Why choose Induction Brazing?

Induction heating technology is steadily displacing open flames and ovens as the preferred heat source in brazing. Seven key reasons explain this growing popularity:

1. Speedier solution
Induction heating transfers more energy per square millimeter than an open flame. Put simply, induction can braze more parts per hour than alternative processes.
2. Quicker throughput
Induction is ideal for in-line integration. Batches of parts no longer have to be taken aside or sent out for brazing. Electronic controls and customized coils let us integrate the brazing process into seamless production processes.
3. Consistent performance
Induction heating is controllable and repeatable. Enter your desired process parameters into the induction equipment, and it will repeat heating cycles with only negligible deviations.

4. Unique controllability

Induction lets operators view the brazing process, something that is difficult with flames. This and precise heating minimize the risk of overheating, which causes weak joints.
5. More productive environment
Open flames create uncomfortable working environments. Operator morale and productivity suffer as a result. Induction is silent. And there is virtually no increase in ambient temperature.
6. Put your space to work
DAWEI Induction brazing equipment has a small footprint. Induction stations slot easily into production cells and existing layouts. And our compact, mobile systems let you work on hard-to-access parts.
7. No-contact process
Induction produces heat within the base metals — and nowhere else. It’s a no-contact process; the base metals never come into contact with flames. This protects the base metals from warping, which in turn increases yield and product quality.

why choose brazing induction

 

 

 
why choose induction brazing

 

What is induction annealing?
This process heats metals that have already undergone significant processing. Induction annealing reduces hardness, improves ductility and relieves internal stresses. Full-body annealing is a process where the complete workpiece is annealed. With seam annealing (more accurately known as seam normalizing), only the heat-affected zone produced by the welding process is treated.
What are the benefits?
Induction annealing and normalizing delivers fast, reliable and localized heat, precise temperature control, and easy in-line integration. Induction treats individual workpieces to exact specifications, with control systems continuously monitoring and recording the entire process.
Where is it used?
Induction annealing and normalizing is widely used in the tube and pipe industry. It also anneals wire, steel strips, knife blades and copper tubing. In fact, induction is ideal for virtually any annealing task.
What equipment is available?
Each DAWEI Induction annealing system is built to satisfy specific requirements. At the heart of each system is
an DAWEI Induction Heating generator that features automatic load matching and a constant power factor at all power levels. Most of our delivered systems also feature custom-built handling and control solutions.

induction annealing tube

What is induction welding?
With induction welding the heat is electromagnetically induced in the workpiece. The speed and accuracy
of induction welding make it ideal for edge welding of tubes and pipes. In this process, pipes pass an induction coil at high speed. As they do so, their edges are heated then squeezed together to form a longitudinal weld seam. Induction welding is particularly suitable for high-volume production. Induction welders can also be fitted with contact heads, turning them into
dual purpose welding systems.
What are the benefits?
Automated induction longitudinal welding is a reliable, high-throughput process. The low power consumption and high efficiency of DAWEI Induction welding systems reduce costs. Their controllability and repeatability minimize scrap. Our systems are also flexible—automatic load matching ensures full output power across a wide range of tube sizes. And their small footprints make them easy to integrate or retrofit into production lines.
Where is it used?
Induction welding is used in the tube and pipe industry for the longitudinal welding of stainless steel (magnetic and non-magnetic), aluminum, low-carbon and highstrength low-alloy (HSLA) steels and many other conductive
materials.
induction welding tubes

What is induction bonding?
Induction bonding uses induction heating to cure bonding adhesives. Induction is the main method for curing adhesives and sealants for car components such as doors, hoods, fenders, rearview mirrors and magnets. Induction also cures the adhesives in composite- to-metal and carbon fiber-to-carbon fiber joints. There are two main types of automotive bonding: spotbonding,
which heats small segments of the materials to be joined; full-ring bonding, which heats complete joints.
What are the benefits?
DAWEI Induction spot bonding systems ensure precise energy inputs for each panel. Small heat affected zones minimize total panel elongation. Clamping is not needed when bonding steel panels, which reduces stresses and distortion. Each panel is electronically monitored to ensure that energy input deviations are within tolerances. With full-ring bonding, a one-sizefits-
all coil reduces the need for spare coils.
Where is it used?
Induction is the preferred bonding method in the automotive industry. Widely used to bond steel and aluminum sheet metal, induction is increasingly employed to bond new lightweight composite and carbon fiber materials. Induction is used to bond curved strands, brake shoes and magnets in the electrotechnical industry.
It is also used for guides, rails, shelves and panels in the white goods sector.
What equipment is available?
DAWEI Induction is the professional induction curing specialist. In fact, we invented induction spot curing.
The equipment we deliver ranges from individual system elements such as power sources and coils, to complete and fully supported turn-key solutions.

induction bonding applications

What is induction tempering?

