Monday, March 10, 2014

ChannelFlux Silver is here!

In response to the overwhelming feedback we've gotten from our customers after experiencing the benefits of ChannelFlux for aluminum brazing, we are now offering ChannelFlux Silver!

ChannelFlux Silver brings all of the benefits of a flux integrated brazing alloy to your silver brazing application:  an open channel design offering superior wetting to flux cored alloys, a flux system that releases entirely in advance of the alloy, delivery of the perfect amount of flux with every braze, and less opportunity for contamination.

ChannelFlux Silver is available in a variety of wire sizes, silver brazing alloys, and wire preform shapes.  Contact us to find out how ChannelFlux Silver can benefit your brazing applications!

 


Wednesday, October 16, 2013

Preforms Align with Lean Manufacturing Goals


A preform, a manufactured shape of brazing filler metal, may be pre-placed in an assembly prior to automated brazing. Made from bulk wire or strip, preforms include rings, washers, discs, shims, edgewounds, and custom shapes.
A key benefit of preform use is speed and accuracy. Conducive to repeatable, controlled processes associated with automated production, brazing preform rings are typically used in HVACR manufacturing where they are loaded on to copper return bends.
Preforms ensure the placement of the correct amount of brazing alloy in the correct position on the assembly, eliminating excessive use and flow of filler metal, making them well suited to help achieve lean manufacturing goals like maximum quality, productivity, and profitability.
Bellman-Melcor makes thousands of custom preforms in a variety of brazing and soldering alloys, specifically designed to fit the tolerances of brazed components in your automated processes. Click here for a quote!

Monday, September 23, 2013


Custom Preforms Provide Maximum Performance and Minimum Waste

A preform, a manufactured shape of brazing filler metal, may be pre-placed in an assembly prior to automated brazing.  
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Made from bulk wire or strip, preforms include rings, washers, discs, shims, edgewounds, and custom shapes.
A key benefit of preform use is speed and accuracy.  Conducive to repeatable, controlled processes associated with automated production, brazing preform rings are typically used in HVACR manufacturing where they are loaded on to copper return bends. 
Preforms ensure the placement of the correct amount of brazing alloy in the correct position on the assembly, eliminating excessive use and flow of filler metal, making them well suited to help achieve lean manufacturing goals like maximum quality, productivity, and profitability.
Bellman-Melcor makes thousands of custom preforms in a variety of brazing and soldering alloys, specifically designed to fit the tolerances of brazed components in your automated processes.  Click here for a quote!

Monday, August 5, 2013

Brazing Carbide

Silver brazing shims have proved the best way to secure carbide to tools.  Shims require no additional space and can be replaced or salvaged by melting off and re-brazing.
Torch and induction brazing are the most adaptable processes for joining carbide tips:  torch brazing for occasional work or in cases of varying size, and induction brazing for a production environment.  While furnace brazing is possible, it is not recommended due to problems positioning and holding the carbide during heating.  However, a furnace and assembly fixturing may be economical in the case of large production requirements.
As tungsten carbide is difficult to wet, a brazing alloy containing nickel should be used. BrazeIt A50N is the most commonly used alloy when brazing carbide, whether it be in solid or plymetal form.  For applications where carbide and heat treatment of steel is done in one operation, BrazeIt A40N2 is the recommended alloy.  Coupled with black flux, run out of alloy is better controlled at longer and higher brazing temperatures.
Tungsten carbide has a thermal expansion rate of 1/2 that of steel. During cooling, the contraction of carbide will be 1/2 the contraction of the steel shank.  The brazement, being proportional to the size of the carbide, is placed under internal shear stress, which when combined with service stress during use, can lead to joint failure on large inserts and cracking or breaking on thin carbide blanks.  To prevent failure, use plymetal on carbide exceeding 3/8 or 3/4 in max. dimension.

Wednesday, July 3, 2013

ZA-1: Addressing a Narrow Thermal Processing Window

Addressing the narrow thermal processing window is perhaps the biggest concern when considering an aluminum brazing project.  The problem, simply stated, is that the aluminum base metals melt at about the same temperature as the brazing filler metal.  The solidus temperature, the last temperature at which the alloy is completely solid, marks the point where damage begins to occur in the base metals.  The most standard BAlSi aluminum brazing alloy, 4047, has a melting range of 1070° - 1080°.  By comparison, 6061 and 6063 grades of aluminum have a solidus of 1100 and 1140 degrees respectively.  1100 and 3003 grades of aluminum have a higher solidus, 1190 degrees, but still presents a significant brazing challenge.
The availability of cesium fluxes and their low melting range (788°-842°) have ignited interest in Zn-Al brazing alloys.  Bellman-Melcor's
ChannelFlux® ZA-1 (78Zn 22Al) is specifically designed for use on thermal transfer devices.  The low melting phase of this alloy (826°-905°) is perfectly matched to the thermal activity of the Cs fluxes, providing a substantial thermal window for most aluminum brazing applications, especially for 6xxx aluminum.  Tensile strength and burst tests with 78Zn 22Al consistently show the braze joints demonstrate greater durability than the base metals, and saltwater spray testing to ASTM B117 for 2000h showed no signs of visible corrosion and no deterioration of mass.
Call us for a quote or to test ChannelFlux ZA1 in your application!

Tuesday, May 21, 2013

Thursday, April 4, 2013

Brazing, Soldering, Welding, its all the same....(right?)



WRONG!
At least once a week a customer calls us to order an existing item and says, “I need to order more of that silver solder.”  Sometimes, the customer asks for “hard solder”.  However, research into the part number reveals that the customer is really referring to a brazing alloy.
The devil is in the details – what makes the difference between whether you are ordering a “brazing alloy” or “solder wire” is not just a matter of metallurgical composition.   A brazing alloy is a filler metal reaching a liquid state (“liquidus”) at a temperature above 840⁰.  When the filler metal reaches the required temperature, capillary action works to allow the alloy to wet the base metals and form a brazed joint.  Soldering refers to similar actions forming a metal joint, but at temperatures below 840⁰.  Welding, however, differs considerably; while brazing and soldering melt the filler metal alloy, subsequently forming a joint by capillary action, welding forms a joint by melting the base metals as well as the filler metal; temperatures are not the defining factor.

Seems simple enough, right?

To remember the difference between a brazing alloy and a soldering alloy, it may help to make note of the alloy name.  Soldering alloys are frequently and commonly referred to by the composition percentage of the chemicals they are made from, i.e. 98/2, 95/5 Tin-Silver, and 50/50 Tin-Lead.  It’s not always that easy; some alloys traditionally considered for welding, like BrazeIt 681, can also be used in brazing applications.
If you have questions about what alloy is right for your process, give us a call!  You can also visit our website to view our catalog of brazing and soldering alloys, complete with technical information and MSDS'.