Characterization, nanomechanical, and wear attributes of sintered Al–TiB2 composites
Olusoji Oluremi Ayodele, Bukola Joseph Babalola, Peter Apata Olubambi
Abstract
Herein, Al–TiB 2 composites ranging from 2 to 8 wt.% TiB 2 addition developed through a Turbula mixer and fast-assisted sintering technology were investigated. The distinct phases and morphologies of the fabricated compacts were assessed via the X-ray diffractometer and scanning electron microscope. The mechanical and wear properties of the fabricated compacts were evaluated. The dispersal of TiB 2 particles and the formation of an interface phase were noticed on the microstructure of the fabricated specimens. The diffractogram confirmed the presence of the TiB 2 phase and Al 5 Ti 3 phase at the plane (002), corresponding to the 2-theta value of 44.9°. The relative density of the fabricated specimens indicated an average of 99.33%, while the microhardness values were in the range of 33.1–41.3 HV1. Adding the TiB 2 particle to the Al matrix raised the tensile strength value to 140 MPa on account of good dispersion of the TiB 2 particle restricting the dislocation movement in the composites, further strengthening the Al–TiB 2 composites at the cost of its ductility. The nanoindentation values (elastic modulus and hardness) of the fabricated Al–TiB 2 composites improved compared to the fabricated Al matrix. TiB 2 improved the wear properties of the fabricated Al–TiB 2 composites by lowering it. Delamination, oxidation, and adhesion wear mechanisms are the noticeable wear observed from the fabricated Al–TiB 2 composites. The image of the fractured Al–TiB 2 composites depicts dimples and microvoids, which are the characteristics of ductile fractures.