Pradeep Menezes | University of Wisconsin Milwaukee (original) (raw)
Papers by Pradeep Menezes
Self-lubricating metal matrix composites (SLMMCs) are an important category of engineering materi... more Self-lubricating metal matrix composites (SLMMCs) are an important category of engineering materials that are increasingly replacing a number of conventional materials in the automotive, aerospace, and marine industries due to superior tribological properties. Implementing self-lubricating composites into different operating systems is a solution to reduce the use of external toxic petroleum-based lubricants at sliding contacts in a way to help the environment and to reduce energy dissipation in industrial components for strategies toward energy efficiency and sustainability. In SLMMCs, solid lubricant materials including carbonous materials, molybdenum disulfide (MoS2), and hexagonal boron nitride (h-BN) are embedded into the metal matrices as reinforcements to manufacture a novel material with an attractive self-lubricating properties. Due to their lubricious nature, these solid lubricant materials have attracted researchers to synthesize lightweight self-lubricating metal matrix composites with superior tribological properties. This chapter focuses on the recent development in tribological behavior of self-lubricating metal matrix (aluminum, copper, magnesium, and nickel) composites. It is important to note that the tribological parameters, such as normal load, sliding speed, and temperature vary on a wide range and also the counterface materials differ in different experimental tests, comparing the results of tribological behavior of different self-lubricating composites is extremely difficult. In this chapter, attempts have been made to summarize the tribological performance of various SLMMCs as a function of several tribological parameters. These parameters include material parameters (size, shape, volume fraction, and type of the reinforcements), mechanical parameters (normal load and sliding speed), and physical parameters (temperature and environment). The mechanisms involved for the improved mechanical and tribological performances are discussed.
Tribology for Scientists and Engineers, 2013
Metal matrix composites (MMCs) are an important class of engineering materials that are increasin... more Metal matrix composites (MMCs) are an important class of engineering materials that are increasingly replacing a number of conventional materials in the automotive, aerospace, marine, and sports industries due to their lightweight and superior mechanical properties. In MMCs, nonmetallic materials are embedded into the metals or the alloys as reinforcements to obtain a novel material with attractive engineering properties, such as improved ultimate tensile strength, ductility, toughness, and tribological behavior. In this chapter, an attempt has been made to summarize the tribological performance of various MMCs as a function of several relevant parameters. These parameters include material parameters (size, shape, volume fraction, and type of the reinforcements), mechanical parameters (normal load and sliding speed), and physical parameters (temperature and the environment). In general, it was shown that the wear resistance and friction coefficient of MMCs are improved by increasing the volume fraction of the reinforcements. As the normal load and sliding speed increase, the wear rate of the composites increases and the friction coefficient of the composites decreases. The wear rate and friction coefficient decrease with increasing temperature up to a critical temperature, and thereafter both wear rate and friction coefficient increase with increasing temperature. The nano-composites showed best friction and wear performance when compared to micro-composites.
In the present investigation, aluminum matrix nanocomposites reinforced by graphene nanoplatelets... more In the present investigation, aluminum matrix nanocomposites reinforced by graphene nanoplatelets were synthesized by powder metallurgy method. The microstructure of the Al-Graphene nanoplatelets sample was investigated by TEM. The hardness measurements of these samples were investigated using a Rockwell hardness tester. To investigate the tribological behavior of aluminum matrix composites reinforced by graphene nanoplatelets and pure aluminum, pin-on-disk experiments were conducted on the prepared samples. In the experiments, the influence of reinforcement, volume fraction, normal load, and sliding velocity on the tribological performance was investigated. Results showed that the wear rate of Al-1wt.% GNP is increased with increasing normal loads. However, the coefficient of friction (COF) of the Al-1wt.% GNP decreased with increasing normal loads. Formation of graphene film on the worn surface of Al-1wt.% GNP sample and morphology of the worn surfaces of aluminum and composite samples were analyzed by Optical Microscope (OM) and Scanning Electron Microscope (SEM). It was found that the graphene nanoplatelets reinforced nano-composites showed superior tribological properties and demonstrated the ability of the self-lubricating nature of the composite during tribological conditions.
Rapid innovation in nanotechnology in recent years enabled development of advanced metal matrix n... more Rapid innovation in nanotechnology in recent years enabled development of advanced metal matrix nanocomposites for structural engineering and functional devices. Carbonous materials, such as graphite, carbon nanotubes (CNT’s), and graphene possess unique electrical, mechanical, and thermal properties. Owe to their lubricious nature, these carbonous materials have attracted researchers to synthesize lightweight self-lubricating metal matrix nanocomposites with superior mechanical and tribological properties for several applications in automotive and aerospace industries. This review focuses on the recent development in mechanical and tribological behavior of self-lubricating metallic nanocomposites reinforced by carbonous nanomaterials such as CNT and graphene. The review includes development of self-lubricating nanocomposites, related issues in their processing, their characterization, and investigation of their tribological behavior. The results reveal that adding CNT and graphene to metals decreases both coefficient of friction and wear rate as well as increases the tensile strength. The mechanisms involved for the improved mechanical and tribological behavior is discussed.
