Microstructure, mechanical, and wear properties evaluation of Al-Cu based composite using RHA as reinforcement

Abstract

ABSTRACT This study utilised a two-step stir-cast technique to fabricate Aluminium-based composites reinforced with 5% wt Copper (Cu) and varying weight percentages (1–4% wt) of Rice husk ash (RHA). Our work investigated the role of RHA reinforcement on the microstructure, mechanical properties, and wear characteristics of AlCuRHA composite. Characterisation of the composites and fracture surfaces was performed utilising SEM. The hardness and tensile properties were evaluated. Wear was conducted on the composites in dry and wet conditions using H2SO4 as the medium. The microstructure revealed the homogeneous distribution of the RHA within the AlCu matrix. The hardness of reinforced AlCu is enhanced from 54.24 Hv to 122.74 Hv with an increment of RHA reinforcement from 0 to 4%. The Ultimate tensile (UTS) and specific strengths were noted to increase with increased RHA content from 1 to 4% wt. The ductility levels were reduced with the increase in RHA content. The RHA-reinforced AlCu composite exhibits mixed ductile and brittle fracture modes. The composites with RHA exhibited greater wear resistance. Compared to the dry condition, the composites exhibited improved wear resistance in the acidic environment. The composite with 4 wt% RHA exhibited the lowest wear rates regardless of the environment.