While many companies, fabricators, and even machining services may offer brazing as one of their services, it is actually a very specialized process that requires expertise, experience, and a good understanding of the technique and the metals in use. Brazing metals is a traditional way of creating solid, leak-proof joints that are much stronger than soldering or welding, and with today’s technology it is even better than ever.
To help understand why it is essential to choose experienced companies over companies offering just low prices for brazing metals, taking a closer look at the process, and the technology in use today is very helpful.
The Filler Metal
When brazing metals, the temperature is important and so is the choice of a filler metal. To be considered brazing the filler metal has to melt at a temperature greater than 840°F but also less than the melting temperature of the metal or metals that are being joined.
It is possible, through brazing, to join two very different metals such as a copper and stainless steel. However, the choice of the filler metal will be critical to not only have a liquidus (melting temperature) that is below either of the metals but also one that will bond with the metals at the joint.
Most common filler metals include copper, gold, aluminum, nickel, cobalt, or silver in a variety of different alloys.
While brazing metals is one of the lowest cost options in producing top quality joints for any type of part or component, it is important to choose a company to complete the process that has experience with brazing.
Not only will this ensure that the project is completed to standards, but it will also greatly reduce any waste. Typically companies without experience tend to have higher waste on a project, resulting in an overall higher cost to you.
When brazing metals, the filler metal is the only metal that reaches the melting point. This means there is no structural change in the metals on either side of the braze, and their properties do not change.
Instead, the liquid filler metal is drawn into the heated joint area through capillary action, sealing wide to narrow gaps in the joining process in a way that is much more difficult using welding techniques. The result of brazing metals is a durable, tough joint that is stronger than the metals, corrosion resistant and offers virtually unlimited possibilities for joint configurations.