Forging Silver Bars to Create Collectible Coins

A client contacted THE LAB at Ambrell because they needed to heat silver bars to 1200 ºF (649 ºC) for a forging application. The end product was a collectible coin. THE LAB at Ambrell determined that an EKOHEAT^Ⓡ 125 kW, 2-6 kHz induction heating power supply with a workhead and twenty-turn helical coil specifically designed for this forging application would meet this application's requirements.

Initial testing was conducted to optimize the power delivered to the part. The coil inside diameter (ID) had to be very close to the outside diameter (OD) of the bar due to the high conductivity of Silver. For this reason, conventional water-cooled steel tubes may not work to support the bars as they rest in the induction coil. Consequently, a stainless-steel shim was used to support the silver bar in the coil. With the EKOHEAT 125 kW/3 kHz power supply, the silver bar heated to temperature within 60 seconds.

Induction offered several advantages to the client. The client had been using an oven, but induction offered a faster rate of heating and additional throughput. It also offered instant on/off heating, which is a significant advantage over oven heating. Finally, induction requires less of a footprint than an oven, especially when you consider that the workhead can be placed away from the power supply. 

If you have an application that might benefit from induction heating, be sure to take advantage of complimentary application testing from THE LAB. You can observe testing remotely, in-person or simply request a lab report, video and your parts for inspection. Contact us today to get started.