High strength and high electrical conductivity Cu composites reinforced by SiO2 aerogel particles

Abstract

For high-performance metal matrix composites, maintaining the uniform distribution of the small-sized reinforcement phase in the matrix is the key to fully exploiting the advantages of the reinforcement phase, but it is also a technical difficulty. In this work, a new type of reinforcement phase—SiO2 aerogel particles, was selected to be added into the Cu matrix. Utilizing the characteristics of easy dispersion of the nanoporous structure in its original state and then densification under a high temperature load, its uniform distribution in the Cu matrix can be achieved by a simple powder metallurgy method. The composites have excellent electrical conductivity and high strength, which is mainly attributed to the unique distribution of silica aerogel particles: larger particles are distributed on the grain boundary, and smaller particles are distributed in the grain, which can greatly refine the grain. Quantifying the contribution of various strengthening mechanisms to yield strength increases, the results revealed that the grain refinement strengthening mechanism plays a leading role. Moreover, this work provides a new strategy for preparing high-performance copper matrix composites.