Development and mechanical-wear characterization of Al2024-nano B 4 C composites for aerospace applications

Abstract

In the current research, the production of composites, characterization, mechanical and wear behavior of 5 and 10 wt.% of nano composites have been investigated by reinforcing the nano B₄C ceramic particulates into Al2024 alloy. The composites were prepared by using two stage stir casting technique containing Al2024 alloy as a matrix phase and nano B₄C particulates as reinforcement. After the composite preparation, the prepared composite material was examined by using various techniques such as SEM, EDS and XRD for characterizing the chemical elements and microstructures of reinforced and unreinforced material. Later, the mechanical properties and wear behavior of as cast Al2024 alloy and Al2024 −5 and 10 wt.% nano B₄C composites were studied. Different mechanical properties such as hardness, percentage elongation, ultimate and yield strength were evaluated as per the ASTM standards. The dry sliding wear tests were conducted by using pin on disc equipment. The experiments were conducted for the sliding distance of 3000 m by varying the sliding speed and load. It was found that due to the addition of nano B₄C ceramic particles in the Al2024 alloy matrix, the hardness, ultimate tensile strength and yield strength of the prepared composites were increased and the percentage elongation was decreased. Furthermore, there was an improvement in the volumetric wear loss with respect to the speed, load, and sliding distance for all the prepared composite materials. However, with the addition of nano B₄C ceramic particulates in the base Al2024 matrix, the volumetric wear loss was decreased. The scanning electron microscope was used to study and analyze the fractography and different wear mechanisms for various test conditions of different compositions, tensile fractured surfaces and worn surfaces.