[TheForge] Re: TheForge Digest, Vol 26, Issue 38

[Demon Buddha]

The only critical point to know is that brazing and soldering are the 
same process.  The temperature boundary is an arbitrarily chosen 
delimiter and presents nothing fundamental to differetiate one from the 
other.  The basic properties and principles of soldering and brazing are 
essentially identical.  The only possible fundamental difference between 
them would be the presence of some diffusion bonding between parent and 
filler in the case of "brazing" due to the higher temperatures involved. 
  The degree to which this occurs is a function of time and temperature, 
the more of each resulting in more diffusion, within some limits.  As to 
whether this constitutes a fundamental difference between the two is a 
matter of definitions, I suppose.

Fred Zickrick wrote:
> At 11:37 AM 3/17/2006, you wrote:
> 
>> Folks,
>> A while back there was a discussion about the definitions of soldering 
>> v welding v brazing, to which I added some confusion. Here's something 
>> that just showed up on the metalshapers list.

> So what is braze welding which the AWS discusses in their textbook for 
> welding students??

	As I recall, braze welding is true welding that is carried out using 
copper-based parent and filler metals.  For example, have you ever seen 
brass bar- or handrail of tubular construction that appears to be all 
one large piece (as opposed to those that are obviously screwed together 
from parts)?  If you take a close look at the areas where, say, a 90* EL 
joins to a straight run, you will in fact see the joint area where the 
filler joins the two parents.  The process is basically the same as 
regular welding (I believe this is done using TIG mostly or 
exclusively): the filler melts with the parents and produces an area of 
true fusion, whereas brazing/soldering does not.