Welding is used across many industries that are constantly evolving, creating new demands for joining different materials. The welding industry couldn’t stay still with constant changes and the addition of new materials, and simply had to evolve alongside the advancements made in materials that various industries are using today.

While mainstream arc welding processes can handle around 90% of situations that welders encounter today, there are niche situations where advancements are needed or a modern approach to weld the materials together. 

Improved productivity, efficiency, and, not to mention, quality, is a challenge that the welding industry has always been dealing with. But with the introduction of materials with a unique chemical composition, things become even harder to cope with. The solution for traditional welding methods like TIG welding or MIG welding is to evolve, or to introduce new ways of dealing with modern types of situations.

Today, we want to mention a few advanced welding techniques that represent modern alternatives to traditional welding techniques. 

Electromagnetic Pulse Welding and Crimping

Electromagnetic pulse welding is an innovative process that involves the use of electromagnetic forces for joining materials. The greatest advantage of using this process is that it can join dissimilar materials together, which are difficult to join with conventional welding techniques, like MIG welding, for instance.

The base principle of this type of welding is that it uses electromagnetic forces to deform and weld the two workpieces together. The workpieces are placed inside a coil where a large amount of energy is compressed and discharged in a short period of time, with some systems being able to discharge at peak currents that can range from tens of kA to the MA range, and pulses are typically tens of microseconds.

The high energy flowing from the coil and the discharge of electric energy create eddy currents in the external workpiece. The currents in the coil and the workpiece induce magnetic fields that oppose each other. The resulting opposing magnetic fields force the external parts towards the internal parts at high velocity, enabling welding. It results in permanent distortion, without any spring-back of the workpiece. Impact velocities are typically in the low hundreds of m/s, in some specialized setups, the velocities may approach 1000 m/s.

The main upside of electromagnetic pulse welding is that it is a cold process, meaning that the technology does not use heat but pressure to join the two materials together. The workpiece does not get hotter than 30 °C at the outer surfaces the most. It offers a high production rate with high repeatability and constant join quality. Also, no shielding gas, fillers, or other auxiliary materials are required.

However, lap joints are needed, as one material has to impact the other for the process to work. Also, one sheet of metal has to be a good conductor, while the other workpiece has to withstand the impact of the first to prevent deformation. 

Friction Stir Welding

Friction stir welding is a solid-state process that uses a non-consumable tool to join the two materials together. It connects the two workpieces without actually melting the workpiece material, while heat is generated by friction between the rotating tool and the workpiece material.

FSW is an attractive welding process because it creates minimal distortion and residual stress while at the same time making higher integrity welds. Compared to conventional welding techniques, it does not require any filler material, gas, or other consumables. More so, while it requires much less energy, it also does not create any harmful gases, spatter, or slag. It is also much quieter, improving the working environment and boosting productivity at the same time.

The biggest upside of FSW is that it can help weld some dissimilar materials together, like aluminum-magnesium and aluminum to steel. It does not require any post-weld treatment and has low distortion and shrinkage.

Ultrasonic Welding

Ultrasonic welding is a process that uses high-frequency vibration energy. This is a solid-state welding technique, meaning that the welded materials are not melted together, but actually brought into a plastic state in order to be joined.

The workpieces are held together by a low static force, where the tip of the sonotrode is held in direct contact with the welded piece, while the other piece is attached to an anvil to prevent it from moving. The system will send small, linear, cyclic movements to the tip of the sonotrode and these vibrations ensure that the sonotrode vibrates into the workpiece, transferring the ultrasound energy to the welding interface.

The result is that the sonotrode and the welding piece start vibrating at the same phase and amplitude. Vibrations create friction heat between the welded materials, making them plastic and allowing them to bond. Ultrasonic welding can be used for a wide range of metals and plastics, including various coated materials and dissimilar metals.

Unfortunately, its use is limited to soft metals only, or you can only weld thin to thick materials. Also, you are going to want to use hearing protection with this one. The produced frequencies go beyond human-perceived frequencies, except that certain subharmonic vibrations can occur that cause a nuisance sound, resulting in potential hearing damage. 

Electron Beam Welding

Electron beam welding is a fusion process where heat is generated due to the impact of electrons, with them accelerated by the electron gun. With this process, you can weld a complete spectrum of metals and various material combinations.

The welding energy comes from the workpiece, where a bundle of electrons is gathered and then accelerated, released, and then focused on the workpiece. If there is enough energy, it will melt locally and partly evaporate. Because the beam of electrons scatters in gas, the process has to be performed in a vacuum. This prevents oxidation from occurring while welding, as there is no interaction between oxygen and hydrogen. It makes electron beam welding ideal for welding materials that oxidize very quickly, such as molybdenum, tungsten, zirconium, or titanium.

Electron beam welding is mainly used in the aircraft or the space industry, but has also found its use in the automotive sector. It creates minimal distortion, which is perfect for the series production of gears of the gearbox. Also, due to low heat output and high precision, this type of welding is useful when welding electronic components together.

Besides low energy consumption, it offers high reproducibility and excellent weld quality. It is good for weld depth of more than 100 mm, and you can also weld thin seams with a narrow HAZ.