Vijee Kumar

Bio: Vijee Kumar is an academic researcher from Visvesvaraya Technological University. The author has contributed to research in topics: Graphene & Ultimate tensile strength. The author has an hindex of 1, co-authored 5 publications receiving 23 citations. Previous affiliations of Vijee Kumar include Reva Institute of Technology and Management.

Synthesis and characterization of nano graphene and ZrO2 reinforced Al 6061 metal matrix composites

Abstract: The present work explores the microstructural and mechanical properties of Aluminium (Al) Metal Matrix Composites (MMCs) fortified with Zirconium Oxide (ZrO2) and nanographene particles. The composite material is processed by the mix fluid metallurgy course. ZrO2 and graphene is blended in various extents in which ZrO2 (1 wt. %) reinforcement is kept steady and graphene support is varied independently with 0.5 and 0.75 wt. %. Utilizing optical and SEM equipment, micro examination is conveyed and results uncover that uniform circulation of ceramic zirconium dioxide (ZrO2) and graphene particles are found in the as cast Al6061 MMCs. Fourier-Transform Infrared Spectroscopy (FTIR) investigation is done to know the quality and measure of fortification present in composites and notes the energy gap (Eg) obtained as 4.05 eV. Mechanical tests according to ASTM standards were led on the composites viz., tensile strength, yield strength and % elongation to check the properties of Al based MMCs. The consequence of this work is reasoned with a noteworthy improvement in tensile and yield strength values of the processed composites however, the percentage elongation diminishes with the addition of reinforcement content in the fabricated composite.

Development and Mechanical Characterisation of Al6061-Al2O3-Graphene Hybrid Metal Matrix Composites

Abstract: MMC based on aluminium (Al) were produced for light-weight applications especially in aviation and automobile areas. Present paper deals with the fabrication and mechanical performance of AA6061 matrix composites fortified with Al2O3 (alumina) and graphene particulates. Fluid metallurgy method namely stir casting route was employed for fabricating the hybrid composites. Al2O3p and graphene powder are mixed in different weight fractions in which graphene (1 wt. %) particle reinforcement is held consistent and Al2O3 reinforcement is differed freely with 5, 10 and 15 wt. %. Using optical analyser and SEM equipment, microstructural examination is carried out and the result reveals that the graphene and Al2O3 particles prevalently are homogeneously appropriated on the grain limits of Al matrix and Al2O3 particles are disseminated between graphene in the as-cast AA6061 MMC’s. Detailed analysis on investigation of the microstructure and mechanical aspects of Al6061-graphene-Al2O3p composites is presented by following ASTM guidelines; results uncovered that with increment in reinforcement particles, there is an enhancement in the hardness, ultimate strength, yield strength and a decline in the elongation values was however noticed when contrasted with Al6061 alloy. Fractography investigation revealed dimples in unreinforced alloy and the composite.

Wear behavior of Aluminium 6061 alloy reinforced with coated/uncoated multiwalled carbon nanotube and graphene

Abstract: The current study deals with the fabrication and investigation of wear characteristics of Aluminium 6061(Al6061) hybrid metal matrix composites (MMCs) processed through powder metallurgy technique. Al6061 hybrid MMCs involving fixed 2 wt% of coated/uncoated multiwalled carbon nanotubes (MWCNTs) and varying weight percentages of graphene were fabricated through ball milling procedure. To enhance the scattering of MWCNTs in the matrix, MWCNTs were coated by means of copper through electroless deposition method. Dry sliding wear conduct of Al6061 MMCs was investigated using a pin-on-disc wear testing machine. It was found that at lower load, composites exhibited lower wear resistance than base alloy however at higher load, nanocomposites showed higher wear resistance. The research tried to find the effect of higher loads on the wear resistance. The composites were evaluated if they could give out reinforcements at higher loads during wear tests. The wear morphologies were reported using Scanning Electron Microscopy (SEM) and it was noticed that lower load abrasion was superior for the composites and base alloy although at higher loads adhesion was considered to be main reason for the wear of composites.

A Review on the Fabrication Techniques of Carbon Nanotube Reinforced Aluminium Metal Matrix Composites

Abstract: The recent trend towards the use of composites is increasing in the ongoing research and is likely to continue rapidly in the future. Nowadays, aluminium (Al) and aluminium alloy based composites are gaining importance in the upcoming fields of engineering. Metal matrix composites (MMC`s) with carbon nanotubes (CNTs) reinforcements give superior mechanical and physical properties. Aluminium Metal Matrix Composites (AMMC`s), sought over other conventional materials in the field of automobile, aerospace, defense, sports, electronics, biomedical and other industrial applications, have been becoming essential since the last few years. In the present paper an attempt has been made to review the CNT reinforced AMMC’s fabrication processes through stir casting, compocasting and ultrasonic assisted techniques and discusses the dispersion of CNTs in the matrix. An insight in to mechanical properties of Al-CNTs Metal Matrix Composites is also reported. Keywords: Metal Matrix Composites, Aluminium, Carbon Nanotubes Cite this Article Vijee Kumar, Kempaiah UN, Satish Babu Bopanna et al. A Review on the Fabrication Techniques of Carbon Nanotube Reinforced Aluminium Metal Matrix Composites. Journal of Nanoscience, Nanoengineering and Applications. 2017; 7(2): 1–6p.

