FAQ

Induction Brazing Basics for jointing copper,silver,brazing,steel and stainless steel,etc.

Induction Brazing uses heat and filler metal to join metals. Once melted, the filler flows between close-fitting base metals (the pieces being joined) by capillary action. The molten filler interacts with a thin layer of the base metal to form a strong, leak-proof joint. Different heat sources can be used for brazing: induction and resistance heaters, ovens, furnaces, torches, etc. There are three common brazing methods: capillary, notch and moulding. Induction brazing is concerned solely with the first of these. Having the correct gap between the base metals is crucial. A too-large gap can minimize the capillary force and lead to weak joints and porosity. Thermal expansion means gaps have to be calculated for metals at brazing, not room, temperatures. Optimum spacing is typically 0.05 mm – 0.1 mm. Before you braze Brazing is hassle-free. But some questions should be investigated — and answered — in order to assure successful, cost-effective joining. For instance: How suitable are the base metals for brazing; what’s the best coil design for specific time and quality demands; should the brazing be manual or automatic?

brazing material
At DAWEI Induction we answer these and other key points before suggesting a brazing solution. Focus on flux Base metals must usually be coated with a solvent known as flux before they are brazed. Flux cleans the base metals, prevents new oxidation, and wets the brazing area prior to brazing. It is crucial to apply sufficient flux; too little and the flux may become
saturated with oxides and lose its ability to protect the base metals. Flux is not always needed. Phosphorous-bearing filler
can be used to braze copper alloys, brass and bronze. Flux-free brazing is also possible with active atmospheres and vacuums, but the brazing must then be performed in a controlled atmosphere chamber. Flux must normally be removed from the part once the metal filler has solidified. Different removal methods are used, the most common being water quenching, pickling and wire brushing.

 

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 Brazing & Soldering Principle

Brazing and soldering are processes of joining similar or dissimilar materials using a compatible a filler material. Filler metals include lead, tin, copper, silver, nickel and their alloys. Only the alloy melts and solidifies during these processes to join the work piece base materials. The filler metal is pulled into the joint by capillary action. Soldering processes are conducted below 840°F (450°C) while brazing applications are conducted at temperatures above 840°F (450°C) up to 2100°F (1150°C).

The success of these processes depends upon the assembly’s design, clearance between the surfaces to be joined, cleanliness, process control and the correct selection of equipment needed to perform a repeatable process.

Cleanliness is ordinarily obtained by introducing a flux which covers and dissolves dirt or oxides displacing them from the braze joint.

Many operations are now conducted in a controlled atmosphere with a blanket of inert gas or combination of inert / active gasses to shield the operation and eliminate the need for a flux. These methods have been proven on a wide variety of material and part configurations replacing or complimenting atmosphere furnace technology with a just in time – single piece flow process.

Brazing Filler Materials

Brazing filler metals can come in a variety of forms, shapes, sizes and alloys depending on their intended use. Ribbon, preformed rings, paste, wire and preformed washers are just a few of the shapes and forms alloys that can be found. The decision to use a particular alloy and/or shape is largely dependent on the parent materials to be joined, placement during processing and the service environment for which the final product is intended.

What is induction heating coil & inductor?

The varying magnetic field required for induction heating is developed in the induction heating coil via the flow of AC (alternating current) in the coil. The coil can be made in many shapes and sizes to custom fit a specific application. The coils can range from tiny coils made of copper tubing used for precise heating of extremely small parts in applications such as soldering and ferrule heating to large coil assemblies of copper tubing used in applications such as strip metal heating and pipe heating.

What is the importance of the induction heating coil (inductor)?
The induction coil design is one of the most important aspects of an induction heating system. The coil is a custom design to give your work piece or part the proper heating pattern, maximize efficiency of the induction heating power supply’s load matching system, and to accomplish these tasks while still permitting ease of loading and unloading your part.

what is induction forging?

Induction forging uses induction to heat metal parts before they are shaped, or ‘deformed’ by presses or hammers.

What are the benefits?

Induction forging has several key advantages over furnace forging. The speed and controllability of induction ensures high throughput. Induction also minimizes oxidation and helps maintain metallurgical integrity. And since induction delivers precise, localized heat, it saves energy. The consistency and repeatability of induction make it ideal for integrating into automated production lines.

Where is it used?

Induction forging is widely used in the metal and foundry industries to heat billets, bars and bar ends. Metals commonly forged with DaWei Induction Heating systems include aluminum, brass, copper, steel and stainless steel.

What equipment is available?

Three families of DaWei Induction heating equipment can be used for forging applications: DW-MF series, KGPS series. However, DW-MF induction forging furnace includes various models that are specially designed for high-output forging of billets, bars, handlebars, bar ends, bolts and pre-formed components.

What Is Induction Melting?

Induction melting is a process where metal is melted into liquid form in an induction furnace’s crucible. The molten metal is then poured from the crucible, usually into a cast.

What are the benefits?

Induction melting is extremely fast, clean and uniform. When correctly performed, induction melting is so clean that it is possible to skip the purification stage necessary with other methods. The uniform heat induced in the metal also contributes to a high-quality end result. DaWei Induction melting furnace have advanced ergonomic features. They not only make workplaces safer, they increase productivity by making the melting process faster and more comfortable. Where is it used? DaWei Induction melting systems are used in foundries, universities, laboratories and research centers. The systems melt everything from ferrous and non-ferrous metals to nuclear material and medical/dental alloys.

What equipment/furnace is available?

DaWei Induction Heating Machine Co offers many different induction furnace ranges to suit a wide variety of melting needs: single-axis tiltpour, dual-axis tilt-pour, moving coil, rollover and laboratory.