Induction tempering is a heating process that optimizes mechanical properties such as toughness and ductility
in workpieces that have already been hardened.
What are the benefits?
The main advantage of induction over furnace tempering is speed. Induction can temper workpieces in minutes, sometimes even seconds. Furnaces typically take hours. And as induction tempering is perfect for inline integration, it minimizes the number of components in process. Induction tempering facilitates quality control of individual workpieces. Integrated induction temper stations also save valuable floor space.
Where is it used?
Induction tempering is widely employed in the automotive industry to temper surface-hardened components such as shafts, bars and joints. The process is also used in the tube and pipe industry to temper throughhardened workpieces. Induction tempering is sometimes performed in the hardening station, sometimes in one or several separate temper stations.
What equipment is available?
Complete HardLine systems are ideal for many tempering applications. The chief benefit of such systems is that hardening and tempering are performed by one machine. This delivers significant time and cost savings in a small footprint compared to alternative technologies. With furnaces, for example, one furnace often first hardens the workpieces, with a separate furnace
then being used for tempering. Solid state DAWEI Induction Heating Systems are also used for tempering applications.

induction tempering system

Induction Preheating Hot Rod Heading With IGBT Heating Units

Objective Heat a waspaloy rod to 1500ºF (815.5ºC) for hot heading application
Material Waspaloy rod 0.5” (12.7mm)OD, 1.5” (38.1mm) length, ceramic liner
Temperature 1500 ºF (815.5ºC)
Frequency 75 kHz
Equipment • DW-HF- 20 kW induction heating system, equipped with a remote workhead containing two 1.32μF capacitors for a total of .66μF
• An induction heating coil designed and developed specifically for this application.
Process A seven turn helical coil is used to heat the rod. The rod is placed inside the coil and power is applied for two seconds
providing enough heat to penetrate the inner core. An optical pyrometer is used for close loop temperature control and a
ceramic liner is used so the rod does not touch the coil.
Results/Benefits Induction heating provides:
• Low pressure and minimal residual stress
• Better grain flow and microstructure
• Even distribution of heating
• Improved production rates with minimal defects

Preheating Hot Rod Heading

Induction Brazing Carbide To Stainless Steel Shaft With IGBT Heating Units

Objective Brazing a cone shaped carbide to a stainless steel shaft for a digger
Material Cone shaped carbide 1.12” (28.4mm) dia, 1.5”(38.1mm) tall, stainless steel shaft 1.12” (28.4mm) dia and various length, black brazing flux and braze shims
Temperature 1500 ºF (815 ºC)
Frequency 277 kHz
Equipment • DW-UHF-10 kW induction heating system, equipped with a remote workhead containing two 1.0μF capacitors for a total of 0.5μF
• An induction heating coil designed and developed specifically for this application.
Process A three turn helical coil is used to braze the carbide to the shaft. The steel shaft is fluxed and the braze shim placed on top. The carbide tip is fluxed and placed on top of the shim, lining up the countersunk hole in the carbide. The hole is not fluxed because the flux outgases and causes the carbide to build up pressure and attempt to repel from the shaft. Power is applied for 85 seconds for the braze shim to flow and make a good joint.
DAWEI’s customer has a customer who is unhappy with the braze quality of their digger so our customer is looking for a better quality brazing process. DAWEI’s customer is very happy with the sample brazed diggers and the help he received from the Ameritherm lab in developing his brazing process.
Results/Benefits Induction heating provides:
• Rapid localized heating only where needed
• Creates clean, controllable joints
• Hands-free heating that involves no operator skill for manufacturing
• Even distribution of heating

brazing carbide to shaft

 

 

 

 

 

 

induction brazing carbide to shaft

 

 

 

 

 

 

 

brazing carbide to stainless steel shaft

High Frequency Induction Cap Sealing With IGBT heating units

Objective To heat an aluminum foil inside a plastic shampoo cap for sealing
Material 2.0” diameter, plastic flip top cap, with a 0.9” diameter aluminum foil seal
Temperature 250 – 300 ºF (120 – 150 °C)
Frequency 225 kHz
Equipment DW-UHF-7.5 kW, induction heating system, equipped with a remote heat station containing two 1.5 μF capacitors (total capacitance 0.75 μF).
An induction heating coil designed and developed specifically for this application.
Process A three-turn two-position helical coil is used to heat the aluminum foil in a tunnel style assembly. Product (containers)
passes easily under the induction coil. The assembly is located such that the entire perimeter of the aluminum foil is heated
uniformly. The container and cap is placed under the coil and RF power delivered for 0.12 seconds. The aluminum foil heats
and seals to the plastic of the cap.
Results/Benefits This induction heating configuration fulfills the process
requirements and:
• uses a simple, economical coil design
• increases throughput with a dual-position coil
• delivers quality, consistent seals
• offers a repeatable process, well-suited for automation

