Research progress of nanoparticles reinforced composite filler metal

Composite filler metal refers to the traditional filler metal by adding a certain proportion of various forms of superalloy, carbon fiber and ceramic particles as reinforcement phase. Due to the addition of the reinforcement phase, the filler metal can have a suitable thermal expansion coefficient, which can effectively reduce the residual stress at the brazing joint caused by the different thermal expansion coefficients of the base metal and improve the comprehensive performance of the brazing joint. In recent years, with the progress of science and technology, the research on nanomaterials has been deepening, and nanomaterials are widely used in the modification of composite filler metals because of their special surface effect, small size effect, quantum size effect and macroscopic quantum tunneling effect. The modification performance of different composite solders by nanoparticles in recent years is reviewed, the advantages and disadvantages of nano-reinforced composite solders are analyzed, and the future research direction of composite solders is prospected.