is essential to the efficiency of the
operation. The stainless steel piping can be
joined with Magna
88C. The result is a sanitary,
leak-proof strong joint. However, the time
comes when the cleaning operation must be done
and, the only way to do this is to take the
piping apart and - clean it. This can be
easily achieved by a minimal amount of heat to
dismantle the piping. The piping is cleaned
and then once again joined back together with
Magna 88C.
This could not be done,
either by brazing or welding. Nor could the
machine be transported back to the
manufacturers for dismantling and repair. This, however, is only an isolated example of
the thousands of situation-saving applications
for the Magna Maintenance Soldering
Process.
The repair of the aluminum
guttering on a roof is a classic example. Ordinary production solders just cannot cope
with a situation like this. Gas or arc welding
would distort the metal.
Magna 51 can join the
aluminum gutter, giving it strength and
rigidity and making it leak proof.
Another example is auto body
repairs where Magna 81 fills in
dents. It is far superior to ordinary solders
or plastic fillers because it is vibration
proof, peel proof and easily applied at very
low heat.
Still another example is
soldering cast iron, (once thought to be
impossible) which is easily accomplished with
Magna 79. It can join a cast
iron intake nipple to a copper radiator or
seal cracks in cast iron housings at such a
low temperature that dismantling is not
necessary.
There are endless numbers of
applications where Magna Maintenance
Solders salvage equipment that might otherwise
have had to be scrapped. Instrumentation
components, galvanized sheet metal, plumbing
connections, water piping, sheet metal machine
guards, electrical apparatus and numerous
other applications that occur in every
factory, farm, mine or industry can benefit
from the use of Magna Maintenance
Soldering Alloys.
Magna Solders are
better for maintenance applications than
ordinary solders for the following reasons:
(1) The Magna vacuum-melted
method of solder production
Magna Solder Alloys
are made by an exclusive proprietary vacuum-
melting process. Ordinary solders are not
manufactured with vacuum melting but are
melted in the open air. The Magna
vacuum melting process provides the following
major advantages:
- Vacuum melting eliminates
dross, gas, tin oxides, lead oxides and
other contaminants.
- This unique manufacturing
method gives the Solder Alloys fewer centres
of nucleation than ordinary solders. Because
of this, when the molten Magna
solders cool, the grain structure is finer
and there is less danger of segregation of
the component metals.
- Magna Solders
provide shallower fillets with better
contours; they exhibit vastly superior
holding power.
- Magna Solder
Alloys are so superior to ordinary solders
that solder joint failures are almost
unknown.
(2) Magna solders contain
higher-purity metals
Ordinary solders are made
from low-cost scrap tin and lead. The fact
that the results from these solders are
limited seems to have little or no distraction
to its sale for the simple reason that few
industries realize just what goes into a
solder.
The impurities in ordinary
solders cause serious and repetitive problems
in nearly every field of soldering. The
impurities include such metals as copper
(which lowers the over-all resistivity); zinc
(which will not go into solution but remains
crystalline and gritty); bismuth (which has
the ability to change the microstructure);
aluminum (another that will not go into
solution) and finally cadmium (which lowers
the spread-rate).
Magna uses only
virgin metals rated at 99.99% purity. These
are melted in a vacuum and homogenized
ultrasonically. Resistivity tests are then
made on a double-Kelvin bridge using the
four-pronged method.
Magna Solders are
made from exceptionally high grade tin ore,
which is crushed and concentrated by the
floatation process. Impurities such as arsenic
and sulphur are completely removed by an
oxidizing roast and a dilute acid bleach. Other impurities such as lead, bismuth and
antimony are removed by choloridizing roast
and acid bleaches.
The ore is then purified
once again in a reverberatory furnace which
has been charged with concentrated tinstone,
and mixed with metallurgical grade coal. The
tin at this stage is approximately 99.50%
pure.
However, in the Magna
process, the purity factor does not stop
there. The tin is refined by four additional
processes to bring it to the highest level of
purity available in any commercial solder
today.
Sub formulations: The
perfect solders are those that can be applied
at the lowest temperatures. However, soldering
temperature is the combination of 2 factors: Time and degree of heat. For example, a solder
that requires 190 oC and remains
molten or liquid for 3 minutes, requires
substantially more heat energy than a solder
that requires 210 oC to melt but
which solidifies in five seconds. Molten
solder reacts with metals such as copper - and
formed on the copper surface, is a chemically
distinct, intermetallic compound phase. And,
most important, as long as the solder remains
MOLTEN, the reaction forming this intermetallic compound continues. This
compound (chemically CN6 SN6) is extremely
hard and brittle. It is quite easily broken in
shock by tearing forces.
Thick intermetallic alloys
are weaker than thin layers. The obvious
answer then is to reduce the soldering time.
The less time the solder is molten and the
faster it solidifies, the stronger and less
brittle the bond.