Technologies

Brazing Thin Copper Tube With Induction

Brazing Thin Copper Tube With Induction 

Objective: To braze a thin copper oval tube to a brass fitting at 1400 º F and to cap the other end of the copper tube with a brass plate.

Material: Brass fitting – 0.875 in2 and 2.5 in long (22mm2 x 64mm) Copper tube 0.01 in (0.254mm) wall Brass plate 0.10 in (2.54mm) thick and 0.5 in X 0.25 inch Braze alloy shim and white flux

Temperature: 1400 ºF (760 °C)

Frequency: 300 kHz

Equipment: DW-UHF-10KW induction power supply equipped with a remote heat station using two 1.32μF capacitors (total 0.66 μF) Two custom-designed induction heating coils. Process A split, f our-turn induction coil is used to deliver the heat energy into the brass fitting (Fig. 1). To prevent over heating of the edges of the brass fitting and the thin copper tube, a smaller coil diameter (Fig. 2) was added to deliver heat into the brass fitting. A braze shim preform is placed at the joint area, and is then covered with white flux. The height of the coil is adjusted to deliver proportional heat to the assembly. This setting raises the temperature of the thicker brass piece and the thin copper tube at the same rate enabling a uniform flow of the braze shim preform. The other end of the copper tube is brazed successfully using a 2-turn helical coil (Fig.3.)

Results/Benefits • Preservation of the copper’s mechanical properties • Minimized heat migration along both ends of the tube • Reduced heat-up time (under 60 sec.)

Brazing Copper Assemblies With Induction

Brazing Copper Assemblies With Induction Objective:To heat copper ‘T’ assemblies to 1400(760) ºF(ºC) for brazing Material: Copper ‘T’ assemblies,Silver-copper eutectic braze,White flux Temperature: 1400(760) ºF(ºC) Frequency: 250 kHz Equipment: DW-UHF-20KW, 450 kHz solid state induction power supply with a remote heat station containing two 1.32 mF capacitors (total capacitance 0.66 mF). A custom-designed induction heating coil. Process A … Read more

Brazing Copper Tube to Brass Fitting With Induction

Brazing Copper Tube to Brass Fitting With Induction 

Objective: To use induction heating to braze a copper tube to a brass fitting using a preform braze wire. Processing is to occur under an atmosphere of Nitrogen and 4% Hydrogen gas. The braze preforms melt at 1190°F, but the parts need to be kept below 1300°F. The parts need to be processed at a rate of 175 to 200 per hour which translates into 18 seconds of heating time per part.

Material Copper Tubing Measuring 0.5″ OD and 2″ Long, Brass fitting, Braze Preform, No Flux.

Temperature Above 1190°F but not to exceed 1300°F

Frequency :300 kHz

Equipment: DW-UHF-10KW output solid state induction heating power supply with three (3) busses, eight (8) capacitors totaling 0.66 μF, and a unique four turn helical coil. Process The DW-UHF-10KW output solid state power supply along with a unique four turn helical coil were used to achieve the following results.

Results • The requested atmosphere was provided under a bell jar by supplying 95% Nitrogen/5%Hydrogen at a rate of 25-30 cfh. • A heating cycle of only 10 seconds was necessary to attain sufficient braze flow which surpasses the required limit of 18 seconds.

Brazing Eyeglass Frames With Induction

Brazing Eyeglass Frames With Induction

Objective: Produce repeatable braze joints for the assembly of eyeglass frames. Induction heating is to be used to achieve quality braze joints on the nose bridge, brow bridge and nose piece. Brazing is to be done at 1300°F with approximately 3-5 seconds allowed for heating. Surface quality is of utmost importance since limited post-brazing cleanup is preferred.

Material: Monel Bridge With 18% Silver Braze

Temperature: 1300°F

Frequency: 600 kHz

Equipment:DW-UHF-4.5KW output solid state induction power supply.

Process The DW-UHF-4.5KW output solid state induction power supply was utilized to achieve the following results: • A temperature of 13000F was reached in 3 seconds through the use of a three turn, 0.2″ ID, transverse helical coil. This coil design allows for the pinpoint application of heat to a specific area. • Surface flaws were kept to a minimum due to the use of a gas flood which was comprised of Hydrogen and an inert agent. The Hydrogen acts as a “fluxing” agent which eliminates the need for flux. The inert gas eliminates oxidation of the metal components when at brazing temperature. These two features produce a finished product without the need for post-brazing cleanup. • Present fixturing can be kept due to the use of transverse heating which allows for easy removal of the finished product. Results Overall, induction heating fulfilled all of the objectives established by the customer to produce quality braze joints for the manufacture of eyeglass frames.

Brazing Copper Tube with Induction

Brazing Copper Tube with Induction

Objective: To braze a copper tube ( 3/8″ OD by 2-4″ long) into a 3/8″ fitting in less than 10 seconds. Heating must take place in a channel type coil to allow for easy loading of parts.

Material Copper Tubing and Fitting with Braze and Stay Silv White Flux

Temperature 1300°F

Frequency 215 kHz

Equipment DW-UHF-10kw output solid state induction power supply equipped with a standard heat station containing eight 0.33 μF capacitors for a total of 0.66μF, a step down transformer, and a specifically designed induction heating coil.