induction cap sealing

Induction Heating Aluminum Foil For Cap Sealing with IGBT inductive heater

Objective An induction heater is used to heat a polymer laminated aluminum foil in 0.5 to 2.0 seconds. The heat produced in the aluminum foil melts the polymer that bonds to the neck of a plastic container.
Material Aluminum foil, polyethylene, polypropylene, polyvinylchloride, polystyrene, polyethylene terephthalate, styrene acrylonitrile
Temperature 300 – 400 (ºF), 149 – 204 (ºC)
Frequency 50 to 200 kHz
Equipment DAWEI solid-state induction power supplies operating between 1 & 10 kW at frequencies of 50- 200 kHz. These units operate with remote sealing heads which allows the main power cabinet of the equipment to be located away from the immediate production area. Distances of up to 100 meters are possible. The microprocessor is used to control
and protect the system and ensures that the optimal operating frequency is maintained at all times and that each container
receives the same amount of heat energy from cycle to cycle.
Process Two different types of aluminum foil laminates are available for this application. The first assembly includes backing
board/reseal, a wax layer, aluminum foil, and a heatseal film for supported systems (Figure 1). The second assembly includes a high temperature film, aluminum foil, and a heatseal film for unsupported systems (Figure 2). The procedure is to fit the foil membrane into the cap and to fit the cap to the container after the product is filled.
Results For the aluminum foil assembly as shown in Figure 1, heat induced in the metallic foil by the induction coil almost
instantaneously melts the polymer coating and the neck of the container forming a hermetic seal between the heat seal film
and the rim of the container. The heat also melts the wax between the aluminum foil and the back board. The wax is
absorbed into the back board. This results in an air tight bond between the aluminum foil/membrane and the rim of the
container, the back board is released and remains in the cap.

Process (cont’d) In the case of unsupported membranes in Figure 2, one side of the aluminum foil is coated with a heat sealable polymer film and this face that will be in contact with and sealed to the container. The other side of the foil that will be in contact with the cap has a higher melting-point film that prevents adhesion of the aluminum to the cap allowing the end user to unscrew the cap. Unsupported membranes are typically used where the end user pierces the tamper evident membrane prior to dispensing the product. The aluminum foil acts as a vapor barrier preserving the freshness of the product and prevents it from drying.

induction heating aluminum foil cap sealing

Shrink Fit Steel Gear onto Shaft With High Frequency Induction Heating Units

Objective Heat the bore of a hardened spur steel gear to shrink fit onto a gear motor shaft. This is part of a chair for the disabled.
Material Steel gear 2.5” (63.5mm) OD, .75” (19mm) ID x .625” (16mm) thick, temperature indicating paint
Temperature 400 ºF (204 ºC)
Frequency 300 kHz
Equipment • DW-UHF-3.2 kW induction heating system, equipped with a remote workhead containing two 0.66 μF capacitors for a total of 1.32 μF
• An induction heating coil designed and developed specifically for this application.
Process A four turn helical internal coil is used to heat the gear bore.
The coil is inserted into the gear bore and power is applied for 90 seconds to reach the required 400 ºF (204 ºC) and expand
the gear bore. The gear is then placed on the shaft and allowed to cool, creating the shrink fit between the gear and
the shaft.
Results/Benefits Induction heating provides:
• No pre-heat cycle, heat is available on demand
• Energy efficient, heats only the part, not the atmosphere around it
• Controlled, even distribution of heating
• Faster production times

Shrink Fit Steel Gear onto Shaft

Induction Shrink Fitting Carbide Ring With IGBT Induction Heating Units

Objective Shrink fitting a carbide ring into a steel valve seat
Material Steel valve seat 6” (152.4mm) OD with 3” (76.2mm) ID hole & .75” (19mm) thick, carbide ring
Temperature 500 ºF ( 260 ºC)
Frequency 85 kHz
Equipment •DW-HF-15kW induction heating system, equipped with a remote workhead containing two 0.50 μF capacitors for a total of 0.25 μF
• An induction heating coil designed and developed specifically for this application.
Process A three turn helical coil is used to heat the steel valve seat.
The steel valve seat is placed in the coil and heated for 50 seconds to enlarge the center hole & drop the carbide ring in
for the shrink fitting process.
Results/Benefits Induction heating provides:
• Accurate and repeatable results
• Ease of integration into existing production lines
• Energy efficient, only heats the part, not the atmosphere around it
• Hands-free heating that involves no operator skill for manufacturing
• Even distribution of heating

shrink fitting carbide ring

 

Induction Shrink Fit Aluminum Shaft with IGBT induction heating systems

Objective Heat aluminum impeller blades to 200 ºF (93 ºC) and shrink fit onto a shaft.
Material Aluminum impeller blades with a .28” (7.109mm) bore, aluminum shaft
Temperature 200 ºF (93 ºC)
Frequency 255 kHz
Equipment • DW-UHF-6W induction heating system, equipped with a remote workhead containing one 1.0μF capacitor.
• An induction heating coil designed and developed specifically for this application.
Process A split two turn helical coil is used to evenly heat the opening on the impeller blade. The impeller blade is heated for 20 seconds to reach the 200 ºF (93 ºC). The impeller blades are then removed from the coil & slipped over the shaft to complete the shrink fitting application.
Results/Benefits Induction heating provides:
• Repeatable results
• Reduced cycle time, lower consumables cost
• Even distribution of heating

Shrink Fit Aluminum

 

 

 

 

 

 

 

 
Shrink Fit Aluminum with induction