Composition design for modified nickel nanopastes containing a low-melting element as additive for pressureless nanojoining

The use of Ni nanopastes for joining applications offers advantages over other methods. However, since it is based on solid-state processes, a pressure must be applied during the joining process, which represents a challenge. To overcome this, a novel concept is presented in this work, which introduces a low-melting additive to the Ni nanopaste. A liquid phase provides the potential to achieve a joint seam formation with both a reduced porosity and better adhesion to the base material without technical pressure during the process. In a comprehensive selection, elements such as Mg, Al, Ge, In, Sn, and Pr are identified as suitable additives. Their properties in binary phase systems with nickel are discussed. A modified Ni nanopaste with Ge as additive was used in promising initial experiments, which is a good starting point for further investigations.