Review of Recent Progress in the Development and Properties of Aluminum Metal Matrix Composites Reinforced with Multiwalled Carbon Nanotube by Powder Metallurgy Route

Abstract

Aluminum and its alloys are finding increasing applications in every sphere of industry with various reinforcements. New reinforcements like graphene and carbon nanotubes (CNTs) are in focus on account of its contribution in mechanical, thermal, and electrical properties. Achieving uniform distribution and selecting the right manufacturing process still remain a challenge. Hence, this review takes into account the contributions by many researchers and attempts to consolidate the findings that may close the gap and identify the scope for future research. In spite of the advantages of aluminum, it requires improvement in strength, wear resistance, heat resistance, conductivity, and thermal expansion. Among the available reinforcements, CNT stands out because of its unique features of thermal conductivity, expansion, and strength. The effect of multiwalled CNT reinforcement in metal on precipitation hardening is also discussed.

Processing of an AA7050/Al Hybrid Composites Reinforced with Multiwalled Carbon Nanotubes

“…Generally, metals reinforced with carbon nanotubes have an increase in mechanical strength through different mechanisms. The main mechanisms discussed in the literature about CNT reinforcement are load transfer 39,40 , Orowan's mechanism 1,41 , and thermal expansion mismatch strengthening 9,42 . It is believed that these mechanisms act simultaneously, since neither single mechanism can explain the increase in the mechanical properties verified in these composites 42 .…”

“…The development of lightweight metal composites, such as carbon nanotubes reinforced aluminum matrix (CNT/ Al), allows changes in properties of the pure metal or alloy without adding weight. Several investigations show an improvement in the mechanical properties of pure Al by incorporating carbon nanotubes (CNT) [1][2][3][4] . According to the data evaluated by Jagannatham et al 5 , about 70% of the papers published in CNT/Al composites have pure Al as matrix and 30% have Al alloys as a matrix, due to low cost and easier processing of pure Al.…”

An improved compocasting technique for uniformly dispersed multi-walled carbon nanotube in AA2219 alloy melt

“…The strong physical interfacial bonding is extremely favourable for enhanced load transfer efficiency of the nano-composites from matrix to reinforcement [31][32][33]. Researchers report that [1,2] MWCNT/graphene improves the mechanical properties of cast composite samples. However, increased MWCNT in cast samples did not show an increase in hardness.…”

“…The low density of carbon nanotubes (CNTs), causes dispersion difficult in molten metal. At the melt temperature of 750°C and above, which is the processing temperature of aluminium alloy, the wetting angle between MWCNT and Al is increased above 160° [1]. The poor wettability of carbon by aluminium is the hindrance in casting route to fabricate the nanocarbon reinforced aluminium composites.…”

“…Since 2007 a new trend has been observed in MWCNT reinforcement with lightweight materials [1,2]. Among the lightweight materials aluminium alloy (AA) and magnesium alloys got more attention.…”