Mechanical and Microstructural Characterization of Friction Stir Welded SiC and B4C Reinforced Aluminium Alloy AA6061 Metal Matrix Composites

Abstract

This study focuses on the properties and process parameters dictating behavioural aspects of friction stir welded Aluminium Alloy AA6061 metal matrix composites reinforced with varying percentages of SiC and B4C. The joint properties in terms of mechanical strength, microstructural integrity and quality were examined. The weld reveals grain refinement and uniform distribution of reinforced particles in the joint region leading to improved strength compared to other joints of varying base material compositions. The tensile properties of the friction stir welded Al-MMCs improved after reinforcement with SiC and B4C. The maximum ultimate tensile stress was around 172.8 ± 1.9 MPa for composite with 10% SiC and 3% B4C reinforcement. The percentage elongation decreased as the percentage of SiC decreases and B4C increases. The hardness of the Al-MMCs improved considerably by adding reinforcement and subsequent thermal action during the FSW process, indicating an optimal increase as it eliminates brittleness. It was seen that higher SiC content contributes to higher strength, improved wear properties and hardness. The wear rate was as high as 12 ± 0.9 g/s for 10% SiC reinforcement and 30 N load. The wear rate reduced for lower values of load and increased with B4C reinforcement. The microstructural examination at the joints reveals the flow of plasticized metal from advancing to the retreating side. The formation of onion rings in the weld zone was due to the cylindrical FSW rotating tool material impression during the stirring action. Alterations in chemical properties are negligible, thereby retaining the original characteristics of the materials post welding. No major cracks or pores were observed during the non-destructive testing process that established good quality of the weld. The results are indicated improvement in mechanical and microstructural properties of the weld.

Investigation on Inorganic Salts K2TiF6 and KBF4 to Develop Nanoparticles Based TiB2 Reinforcement Aluminium Composites

“…In recent scenarios, a huge number of research studies has shifted from monolithic materials to composite materials to meet the improving universal demand for high performance, ecofriendly corrosion, erosion, and wear-resistant materials. The improvement of lightweight and fewer costly materials with enriched performance for automobiles, construction, aviation, aircraft, and several engineering applications is always a concern of numerous research workers [ 1 , 2 ]. The foremost goal involved in developing composite (AMC) materials is to merge the ductile matrix metals and hard ceramic particles.…”

Special Issue: Advance in Friction Stir Processed Materials

“…In many industrial applications, aluminium alloys are reinforced with hard ceramic particles to enhance the mechanical properties of aluminium metal matrix composites (Al-MMC). Ali et al [ 15 ] conducted studies on AA6061/SiC/B 4 C composites subjected to friction stir welding. The matrix of the composite was the AA6061 aluminium alloy, while SiC and B 4 C powders were used as reinforcement, whose total share in the composite was 13%.…”

Mechanical properties of AA6061T6 and AA6351T6 plates joined by friction stir welding

“…It has wide application in aircraft's primary structure design, heavy-duty forgings, structural components, space booster tanks, electric vehicles, and marine industries [1][2][3]. However, aluminium alloys are difficult to weld by fusion welding due to the formation of an oxide layer, hot cracking, porosity formation, hydrogen embrittlement during melting, and dendrite structure formation causes severe failure [4][5][6]. So a new welding technique is essential, which improves the welding strength and efficiency of aluminium alloy joints.…”