Effect of incremental hot rolling on electrical, thermal and mechanical properties of erbium-reinforced 7085AA/ ZrB2-Al2O3 nanocomposites for high temperature structural applications

Due to its suitability for prolonged usage, the structurally stable 7085 aluminium alloy (7085AA) has gained significant attention in industrial sectors such as aeronautical, automobile, electrical transmission and high- temperature applications. The main objective of the current work is to fabricate and investigate 7085AA reinforced with ceramic nanoparticles (AZ) such as Zirconium diboride (ZrB2), Aluminium oxide (Al2O3) and the rare earth metal Erbium (Er). This study aims to enhance the electrical, thermal and mechanical properties by varying the number of hot-rolling passes. The concentration of AZ and Er was kept at 1.0 and 0.3 wt% in the 7085AA composites, respectively. The Er-reinforced 7085AA/AZ composites was fabricated through an In-situ process, and then subjected to post processing and T6 heat treatment. The best characteristics of Er-reinforced 7085AA/ AZ composites obtained in this study, irrespective of number of hot rolling passes, are as follows: Electrical conductivity- 23.22 f 0.03 MS/m, Thermal conductivity- 150.6 f 0.7 W/mK, Hardness- 230.14 f 3.6 HV and Ultimate tensile strength- 546.1 f 3.3 MPa. The Electrical and thermal conductivity of single-pass composites were found to be superior, whereas triple-pass composites showed prominent enhancement in mechanical properties. It is concluded that the electrical, thermal and mechanical strength of Er-reinforced 7085AA/AZ composites can be achieved by tweaking the number of hot rolling pass.