Induction brazing and soldering is used in a wide variety of industries such as agricultural, aerospace, automotive, medical, electronics, hydraulics, stationary power, fuel cell, lawn and garden, medical and OE.
Induction brazing is a process that incorporates the use of a high
frequency induction power source to create the heat necessary to melt
the braze filler metal and completing an induction brazed joint. Induction
brazing can accommodate joining two or more materials together with the
proper filler metal. The induction brazed process requires the use of a
brazing alloy that has a lower melting point than the base materials being
joined by induction brazing. In induction brazing usually ferrous materials
are heated rapidly from the electromagnetic field that is created by the
alternating current from an induction coil.
Why Chose Induction Brazing:
Induction brazing offers: Selective localized heating
Induction brazing offers: Better braze joint quality
Induction brazing offers: Reduced oxidation over torch brazing and less post braze cleaning
Induction brazing offers: Faster heating cycles
Induction brazing offers: Consistent results
Induction brazing offers: Suitable for large volume production.
HTG Has Specialized Induction Brazing Knowledge
Induction brazing requires specialized knowledge supplied by HTG induction heating specialists. Achieving optimum quality and the best cost advantage requires HTG braze engineers to review the application and all of the details and specifications.
Many customers specify that their components be joined by induction brazing in order to fabricate the brazement.
Prior to HTG quoting induction brazing prices, these steps are taken:
1. Induction brazing considerations include: Braze engineering review of blueprints to verify design, blueprint dimensions, tolerances, joint design and tolerances will meet braze process and quality requirements.
2. Induction brazing considerations include: Filler metal specifications will be reviewed if stated on the blueprint; in the absence of a filler metal call out, HTG braze engineers will determine and recommend a suitable braze filler metal.
3. Induction brazing considerations include: Most induction braze applications involve fixturing to maintain the components to be joined in proper alignment and permit movement of the part in and out of the induction coil. HTG braze engineers will us their experience and follow good engineering principles to determine the correct coil design. All quotations may include engineering, coil and fixture costs.
4. Induction brazing considerations include: HTG braze engineer's looks for the best means to use simplicity rather than complexity in developing the best cost effective methods to be used to fabricate the brazement.
Induction Brazing Process Benefits & Considerations
Induction brazing benefits: Selective heating Induction heating coils can be designed to provide the required heat to very small band width in order to focus the heat only on the area to be brazed. Induction brazing can meet tight blueprint tolerances. Only the area of the part within a close proximity to the braze joint is heated; the rest of the part is not affected.
Induction brazing benefits: Fixturing is generally required to hold the components to be brazed in position during the brazing and cooling cycle. Both fixturing and induction coil design are important with the induction brazing processes. With an engineered coil design, careful fixturing and consistent part placement,
it is possible to simultaneously induction braze multiple joints at one time.
Induction brazing benefits: Better quality induction braze joints
Induction brazing benefits: Induction heating produces clean effective braze joints that are leak proof joints. The process will produce clean and high quality brazed joints. This is one of the reasons that induction brazing is being used extensively for high-precision, high-reliability applications.
Induction brazing benefits: Reduced oxidation and cleaning
Induction brazing benefits: Flame heating in an air atmosphere causes oxidation; scaling and carbon build up on the parts. To clean the parts, the parts require extensive post braze cleaning. Acid pickling baths have traditionally been required. Continuous, batch vacuum furnaces can solve oxidation problems, but have these limitations of their own.
With furnace brazing the whole part must be heated Fixturing parts that do no self align requires higher cost expenditures than induction tooling.
Brazing with induction reduces both oxidation and costly cleaning requirements, especially when a rapid cool-down cycle is used.
Induction brazing fast heating cycles
Induction brazing benefits: Induction heating cycles are short in comparison to flame brazing. The part comes to the required brazing temperature very fast; parts can be processed fast. An efficient induction brazing system will quickly deliver highly localized heating order to create a high quality braze joints. The process does minimize part warpage and distortion. HTG also offers brazing processes using either a controlled vacuum or in an inert protective atmosphere which can significantly improve overall part quality and eliminate costly part cleaning procedures.
Consistent results for induction brazing
Induction brazing is a very repeatable process because variables such as time, temperature, alloy, fixturing, and part positioning are controllable. The induction heating equipment used control cycle time, and temperature control. Both control and monitoring can be accomplished
with pyrometers, visual temperature sensors or thermocouples.
Induction brazing benefits: For processes, which involve medium to high production runs of the same parts, an automated part handling system can be developed and utilized to further improve consistency and maximize productivity. The majority of the jobs induction brazed by HI TecMetal Group is brazed in air.
For the most part, induction brazing and soldering is done in an open-air environment but it can also be done in a controlled atmosphere when necessary to keep the parts completely clean and free of oxidation.
Below we will illustrate our approach to induction brazing in a pure dry hydrogen atmosphere at elevated temperature to 2150°F. Induction brazing generally works best with two pieces of similar metal.
Dissimilar metals can also be joined by induction heating but they
require special attention and techniques. This is due to differences in
the materials' resistively, relative magnetic permeability and
coefficients of thermal expansion.
INDUCTION BRAZE IN A HYDROGEN ATMOSPHERE
Induction brazing Technological Advancement and Benefits:
There are several benefits of performing high temperature nickel brazing process by Induction brazing using localized heating under protective hydrogen atmosphere.
The Induction brazing process blends induction heating using 100% pure dry hydrogen [inert gas. The Induction Brazing is accomplished by placing the components to be brazed in a vessel that allows the transmission of the electromagnetic energy into the assembly.
HTG has made significant advances in the field of controlled atmosphere Induction Brazing enabling us to braze stainless steels, titanium, super alloys and molybdenum in a controlled environment to avoid oxidation and volatilization. Also induction brazing in an inert atmosphere usually eliminates the use of flux in the assembly. The use of flux enhances the wettability of the induction braze filler metal; however, flux entrapment within the braze joint can open the possibility of porosity in the braze joint and flux removal is often difficult.
Induction brazing using a Hydrogen Atmosphere blanket gas to promote wettability and eliminate oxidation.
Induction Brazing Offers these Benefits:
Heat required for melting the filler metal is applied in a narrow band, which can be controlled to within .050.
The metallurgical characteristics of the parent metals will only change in the heat-affected zone. The other areas of the part will remain the same as before the brazing process. Softening [annealing] of the metal will not occur in the non-heated areas of the components.
The induction braze process is much faster than furnace brazing.
Much less energy and process gases are used.
Tooling is generally inexpensive, as long as, the joint designs permits component part self-alignment.
Induction brazing benefits: HTG engineers have made rapid advancement in the technology of Hydrogen Atmosphere Induction brazing. Applications utilizing this process include automotive, aerospace, electronics and medical products. For special applications, several braze joints may be simultaneously brazed.