This process is used to join metals without the use of solder. It involves the direct diffusion of molecules from one element into another element and thus the formation of a bond. The prerequisite for a proper diffusion process is to provide smooth contact surfaces of the elements to be joined. In order to significantly accelerate the diffusion process, the components must be heated to a certain temperature and kept at this temperature for the time required for the process to take place. To avoid oxidation of the joining surfaces, the process must be carried out under vacuum to avoid reactions such as surface oxidation during heating.