Advances in synthesis of graphene derivatives using industrial wastes precursors; prospects and challenges

Abstract: Graphene, a two-dimensional single layered carbon atoms crystal lattice has grabbed much attention due to its unique electronic, surface, mechanical and optoelectronic characteristics. Owing to its unique structure and properties, graphene has opened new opportunities for the future systems and devices, which has led to increase its demand in numerous applications. However, scaling up its production is still a challenging job. Although there is a huge body of literature on the graphene synthesis using various techniques but eco-friendly and cost–effective processes for mass scale production are still needed. In order to conceptualize and develop the processes fulfilling the growing concerns, it is important to overview the existing literature. The current review summarizes the production of graphene using several approaches as well as the potential of various waste materials as graphene precursors. The methods used for graphene synthesis have been categorized into top down techniques such as chemical exfoliation, mechanical exfoliation and chemical fabrication processes, and bottom up techniques including pyrolysis, plasma synthesis, epitaxial growth and chemical vapor deposition (CVD) processes. Conversely, several limitations are considerate for an individual procedure such as toxicity of chemicals, high-cost, time consumption or inadequate quality of the product. Furthermore, mass production of graphene derivatives under low-cost can also be considered by utilizing a variety of wastes precursors such as plastic and batteries waste, newspaper, biomass, chitosan, coal, insects waste etc. This review designates the current advances in wastes-derived graphene synthesis to relief synthetic difficulties as well as predicts the future development in this area.

Advanced production routes for metal matrix composites

Abstract: The use of metal matrix composites (MMCs) in a variety of products is significantly increasing with time due to the fact that their properties can be tailored and designed to suit specific applications. However, the future usage of MMC products is very much dependent on their beneficial aspects and hence it is critical to ensure in a robust repeatable manner the superior physical property advantages compared to conventional unreinforced monolithic metal counterparts. Although numerous routes are available for production of MMC products, each of them has their own advantages and disadvantages. This article provides an overview of advanced production routes for MMCs. The discussion also highlights challenges and presents a future prospectus for MMCs. Powder metallurgy and casting routes are still extensively used for production of MMCs. Aluminum alloys are today the most commonly used matrix materials in MMC products. Carbides (eg, SiC, TiC, and B4C), carbon allotropes (eg, CNTs and graphene), and alumina (Al2O3) are currently the most used reinforcement materials. Nevertheless, the use of nano and of hybrid reinforcements are seeing increased usage in niche applications. Additive manufacturing (AM) is discussed as a novel production route for MMC products. This process represents a promising method for the production of MMC products.

Effect of Hybrid Reinforcements on the Mechanical Properties of Copper Nanocomposites

Abstract: Copper (Cu) composites hybridized with nano-sized reinforcing material are gathering attraction in such fields as automobile, aerospace, and power transmission due to their higher strength. Unlike conventional reinforcing materials, extraordinary mechanical properties and high electrical and thermal conductivity make nanomaterials highly useful reinforcement materials to improve the properties of pristine metals. Over the last two decades, several studies have been conducted to determine the effect of distinctive 2D nanomaterials, such as silicon carbide, aluminium oxide, copper nanotube, and graphene as reinforcement on properties of metal matrices. This study comprehensively reviews the effect of hybrid reinforcements on the mechanical properties of Cu composites having graphene as one of the reinforcements. Also, the contribution of these reinforced nanomaterials composition and their dispersion in the pure Cu matrices have also been explained in detail. In comparison with Cu composites fabricated with a single 2D reinforcement material, composites incorporating hybrid nano reinforcement, exhibit better mechanical behaviour. Additionally, the improvement in mechanical strength would enhance their capability to withstand altering thermal and surrounding environmental conditions.

Development and Mechanical Characterisation of Al6061-Al2O3-Graphene Hybrid Metal Matrix Composites

Abstract: MMC based on aluminium (Al) were produced for light-weight applications especially in aviation and automobile areas. Present paper deals with the fabrication and mechanical performance of AA6061 matrix composites fortified with Al2O3 (alumina) and graphene particulates. Fluid metallurgy method namely stir casting route was employed for fabricating the hybrid composites. Al2O3p and graphene powder are mixed in different weight fractions in which graphene (1 wt. %) particle reinforcement is held consistent and Al2O3 reinforcement is differed freely with 5, 10 and 15 wt. %. Using optical analyser and SEM equipment, microstructural examination is carried out and the result reveals that the graphene and Al2O3 particles prevalently are homogeneously appropriated on the grain limits of Al matrix and Al2O3 particles are disseminated between graphene in the as-cast AA6061 MMC’s. Detailed analysis on investigation of the microstructure and mechanical aspects of Al6061-graphene-Al2O3p composites is presented by following ASTM guidelines; results uncovered that with increment in reinforcement particles, there is an enhancement in the hardness, ultimate strength, yield strength and a decline in the elongation values was however noticed when contrasted with Al6061 alloy. Fractography investigation revealed dimples in unreinforced alloy and the composite.