Microstructure and tensile properties of in situ TiCp/Al–4.5 wt.% Cu composites obtained by direct reaction synthesis

Al–4.5 wt.% Cu matrix composites reinforced by in situ TiC particles have been synthesized by direct reaction synthesis (DRS). The microstructure and tensile properties of the in situ composites have been examined by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), and optical microscopy. The results show that the formation of an Al3Ti phase was effectively reduced when the Al content was up to 10 wt.% in the preform. The size of the in situ spherical TiC particles in the matrix was about 2–3 μm. The elongation of the in situ TiC/Al–4.5 wt.% Cu composites was up to 12.3%. The improved tensile properties are attributed to grain refinement of the matrix, a high density of dislocations, and successful suppression of the Al3Ti phase.

Research highlights▶ The elongation of the in situ composites was up to 12.3%. ▶ 10 wt.% Al in the preform helped to suppress the formation of an Al3Ti phase. ▶ A high density of dislocations was very easily observed in the microstructure.