Ceramic ferrules are vital in the drawn arc stud welding process, and this blog can help you to understand it.
Ferrules are protective rings used to protect the stud during welding, and in a variety of applications, from fiber optics to stud welding. As a result, the materials involved in the welding process are less likely to be contaminated.
Small rings derived from ceramic material are called ceramic ferrules (also known as ceramic arc shields), which allows an effective drawn arc stud welding process to work. Without these, the procedure will be ineffective, and the welds will be weak. So, understanding how drawn arc stud welding works is critical.
First, the drawn arc machine is calibrated for the appropriate stud diameter. The stud is then positioned on the plate and prepared to be welded. When the process starts, the stud is slightly lifted from the plate and a pilot-arc follows.
Subsequently, the main arc that melts the stud tip into molten metal develops a metal pool on the plate. Next, the machine return-springs the stud to the plate, fusing it with the molten metal to make the extremely strong weld.
Ferrules are needed to contain the molten metal pool, preventing it from spreading ouward and leaving insufficient metal to fuse the stud to the plate and resulting in a sloppy finish.
The ceramic primarily protects the stud from the air, preventing porosity and contaminants during the welding process, and reduces UV exposure in the surrounding area. They form a ring around the stud, containing the molten pool between it and the plate. By containing the molten metal, the weld is shaped to create a neat join that is invisible and smooth.
When finished, the ferrule must be removed. Because they are ceramic, an operator easily chips away the ferrules to expose the finished weld.
They are essential, but there are some stud welding processes where they are not used, like short cycle stud welding that uses inert shielding gas in place of ferrules. It keeps contaminants in the air from affecting the molten metal, changing its properties and potentially weakening the weld. Likewise for capacitor discharge stud welding, because the different process eliminates the risk of molten metal spreading beyond the stud.
The simplest way to get ceramic ferrules for your drawn arc process is to order your drawn arc studs from Shanghai Ceratek Advance Ceramic Technology Co., Limited. All our DA studs, regardless of diameter or material, come with ceramic ferrules, so no need to pay extra for them because they’re an important part of the process.