Synthesis and characterization of in-situ (Al-Al3Ti-Al2O3)/Al dual matrix composite

Aluminum matrix composites (AMCs) with high volume fraction of reinforcement exhibit superior mechanical properties at the expense of ductility. To overcome this shortcoming, a dual matrix composite microstructural design has proven to be beneficial in increasing the ductility while maintaining the optimal strength. In the present investigation, an in-situ dual matrix composite from Al-TiO2 system was successfully fabricated by a mechanical and thermal synthesis process via powder metallurgy route. The in-situ dual matrix composite microstructure comprises of Al-Al2O3-Al3Ti composite regions separated by ductile unmilled outer Al matrix. The composite region provides strength to the dual matrix composite while the outer Al matrix provides plasticity during deformation. The differential scanning calorimetry (DSC) technique was used to analyze the chemical reactions occurring during the synthesis. A comparative study on the microstructure evolution of in-situ single and dual matrix composites was done using XRD, SEM, EDS and EBSD. The in-situ dual matrix composite shows lower microhardness and compressive strength with significant increase in ductility and wear resistance compared to the in-situ single matrix composite with the same amount of reinforcement. (C) 2020 Elsevier B.V. All rights reserved.