Electric Arc Spray
What is Electric-Arc Spray?
Like flame spray, electric-arc spray was invented in the early 20th century. Even though the technology has been around for a long time, it still remains a very powerful thermal spray technology. Electric-arc spray uses a simple, low power arc drawn between two electrically charged wires. Arc spray equipment resembles GMAW (MIG) welding equipment, in the power source and wire feeding units. Common arc spray units are capable of spraying iron and copper alloys at rates up to 40 lbs./hr (18 Kg/hr.) using only 12 kW (42 MJ) of electricity. Electric-arc spraying produces the fastest coating rates of any technology. Electric-arc spray devices are thermally efficient and, because there is no flame or plasma, little heat is transferred to the part being coated.
Download Electric-Arc Spray Device Video (2.46 MB)
Materials
Electric-arc spray is limited to materials that are electrically conductive and can be made into wire form. It is possible to spray some materials that can not be made into wire, by incorporating them into the core of hollow conductive wires. Materials such as carbides have been successfully deposited with electric-arc spraying using cored wire technology. The carbide materials are then deposited with the metal wire housing to provide improved wear resistance as a cermet, (ceramic/ metal composite) coating.
Industries
Like most of the thermal spray processes electric-arc spray can be found in many diverse industries. It is commonly used in automotive, aerospace, defense, infrastructure, and even in the industry of art.
Applications
A common application for electric-arc spray is in the automotive industry. The technology is used to replace lead to hide seems between body panels, by filling the gap with metal and then finishing coating smooth to hide the seam. The technology has been used to coat large objects such as bridges, where aluminum and zinc are deposited to provide corrosion resistance. Electric-arc spraying has also become a favorite tool for artist in the creation of artistic sculptures. Spraytime article