Aluminum (Al) Metal Matrix Composites (MMCs) are being used in place of cast iron and steel in automobile, mining and mineral sectors due to their lightweight and high strength. In automobile, aerospace, mining and mineral sectors, there exist situations where two mating parts are in sliding contact with each other. Due to the relative motion, there is an inevitable loss of material. In certain situations, if the extent of material is beyond a critical limit, there are possibilities of catastrophic failure of the components. Wear is a complex phenomenon and the most important reason for the damage and consequent failure of machine parts. This book describes the extensive literature review of the various researchers work on the studies of Al-MMCs. Further, the fabrication of MMCs, of Al6061-SiC, Al6061- Al2O3, Al7075-SiC and Al7075-Al2O3 MMCs. The composites were developed by liquid metallurgy technique via stir casting method which is economical. The fabricated MMCs were subjected to various studies like physical, mechanical and tribological properties along with the OM and SEM studies on the alloys and composites. The obtained results of the MMCs were presented and discussed.
Recently, it has been found that the carbon nanotubes (CNTs) and graphene could prove to be the most promising carbonaceous fillers in polymers nanocomposites field due to their better structural and functional properties. Their uniform dispersion in the polymer matrix leads to significant improvements in their several properties. This book reviews the effect of nanofillers i.e., CNTs, derivatized CNTs and graphene on the electromagnetic interference (EMI) shielding properties of polycarbonate nanocomposite and its application in aerospace, automobile, sports, electronic sectors and various industries. The comparative analysis of carbon-based fillers on the different properties of polycarbonate nanocomposites is also included.
Aluminium alloys are widely used in aerospace and automobile industries due to their low density and good mechanical properties, better corrosion resistance and wear, low thermal coefficient of expansion as compared to conventional metals and alloys. The excellent mechanical properties of these materials and relatively low production cost make them a very attractive candidate for a variety of applications both from scientific and technological viewpoints. This project focuses on the fabrication of Aluminium 7075 matrix composites reinforced with B4C and varying weight % of Al2O3 particulates by Stir casting method. The Microstructure and Mechanical properties of the fabricated Aluminium metal matrix composites are analysed. The SEM images reveal the homogeneous dispersion of Al2O3 and B4C particle in the matrix. The mechanical properties like Hardness and tensile strength have improved with increase in wt % of Al2O3 and B4C particulates in the Aluminium Matrix.
Metal Matrix Composites are engineered materials with a combination of two or more dissimilar materials to obtain enhanced properties. The widespread acceptance of particulate metal matrix composites (MMC) for engineering application has been hindered by the high cost of producing components. Advanced composite materials like metal matrix composite is gradually becoming very important materials in manufacturing industries e.g. aerospace, automotive and automobile industries due to their superior properties such as light weight, low density, high strength and absorb vibrations. In today's life high performance on low cost product is required and well needed. In this present investigation Al (6061) alloy has been used as a matrix material and agro waste rice husk ash (RHA) as an reinforcement to form a composite by using two step stir casting process. RHA has been used because it is the only agro waste which contains the maximum amount of silica. Since RHA is obtained as a byproduct solid waste during milling of rice it is completely free of cost and available in abundance. To assess the performance of the composites the mechanical properties, microstructural analysis were used.
The problem of scheduling n jobs each of which must be processed by m machines with shop dependent processing order is examined. If the order in which a given job is processed on the machine is not fixed, the system is called an open shop. This situation might occur in testing components of an automobile. The computational difficulty of solving most open shop problem is known with the majority being NP- hard. In shop scheduling problem, a combination of machine order and job order is represented by a shop graph or by the corresponding rank matrix pair (MO, JO). A task is to determine an optimal feasible sequence. Various models of mathematics have been presented to solve different shop scheduling problems. Here, the disjunctive graph model, block matrices model without preemption and with preemption and linear programming models are studied. Some problems have also been represented by Gantt charts. Polynomial time algorithms have been presented with complexity analysis. Some NP- hard problems are also discussed in both cases with preemption and without preemption.
Aluminum alloy based metal matrix composites MMC) are gaining importance in several aerospace and automobile applications. Aluminum has been used as matrix material owing to its excellent mechanical properties coupled with good formability. Addition of SiC as reinforcement in aluminium system improves mechanical properties of the composite. In the present investigation, Al-SiC composite was prepared by powder metallurgy route. Powder metallurgy homogeneously distributes the reinforcement in the matrix with no interfacial chemical reaction and high localized residual porosity. SiC particles containing different weight fractions (10 and 15 wt %) and mesh size (300 and 400) is used as reinforcement .Though AlSiC possess superior mechanical properties, the high abrasiveness of the SiC particles hinders its machining process and thus by limiting its effective use in wide areas. Rapid tool wear with poor performance even with advanced expensive tools categories it as a difficult-to-cut material. Nonconventional processes such as electrical discharge machining (EDM) could be one of the best suited method to machine such composites.
Modern trend is to prepare hybrid materials using nanoclays. Formation of nanoclay, exfoliated clay, proper dispersion in polymer matrix still remains a challenge. There are three specific problems to be dealt with at present. Aspect ratio of the clay particles must be very thin in cross section, present a large surface area in its flat dimension, serves the purpose of maximizing gas permeability. Clay particles that grow on aggregates must be broken down or exfoliated into individual sheets that have thickness of 1 nm. Particles must be compatible with the polymeric substrate. The objective of this work is to disperse clay using various dispersants using natural ones. The green hybrid material so formed by clay polymer matrix has many improved properties such as high Tg, high flame resistance, high tensile strength and improved barrier properties which may find application in textile industry, automobile industry, environmental and polymer engineering fields.
Aluminum Metal Matrix Composites (AMMCs) are the well defined materials for marine, automobile, aerospace, defense, and sports industries, as they have high strength to weight ratio, and possess superior physical and mechanical properties compared to UN-reinforced alloys and traditional metals. However, the presence of abrasive reinforcements in the ductile matrix causes rapid tool wear and hence tool failure. This leads to an increase in machining cost, production time and poor quality of machined components. Among all traditional machining processes, drilling is one of the most important metal-cutting operations, comprising approximately 33% of all metal-cutting operations. Drilling processes are widely used in the aerospace, aircraft and automotive industries. Although modern metal-cutting methods have been improved in the manufacturing industry, including Electric Discharge Machining, Ultrasonic Machining, Electro Chemical Machining, Laser Beam Machining and Abrasive Jet Machining, conventional drilling still remains one of the most important machining processes. Among the cutting conditions which influence the drilling process, coolant is an important factor largely affects
In today s world low weight and high efficiency with no compromise to mechanical properties is the main area of attention of researcher s. In this arena design of composite materials is emerging as the challenging field of research. With the design of Metal Matrix Composites (MMC s) one can achieve tailor made properties, which otherwise are impossible to achieve out of single material. In this book, liquid metallurgy technique has been suggested to develop Aluminum-Silicon Carbide (Al-SiC) Metal Matrix Composite (MMC s). Then emphasis has been made to characterize the tribological properties of the MMC s with its focused application in the automobile sector.