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 custom double-wound pancake-helical coil combination is used to efficiently transfer RF Induction Heating power. Tests were conducted using temperature indicating paint to establish heating profiles and time-to-temperature. After the optimum time-totemperature of 3-5 minutes is established, a braze ring is placed at the joint and white flux applied to the joint area. The first joint on each piece takes 5 minutes with subsequent joints on the same copper piece taking much less time (~3 minutes).

Results/Benefits · Semi-automatic process reduces amount of operator laborinvolved· Easy and effective completion of braze joints