Aluminium-Based Dissimilar Alloys Surface Composites Reinforced with Functional Microparticles Produced by Upward Friction Stir Processing

Abstract

Surface metal matrix composites offer an excellent solution for applications where surface properties play a crucial role in components’ performance and durability, such as greater corrosion resistance, better wear resistance, and high formability. Solid-state processing techniques, such as friction surfacing and friction stir welding/processing, offer several advantages over conventional liquid-phase processing methods. This research investigated the feasibility of producing surface composites of aluminium-based dissimilar alloys reinforced with functional microparticles through experimental validation, determined the process parameters that resulted in a more homogeneous distribution of the particles in the surface composites, and enhanced the understanding of Upward Friction Stir Processing (UFSP) technology. The production of aluminium-based dissimilar alloys (AA 7075-T651 and AA 6082-T651) surface composites reinforced with SiC particles was studied, and it was concluded that the macrography and micrography analyses, scanning electron microscopy (SEM) analysis, microhardness measurements, and eddy currents technique reveal an extensive and homogeneous incorporation of SiC particles. In the stirred zone, a decrease of approximately 20 HV 0.5 in hardness was observed compared to the base material. This reduction is attributed to the weakening effect caused by low-temperature annealing during UFSP, which reduces the strengthening effect of the T651 heat treatment. Additionally, the presence of particles did not affect the surface composite hardness in the stirred zone. Furthermore, despite the presence of significant internal defects, SEM analyses revealed evidence of the lower alloy merging with the upper zone, indicating that the lower plate had a role beyond being merely sacrificial. Therefore, the production of bimetallic composites through UFSP may offer advantages over composites produced from a monometallic matrix. The results of the eddy currents testing and microhardness measurements support this finding and are consistent with the SEM/EDS analyses.

Enabling electrical response through piezoelectric particle integration in AA2017-T451 aluminium parts using FSP technology

“…These studies specifically focus on integrating piezoelectric particles into aluminium parts (AA2017-T451) using FSP technology, utilizing BT and PZT particles to enhance the sensitivity and technical aspects of the resulting SSM. Different FSP variants, such as those presented by Vidal et al [46] and Moreira et al [47], allow particle incorporation in the metallic matrix. Metallographic assessments and mechanical property evaluations were conducted to analyse particle distribution, concentration, and their impact on the base material's mechanical behaviour.…”

Microstructural and Mechanical Characterization of the Dissimilar AA7075 and AA2024 Aluminum Alloys Reinforced with Different Carbide Particles Welded by Friction Stir Welding

“…Dissimilar aluminum composites are fabricated through the amalgamation of two or more distinct varieties of aluminum alloys. Various alloys can be selected to enhance the characteristics of the composite, including, but not limited to, strength, stiffness, and corrosion resistance [3][4][5]. The mechanical characteristics of dissimilar aluminum composites produced using FSW are influenced by many parameters: the selection of aluminum alloys, the manipulation of processing parameters (e.g., tool rotation speed, welding speed, and plunge depth), and the characterization of the resulting microstructure in the composite material [6][7][8][9].…”

Introduction of Coal Reinforcing Particles on the Dissimilar FSW AA608/AA5083 Joint via Friction Stir Processing

“…In recent years, researchers have increasingly explored innovative methodologies to improve these joints through the integration of reinforcing agents. This incorporation of reinforcing agents via FSP into aluminum alloys is a fundamental component of the broader concept known as friction stir processing of advanced metal matrix composites (FSP AMMCs) [3,4]. These reinforcing agents can take the form of particles, fibers, or other materials, imparting added mechanical, thermal, or functional attributes to the base metal.…”

“…These reinforcing agents can take the form of particles, fibers, or other materials, imparting added mechanical, thermal, or functional attributes to the base metal. In the context of aluminum alloys, FSP AMMCs entail introducing nanoparticles, ceramic particles, carbon-based materials, or other strengthening agents into the aluminum matrix [4,5]. The FSP process uniformly disperses these reinforcing agents throughout the material, leading to improved mechanical properties such as increased strength, enhanced wear resistance, and improved thermal stability.…”