“Steel–Copper” Natural Thermocouple for Friction-Welding Technologies

The possibilities of obtaining an integral connection of copper structures by friction welding with mixing used in the manufacture of inverter coolers for traction electric drives have been experimentally investigated. Welding quality is ensured by continuous temperature control at the point of contact of the parts as a feedback method for the welding-tool control system. A method of direct temperature measurement by the thermal EMF method has been tested, this being the most objective and fast-acting solution as compared with temperature sensors of the contact and optical principle of operation. A correctness of the measurement sufficient to control the welding mode and ensuring the repeatability of the results, as well as the technical possibility of implementing such feedback by general industrial measuring instruments, has been proved.