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promising material for automotive, aerospace, and structural engineering applications [1–3]. Depending upon the desired application, metal matrix composites can
be reinforced with various reinforcements such as metal carbides, metal oxides,
nitrides, and metal borides [4]. Over the past decade, carbonaceous reinforcement
like carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) have attracted
considerable attention as the promising reinforcements in the metal matrix due to
their lucrative mechanical, chemical, electrical, and thermal properties. CNTs/GNPs
reinforced metal matrix nanocomposites exhibit remarkable properties, such as high
Young’s modulus, high tensile strength, low densities, high strength to weight ratio,
and possess excellent resistance to wear and corrosion. These attractive properties
make CNTs/GNPs matrix nanocomposites a potential candidate for high strength
structural and surface engineering applications [5–7]. Graphene nanoplatelets and
carbon nanotubes are used as reinforcement in various metallic matrices such as
copper [8, 9], titanium [10, 11], aluminum [12, 13], magnesium [14, 15], and nickel
[16, 17].
Previously, CNTs reinforced metal matrix composites were processed using
various processing routes such as powder metallurgy, melting and solidification,
electrochemical deposition, and other novel techniques like molecular level mixing
and nanoscale dispersion process. Results indicated improvement in the mechanical
and tribological performance of CNTs/GNPs reinforced metal matrix composites
over monolithic base metals [2, 18]. However, the utilization of carbon nanotubes
and graphene nanoplatelets as a reinforcement in the metal matrix to its full potential
is still a major bottleneck due to numerous obstacles. It is a challenging task to achieve
uniform dispersion of CNTs/GNPs into the metal matrix due to its agglomeration
resulting from strong, cohesive van der Waals forces. [5–7]. Another difficulty is to
form a stable, strong interfacial bonding alongside retaining the structural integrity
of the reinforcement, which effectively promotes the load transfer from the matrix to
the reinforcement. Several attempts have been made previously to effectively overcome the challenges involved with the dispersion of CNTs/GNPs within the metal
matrix without affecting the structural integrity of the carbonaceous reinforcement
[19, 20]. Nickel exhibits various attractive properties such as ductility, toughness,
and excellent resistance to wear corrosion and oxidation. Nickel and nickel-based
superalloys are in use in many automotive, aerospace, and various other industries
owing to the excellent properties and its ability to retain its shape at higher temperatures [4]. Also, studies demonstrated improvement in the mechanical properties of
nickel matrix when reinforced with carbonaceous reinforcement, as nickel exhibits
good wettability for carbon and does not form an equilibrium carbide phase [17, 21].
Therefore, to enhance the properties and to compensate for the limitations of monolithic nickel metal, CNTs with high aspect ratios and GNPs with the large surface area
are proposed to be better reinforcement material in the ductile nickel metal matrix.
Moreover, the CNT and GNP reinforcement also act as a solid lubricant, considerably
reducing the coefficient of friction and improving tribological performance [16, 21].
Several studies investigated the effects of carbonaceous nanomaterials as high
strength reinforcement in the metal matrix nanocomposites. Results indicated that
homogeneous dispersion of carbonaceous reinforcement in the nickel matrix without
A. Patil et al.
promising material for automotive, aerospace, and structural engineering applications [1–3]. Depending upon the desired application, metal matrix composites can
be reinforced with various reinforcements such as metal carbides, metal oxides,
nitrides, and metal borides [4]. Over the past decade, carbonaceous reinforcement
like carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) have attracted
considerable attention as the promising reinforcements in the metal matrix due to
their lucrative mechanical, chemical, electrical, and thermal properties. CNTs/GNPs
reinforced metal matrix nanocomposites exhibit remarkable properties, such as high
Young’s modulus, high tensile strength, low densities, high strength to weight ratio,
and possess excellent resistance to wear and corrosion. These attractive properties
make CNTs/GNPs matrix nanocomposites a potential candidate for high strength
structural and surface engineering applications [5–7]. Graphene nanoplatelets and
carbon nanotubes are used as reinforcement in various metallic matrices such as
copper [8, 9], titanium [10, 11], aluminum [12, 13], magnesium [14, 15], and nickel
[16, 17].
Previously, CNTs reinforced metal matrix composites were processed using
various processing routes such as powder metallurgy, melting and solidification,
electrochemical deposition, and other novel techniques like molecular level mixing
and nanoscale dispersion process. Results indicated improvement in the mechanical
and tribological performance of CNTs/GNPs reinforced metal matrix composites
over monolithic base metals [2, 18]. However, the utilization of carbon nanotubes
and graphene nanoplatelets as a reinforcement in the metal matrix to its full potential
is still a major bottleneck due to numerous obstacles. It is a challenging task to achieve
uniform dispersion of CNTs/GNPs into the metal matrix due to its agglomeration
resulting from strong, cohesive van der Waals forces. [5–7]. Another difficulty is to
form a stable, strong interfacial bonding alongside retaining the structural integrity
of the reinforcement, which effectively promotes the load transfer from the matrix to
the reinforcement. Several attempts have been made previously to effectively overcome the challenges involved with the dispersion of CNTs/GNPs within the metal
matrix without affecting the structural integrity of the carbonaceous reinforcement
[19, 20]. Nickel exhibits various attractive properties such as ductility, toughness,
and excellent resistance to wear corrosion and oxidation. Nickel and nickel-based
superalloys are in use in many automotive, aerospace, and various other industries
owing to the excellent properties and its ability to retain its shape at higher temperatures [4]. Also, studies demonstrated improvement in the mechanical properties of
nickel matrix when reinforced with carbonaceous reinforcement, as nickel exhibits
good wettability for carbon and does not form an equilibrium carbide phase [17, 21].
Therefore, to enhance the properties and to compensate for the limitations of monolithic nickel metal, CNTs with high aspect ratios and GNPs with the large surface area
are proposed to be better reinforcement material in the ductile nickel metal matrix.
Moreover, the CNT and GNP reinforcement also act as a solid lubricant, considerably
reducing the coefficient of friction and improving tribological performance [16, 21].
Several studies investigated the effects of carbonaceous nanomaterials as high
strength reinforcement in the metal matrix nanocomposites. Results indicated that
homogeneous dispersion of carbonaceous reinforcement in the nickel matrix without