Effect of ZrB2 and ZrC and mixing method on Mechanical properties and wear behaviour of Al7075 based composites for aircraft aerofoil surfaces

Abstract

Developing lightweight materials with notable properties for aerospace applications is a great challenge. The impact of ZrB₂ and ZrC reinforcement on the mechanical and wear behaviour of stir-cast Al7075-ZrB₂-ZrC composites is investigated with a weight percentage of 2, 4, 6 and 8 % ZrB₂, and fixed 2 % ZrC. The results showed notable improvements with a hardness of 96 HRB, tensile strength of 423 MPa and compressive strength of 385 MPa; hardness increased by 14 %, tensile strength increased by 11 % and compressive strength was enhanced by 13 % when compared with pure Al7075. The wear behaviour has been analysed by pin-on-disc wear test at room temperature with loads of 10 N and 20 N against the sliding distance of 400 m to 1200 m; the wear resistance is improved by 17 % and CoF is reduced by 11 % compared to pure Al7075. SEM micrographs display the wear mechanism and microstructural changes happened during the wear test. Al7075-ZrB₂-ZrC composites are the optimum replacement for aerofoil surfaces because of their remarkable properties.