Study on nanosized Al2O3 and Al2O3-SiC on mechanical, wear and fracture surface of Al7075 composites for soil anchoring applications

Mechanical and tribological tests of aluminium 7075 alloy, mono-composite (Al7075 + 1 % Al₂O₃), and hybrid composite (Al7075 + 1 % Al₂O₃ + 1 % SiC) have been performed in this study according to ASTM standards. Through the stir casting process, mono and hybrid composite materials were prepared. It was discovered that adding more hard ceramic particles improved hardness and strengthened tensile strength. In contrast to Al7075 alloy, hybrid MMCs enhanced tensile strength and superior hardness. The obtained results indicate that highest hardness of 78 VHN and tensile strength of 126 MPa were achieved for developed hybrid composites. A pin-on-disc wear test rig was used to conduct wear experiments. The Taguchi approach was used to optimise the wear parameters. The findings showed that the load had a greater impact on the wear behaviour of Al7075 alloys than did sliding distance and speed. The wear behaviour in mono composites and hybrid composites was improved by the addition of nano sized Al₂O₃ and SiC particulates to Al7075. Improved wear resistance for monolithic, mono and hybrid composites was achieved at 5 N of load, 100 rpm of speed and 250 m of sliding distance. Abrasion and adhesion-related damages were discovered by micrograph studies. Flows with the deep grooves were observed on the worn-out surface of mono composite. It provided the evidence of the mono composites' abrasive mechanism. Comparing the hybrid MMCs to the monolithic and mono composite MMCs it was seen that, the hybrid composites (Al7075 + 1 % Al₂O₃ + 1 % SiC) exhibited better wear resistance.