Examination of microstructure evolution and strengthening mechanisms in an aluminum-based hybrid composite prepared through the spark plasma sintering method

Abstract

A bulk hybrid composite to be potentially used as a foam precursor was produced in this study. TiH2 powder particles along with different concentrations of SiC were mixed with pure Al particles and consolidated through the spark plasma sintering (SPS) method. Bulk samples with nearly full density were successfully produced using the SPS method. During the consolidation process, no additional phases were found within the ceramic particles/matrix interfacial region. Using the ceramic TiH2 and SiC particles as the reinforcement cause notably strengthened the pure Al matrix (37% higher yield strength) without adversely affecting the plasticity, helping retain strain to fracture of about 50% for the sample. The yield strength of the samples was quantitatively approximated by examining their strengthening mechanisms via a number of simplified models available in the literature. The analyses found grain boundary and dislocation strengthening to be the most effective mechanisms for enhancing the strength of the samples; it was also found that the difference between the approximated and experimentally obtained overall yield strength was negligible.