Investigation of wear behavior of Al-B₄C functionally graded materials synthesized using vibration-assisted casting methodology

Abstract

This study investigates the dry sliding reciprocating wear behavior of Al-B4C continuous functionally graded materials at two different loads, 15 and 25 N, against a steel ball in a ball-on-flat configuration at a frequency of 5 Hz. Using sound wave-assisted vibrational casting, three samples with composition ratios of 2, 4, and 6 volume percentages in an aluminum matrix were produced, and a comparative analysis was conducted between them and their respective zones. Tribological properties and microstructure were examined for the inner (A), middle (B), and outer (C) regions of each sample, and subsequent analysis revealed that wear rate and friction coefficient increased with increasing applied load, but decreased with increasing sliding distance (100, 200, and 300 m). Also, as the concentration of B4C reinforcing particles increased, the wear rate and friction coefficient gradually decreased from the inner to the outer region of each sample. In comparison to the middle (B) and inner (A) regions, the outer (C) region of each sample exhibited superior wear properties. At high applied normal loads, the worn morphologies of wear tracks examined with a scanning electron microscope and an optical profilometer revealed extreme delamination wear and particle pull-out.