Self-lubricating metal matrix composites (SLMMCs) are an important category of engineering materi... more Self-lubricating metal matrix composites (SLMMCs) are an important category of engineering materials that are increasingly replacing a number of conventional materials in the automotive, aerospace, and marine industries due to superior tribological properties. Implementing self-lubricating composites into different operating systems is a solution to reduce the use of external toxic petroleum-based lubricants at sliding contacts in a way to help the environment and to reduce energy dissipation in industrial components for strategies toward energy efficiency and sustainability. In SLMMCs, solid lubricant materials including carbonous materials, molybdenum disulfide (MoS2), and hexagonal boron nitride (h-BN) are embedded into the metal matrices as reinforcements to manufacture a novel material with an attractive self-lubricating properties. Due to their lubricious nature, these solid lubricant materials have attracted researchers to synthesize lightweight self-lubricating metal matrix composites with superior tribological properties. This chapter focuses on the recent development in tribological behavior of self-lubricating metal matrix (aluminum, copper, magnesium, and nickel) composites. It is important to note that the tribological parameters, such as normal load, sliding speed, and temperature vary on a wide range and also the counterface materials differ in different experimental tests, comparing the results of tribological behavior of different self-lubricating composites is extremely difficult. In this chapter, attempts have been made to summarize the tribological performance of various SLMMCs as a function of several tribological parameters. These parameters include material parameters (size, shape, volume fraction, and type of the reinforcements), mechanical parameters (normal load and sliding speed), and physical parameters (temperature and environment). The mechanisms involved for the improved mechanical and tribological performances are discussed.
Tribology for Scientists and Engineers, 2013
Metal matrix composites (MMCs) are an important class of engineering materials that are increasin... more Metal matrix composites (MMCs) are an important class of engineering materials that are increasingly replacing a number of conventional materials in the automotive, aerospace, marine, and sports industries due to their lightweight and superior mechanical properties. In MMCs, nonmetallic materials are embedded into the metals or the alloys as reinforcements to obtain a novel material with attractive engineering properties, such as improved ultimate tensile strength, ductility, toughness, and tribological behavior. In this chapter, an attempt has been made to summarize the tribological performance of various MMCs as a function of several relevant parameters. These parameters include material parameters (size, shape, volume fraction, and type of the reinforcements), mechanical parameters (normal load and sliding speed), and physical parameters (temperature and the environment). In general, it was shown that the wear resistance and friction coefficient of MMCs are improved by increasing the volume fraction of the reinforcements. As the normal load and sliding speed increase, the wear rate of the composites increases and the friction coefficient of the composites decreases. The wear rate and friction coefficient decrease with increasing temperature up to a critical temperature, and thereafter both wear rate and friction coefficient increase with increasing temperature. The nano-composites showed best friction and wear performance when compared to micro-composites.
In the present investigation, aluminum matrix nanocomposites reinforced by graphene nanoplatelets... more In the present investigation, aluminum matrix nanocomposites reinforced by graphene nanoplatelets were synthesized by powder metallurgy method. The microstructure of the Al-Graphene nanoplatelets sample was investigated by TEM. The hardness measurements of these samples were investigated using a Rockwell hardness tester. To investigate the tribological behavior of aluminum matrix composites reinforced by graphene nanoplatelets and pure aluminum, pin-on-disk experiments were conducted on the prepared samples. In the experiments, the influence of reinforcement, volume fraction, normal load, and sliding velocity on the tribological performance was investigated. Results showed that the wear rate of Al-1wt.% GNP is increased with increasing normal loads. However, the coefficient of friction (COF) of the Al-1wt.% GNP decreased with increasing normal loads. Formation of graphene film on the worn surface of Al-1wt.% GNP sample and morphology of the worn surfaces of aluminum and composite samples were analyzed by Optical Microscope (OM) and Scanning Electron Microscope (SEM). It was found that the graphene nanoplatelets reinforced nano-composites showed superior tribological properties and demonstrated the ability of the self-lubricating nature of the composite during tribological conditions.
Rapid innovation in nanotechnology in recent years enabled development of advanced metal matrix n... more Rapid innovation in nanotechnology in recent years enabled development of advanced metal matrix nanocomposites for structural engineering and functional devices. Carbonous materials, such as graphite, carbon nanotubes (CNT’s), and graphene possess unique electrical, mechanical, and thermal properties. Owe to their lubricious nature, these carbonous materials have attracted researchers to synthesize lightweight self-lubricating metal matrix nanocomposites with superior mechanical and tribological properties for several applications in automotive and aerospace industries. This review focuses on the recent development in mechanical and tribological behavior of self-lubricating metallic nanocomposites reinforced by carbonous nanomaterials such as CNT and graphene. The review includes development of self-lubricating nanocomposites, related issues in their processing, their characterization, and investigation of their tribological behavior. The results reveal that adding CNT and graphene to metals decreases both coefficient of friction and wear rate as well as increases the tensile strength. The mechanisms involved for the improved mechanical and tribological behavior is discussed.