The new Coherent HIGHtactile laser welding head simplifies and improves the wire welding process for increasingly demanding production tasks in the electric vehicle industry.
The new Coherent HIGHtactile process head is the latest development of our successful tactile laser welding heads; the tactile head mechanically senses the position of the weld joint as it moves over the part. During tack welding and brazing, the Coherent HIGHtactile head applies pressure to the wire along the joint between the parts. By measuring the forces applied, the head detects changes in the position of the joint as it moves along the weld.
In welding that does not involve an additional wire, a mechanical "finger" rides in the weld joint and performs the same function. As a result, the HIGHtactile welding head consistently produces perfect wire or wire-free welds on curved or intricately shaped parts - such as automotive roof joints, tailgate and trunk lid joints.
Wire welding
Wire welding is a highly adaptive process for automotive manufacturers as they increasingly use a variety of sophisticated metal alloys to increase the strength of vehicle components while reducing their weight. Unfortunately, some of these alloys - particularly aluminum and steel - can be challenging to weld.
For example, melting can "cook out" some of the more volatile (lower melting point) elements that give the alloy its desirable properties. The resulting alloy in the weld joint then does not have the same properties as the rest of the material. This is particularly a problem for automotive applications when a weld joint is produced that has lower mechanical strength than the rest of the part.
In some of the most commonly used aluminium alloys, hot cracking can often occur during welding. Hot cracking occurs when large cracks or micro cracks form in the weld joint as the part cools. Needless to say, these problems reduce the strength of the weld joint.
Wire welding also solves the problem of part face tolerances in automotive manufacturing. This means that mechanical gaps between the parts being joined create unwanted gaps in the weld joint. This is especially true for stamped parts, which can have relatively large dimensional variations between parts, leading to poor fits. Pressed parts are now widely used for the construction of "battery boxes" for electric vehicles.
Soldering
Brazing is a fairly similar process to wire welding and has been used in the automotive industry for decades to create cosmetically attractive joints. It is widely used for joints that are visible to the consumer, such as around the trunk lid. In the case of a trunk lid, the wire is melted into the joint, but the base metal itself remains unmelted. The new wire material is sandwiched between the sheets to create a cosmetically pleasing joint. A perfect solder joint is smooth enough that no further preparation is required before painting.
HIGHtactile makes wire welding easier
The Coherent HIGHtactile welding head is the result of Coherent's 20 years of experience designing seam tracking systems for welding and soldering at Coherent. It offers increased productivity and superior results in EV, body-in-white and other assembly applications. Coherent welding heads are compatible with a variety of fiber lasers with up to 8 kW of output power - and bringing the new Coherent HIGHtactile welding head into production is easier than ever. In addition to a sophisticated set of built-in sensors to maintain position, the HIGHtactile head also includes a high-quality optical system that is designed to faithfully maintain the original laser beam profile all the way to the work surface. For example, a laser with a flat beam profile can be used to optimize steel welding, while a different profile can be used to achieve ideal results in soldering.
Learn more about HIGHtactile.