Tribological characteristics of friction stir processed graphite and tin/LM24 surface composites

Abstract

Friction stir processing (FSP) is an emerging solid-state technique for preparing surface composites using various reinforcements. Ceramics and metallic particles are easily reinforced in a matrix by this technique. Surface composites made from an LM24 alloy reinforced with graphite and tin, with good wettability and material flow owing to the low melting point of tin, were fabricated by FSP at two rotational speeds of 1,400 and 1,000 rpm. Despite its low hardness, the graphite/LM24 surface composite fabricated at a higher rotational speed of 1,400 rpm exhibited better wear resistance. However, its frictional behavior was not significantly affected by the reinforcement. The fabricated surface composites with graphite and tin reinforcement as well as graphite-only reinforcement exhibited contradicting behaviors under sliding wear conditions. The post wear analysis indicated that abrasion, adhesion, layer formation, and delamination occurred on the composite surfaces.

Optimization of friction stir processing parameters for improving structural and mechanical properties in in situ AA5083-H111/Al–Fe composites

“…10,11 Indeed, a solid-state process that can provide strong interfacial strength between fine reinforcements and Al-alloy while maintaining homogenous reinforcement dispersion has to be developed. 12,13 FSP in situ composites have shown the ability to achieve better interfacial bonding through in situ reactions. This results in superior mechanical characteristics because of the even distribution of smaller reinforcing particles created in situ.…”

“…However, various other processing practices (sintering, casting, microwave synthesis and mechanical alloying are used to fabricate in situ aluminium composites. [12][13][14][15] However, these process techniques require very expensive devices and consume excessive energy. In recent years, several investigations regarding FSP for in situ formation of MMCs were reported.…”

Mechanical, machining and corrosion properties of Al5083‐carbon nanotubes composite produced by friction stir processing

“…Friction stir processing is a solid state processing technique used to develop fine grained metal matrix composites without melting the matrix material [1, 3]. The mechanism behind development of fine grains during friction stir processing has been demonstrated elsewhere [4]. Several alloys of magnesium, aluminum, copper, titanium and steels have been used as matrix materials to develop composites by dispersing different carbides, nitrides and oxides graphene, carbon nanotubes, hydroxyapatite, fly ash, metallic powders, etc.…”