Process DW-UHF-10kw solid state induction power supply was setup to achieve the following results: · 2.0 kW of power was directly loaded into the copper tube resulting in a heating time of 7.2 seconds to reach the necessary 13000F for brazing.

Results& Processing ease was achieved through the design of a unique channel type coil comprised of three turns of 1/8″ copper.

Induction Brazing Steel Tube

Induction Brazing Steel Tube

Objective: To heat an oil suction assembly (steel tubing and filter cap) to 1,850°F (1010°C) within 15 seconds for a brazing application.

Material 0.125″ (3.2mm) diameter steel tube and filter cap assembly, high temperature brazing flux, copper ring.

Temperature 1850°F(1010°C)

Frequency 500 kHz

Equipment • DW-UHF-6KW-I induction heating system equipped with a remote workhead containing 0.66 μF capacitors • An induction heating coil designed and developed specifically for this application.

Process A two-turn, specially-contoured helical induction coil is used to heat the tube assembly near the joint area. A copper ring and high temperature flux are then applied to the joint area. Power is applied for 15 seconds until the braze flows.

Results/Benefits Induction heating provides:

• Easy loading and unloading of parts

• Heat very precise areas within production tolerances

• Hands free heating that involves minimal operator skill for manufacturing

Induction Brazing Steel Pipe

Induction Brazing Steel Pipe

Objective: To heat a stainless steel pipe, ferrule and elbow assembly to 1400°F (760°C) within 20 seconds for brazing.

Material 6″(152.4mm)long x 0.5″(12.7mm) diameter stainless steel conduit, 0.5″(12.7mm) long x 0.5″(12.7mm) diameter ferrule, 2″(50.8mm) elbow with 0.5″ (12.7mm) diameter

Temperature 1400°F (760°C)

Frequency 400 kHz

Equipment • DW-UHF-6KW-I induction heating system equipped with a remote workhead • An induction heating coil designed and developed specifically for this application.

Process: A specially designed, three-turn helical coil is used to provide heat to the assembly at the braze joint area. Two small silver solder braze rings are placed at each joint; the joints are coated with black flux to insure that the braze material flows cleanly. The assembly is placed inside the coil and power is applied for 15 seconds to cause the braze to flow.

Results/Benefits: Induction heating provides: • Consistent and repeatable results • No flame process • Faster process time

Annealing Saw Blades with Induction

Induction Annealing Saw Blades

Objective: Induction Annealing saw blades used for cutting bread, prior to hole punching.

Material .38″ (9.6mm) wide and .51″ (12.9mm) wide continuous strips of 400 series stainless steel.

Temperature 600°C (315.6°F) for one second

Frequency 589kHz

Equipment • DW-UHF-6KW induction heating system equipped with a remote workhead containing one 1.00 μF capacitor. • An induction heating coil designed and developed specifically for this application.

Process A three turn helical coil at a 45º angle is used to anneal a 1.2″ (30.5mm) strip of saw blade prior to hole punching.

Results/Benefits Induction heating provides: • Improved quality of blades at hole punching location • Decreased scrap product • Easily incorporated into existing production lines

Induction Annealing Copper Wire

Induction Annealing Copper Wire

Objective: Induction Annealing a brazing copper wire for preform production.

Material: Copper Nickel Silver 2774 Alloy rod 0.070″ (1.8mm) diameter.

Temperature 650ºF(343.3ºC)

Frequency 580 kHz

Equipment: • DW-UHF-6kW-III induction heating system equipped with a remote workhead with one 1.0 μF capacitor, and a 4-20 mA input controller to aid in voltage ramping. • An induction heating coil designed and developed specifically for this application.

Process A unique helical coil consisting of four consecutive coils connected in parallel with a quartz tube lining is used to heat the wire to 650ºF (343.3ºC) for annealing.

Results/Benefits Induction heating provides: • Higher productivity of 27′ (8.2m) per minute • Reduction in surface oxidation & scaling • Consistent, repeatable results

High Frequency Induction Brazing Diamond Inserts

High Frequency Induction Brazing Diamond Inserts

Objective: Induction Brazing diamond inserts to a steel drilling ring

Material : • steel ring and diamond inserts • Braze shim preform • Flux

Temperature :1300 – 1350 (700 – 730) °F (°C)

Frequency :78 kHz

Equipment: DW-HF-15kW, induction heating system, equipped with a remote heat station containing two 0.5 μF capacitors (total 0.25 μF) An induction heating coil designed and developed specifically for this application.

Process: A multi-turn, internal-external helical coil (A) is used to generate the required heating pattern. Initial tests on the ring alone determine system tuning. Flux is applied to the part and the braze shims are inserted into the counter-bored holes (B). This is followed by the synthetic diamonds. The part is loaded into the coil and weight is placed onto the diamonds (C). RF Induction Heating power is applied until the braze flows. The power is turned off and the part air cools to room temperature.

Results/Benefits • reduced ring warping compared to furnace induction heating • decreased cycle time due to reduced ramp-up and cooldown times

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