Compression behaviour and strengthening mechanisms for Cu hybrid composites.

In this investigation, Cu-TiO₂-Graphite hybrid composites were fabricated with variations in wt.% of TiO₂ and fixed wt.% of Graphite contents through stir casting technique. The size of the grains measured after casting were 83 ± 04, 64 ± 10, 41 ± 10 and 29 ± 04 μm for 0, 3, 6, and 9 wt% hybrid composites, respectively. The addition of 1 wt.% graphite (Gr) was not only to enhance the mechanical and tribological properties but also to improve the wettability during casting. The influence of TiO₂ and Gr in Cu-hybrid composite on compression test was investigated followed by characterisation studies involving XRD, EDS, TEM, EBSD. The results reveal that 9 wt% reinforced composite exhibits more strain hardening. Further, composite exhibits higher strength due to the presence of combined strengthening mechanisms such as grain boundary, Orowan and thermal expansion coefficient mismatch in commensurate with ceramic particle addition. Out of these, it is found that Orowan strengthening contributes significantly to the compression strength of the hybrid system investigated. [ABSTRACT FROM AUTHOR]