Enhanced mechanical and wear properties of novel AlMgB14 intermetallic reinforced aluminum matrix nanocomposite

Abstract

Aluminum matrix composites are the most promising materials in various industries, such as automobiles and aerospace. However, their usage may be limited due to their low strength and low wear resistance in some functional applications. In this study, a novel aluminum matrix nanocomposite with desirable strength and tribological properties was synthesized by mechanical milling and hot-pressing. AlMgB₁₄ (called BAM) intermetallic with an average particle size of 32 nm was employed as the reinforcement (with different amounts of 0, 1, 3, and 5 wt%) in the aluminum matrix for the first time, aiming to improve the strength and wear resistance. The specimens were characterized by X-ray diffractometer (XRD), field-emission scanning electron microscope (FESEM), energy dispersive spectrum (EDS), hardness, compressive strength, and dry sliding testing. The results demonstrated that by increasing the BAM percentage, a significant enhancement in the mechanical properties and wear resistance of the aluminum matrix is achieved. The nanocomposite sample, which contains 5 wt% BAM nanoparticles exhibited a remarkable enhancement in microhardness (a 124 % improvement), yield strength (a 168 % increase), and ultimate strength (a 149 % increase) compared to the unreinforced aluminum sample. Furthermore, this sample demonstrated the best wear performance, with a 65 % reduction in coefficient of friction and an 82 % reduction in wear rate. The advancement in wear assessment can be attributed to the development of a mechanically milled layer (MML) on the surface subjected to wear. The findings highlight the suitability of the BAM intermetallic compound for enhancing the comprehensive properties of composites, particularly aluminum matrix composites.