Mechanically alloyed Al7075-TiC nanocomposite: Powder processing, consolidation and mechanical strength

This work aimed to fabricate high strength Al7075-TiC nanocomposite by mechanical alloying (MA) followed by hot pressing considering preparation parameters. The effect of milling time on the microstructure of the synthesized powder was characterized by means of X-ray diffraction measurements (XRD) and scanning electron microscopy (SEM). Subsequently, the integrated effects of three major parameters including milling time (10, 30 and 50 h), hot pressing temperature (350, 400 and 450 °C) and pressure (400, 500 and 600 MPa) were investigated on the microhardness. Improved sintering and mechanical properties were achieved by increasing hot pressing temperature and pressure; while rising temperature over 400 °C resulted in reduced hardness due to severe grain growth during hot pressing. More interestingly, influence of milling time on the mechanical properties was strongly depended on the hot pressing pressure value. Furthermore, tensile strength of ∼725 MPa was obtained by consolidation under optimal parameters.