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Brazing is a technique used to join metal objects using heat. Heating the various metal parts and the additive using a laser beam is a quick method of brazing compared with other brazing methods. Laser brazing results in a high-quality joint that can be painted directly without any additional work required.

Joining metal objects using heat and additives

The joining of metal objects is done by heating up the areas of the objects to be joined and heating an additive in the form of a wire. There are essentially four different types of soldering that have different types of heat sources – flame soldering, induction soldering, shielding gas soldering, and vacuum soldering. Flame soldering is the most common type of soldering.

Soft soldering, brazing, and high-temperature soldering

There are three categories of soldering – soft soldering, brazing, and high-temperature soldering. Soft soldering is the term used when the temperature of the solder does not exceed 450°C. Tin solder and lead solder belong to the soft soldering category. Brazing is the term used when the temperature of the solder is between 450°C and 1000°C, which makes the joint as strong as the base material. Silver and gold are examples of solder used in brazing. High-temperature soldering includes all soldering above 1000°C and makes the solder joints stronger than the base material. This group includes nickel- and copper-based solder.

Flux helps to create a better bond and increases the contact between the solder and the metal

For soldering to work, the additive must not be the same as the metal, as the materials need to have different melting points. For the solder to be as effective as possible, flux has to be used in most cases, either separately or when the solder has a flux channel or coating. Flux comes in solid, liquid, or paste form and is used to improve the solderability of the intended component. Flux works by disagglomerating and preventing the further oxidisation of the base metal during the soldering process. This results in a better bond and contact between the solder and the base metal.

A laser is used as the heat source for brazing

Heating the joint and the additive using a laser beam is a quick and effective method of soldering compared with other soldering methods. This enables non-weldable alloys to be joined and results in a neat joint that can be painted directly without any additional work being required. Laser soldering is a popular method, especially in the automotive industry where it is often used to join roofs and tailgates, for example. Thanks to the smooth surface, the joint can be classed as a visible “class A” surface in the automotive industry.

What does Permanova offer?

Permanova’s robust welding tools have soldering equipment as an accessory. This pendant, which guides the solder wire to the focal point of the laser beam, is available in several designs in order to fit the customer’s product geometry. In a soldering project, it is important to test the parameters that best fit the customer’s product. Initially, the optimal combination of material, wire angle, feed rate, laser power, and any joint tracking requirements is identified. When robot-based laser soldering is identified as the right process for the product, we produce an offer based on the customer’s wishes – regardless of the size of the station, and either standalone or integrated as part of a production flow. We have supplied more than 200 systems worldwide since 1985. A number of these stations are soldering stations, especially within the automotive industry.