## 2 Review Available Literature
### AA5083-Based MMCs
An AA5083-Ni composite intermetallic was found in the layer. The processed composite did not contain this layer when tiny particles of a similar size (10 \(\upmu\)m) were merged using the same FSP parameters. The outcomes showed that particle ball milling enhanced the composite's microstructure. The ball-milled particle is in a high-energy state because of the interfacial layer formation. In terms of strength, both composites performed better than the unreinforced AA5083. Additionally, FSP reduced the base material's grain size from 25 to 3.5 \(\upmu\)m, resulting in a stronger composite. The strength and ductility of the ball-milled composite with the small Ni particles as received were less than anticipated due to the existence of the interfacial reaction layer. [PERSON] et al. [46] used FSP to create an AA5083-B4C nanocomposite and tribologically characterize it. FSP was used to produce an AA5083 incorporated with boron carbide as a reinforced layer. As reinforcements, nano-sized and micro-sized B4C particles were utilized. Optical microscopy and SEM examinations were used to examine the FSPed surface composite layer. To produce surface composites using FSP, it is important to consider the amount of reinforcement and the number of passes. Before manufacturing, several tests were carried out, and it was found that the constant rotational and transverse speeds were, respectively, 1000 revolutions per minute and 25 mm per minute. Microhardness and tensile tests were used to assess the FSPed surface composite's mechanical characteristics. The outcomes were compared with the base metal's properties. The effects of reinforcement and the number of passes on properties were investigated. To assess the tribological performance of the surface composite, the pin-on-disk test was run. In terms of wear resistance, tensile behaviour, and hardness, the surface composite layer produced in three passes with nanoparticle reinforcement performed better than the base metal. The dispersion of nanoparticles in the base material became more uniform compared to a single-pass FSP nanocomposite, resulting in increased hardness. After three passes, the microhardness of the nanocomposite was raised to 122 Hv. The hard B4C particles placed on the surface of the AA5083 improved the wear resistance of the nanocomposite. When compared to non-reinforced samples, the one-pass approach resulted in significant reductions in yield and UTS values of surface composites. Despite this, the surface composite's microhardness was shown to be larger than that of the unreinforced samples, and the wear rate was also lowered. [PERSON] et al. [47] studied the wear properties of an AA5083-tungsten composite made using the FSP technique. To create metal-particle-reinforced surface composites, FSP was employed to integrate tungsten particles in an AA5083 material. On an AA5083 plate with a thickness of 10 mm, a groove of 60 \(\times\) 2 \(\times\) 1.5 mm was created. Ten-micrometre tungsten particles were maintained in the groove. The FSP tool rotated at 1200 revolutions per minute and had a transverse speed of 24 mm. Wear test samples with a diameter of 8 mm and a height of 10 mm were cut using EDM. The results demonstrated that the microstructure had a homogeneous distribution. The particles were evenly distributed in the base material, and the grain size was refined using FSP. The tungsten particles remained elemental after X-ray diffraction, and an additional investigation did not find an intermetallic peak. The composite surface layer outperformed the base and FSPed alloys in terms of wear resistance. The base and FSPed sample's worn surface inspections revealed that the composite exhibits mild and adhesive oxidative wear at all three loads, transitioning to severe abrasive and delamination-type wear at higher loads. [PERSON] et al. [48] examined the cold formability of boron-carbide particles and carbon nanotubes in friction-stir-processed aluminium composites. The base materials AA5083 and MWCNTs, as well as B4C reinforcements, were used.