N. Selvaraj

Preparation of SiC based Aluminium metal matrix nano composites by high intensity ultrasonic cavitation process and evaluation of mechanical and tribological properties

Request augments on a worldwide scale for the new materials. The metal matrix nano composites can be used in numerous applications of helicopter structural parts, gas turbine exit guide vanes, space shuttle, and other structural applications. The key mailman to ameliorate performance of composite matrix in aluminium alloy metal reinforces nano particles in the matrix of alloy uniformly, which ameliorates composite properties without affecting limit of ductility. The ultrasonic assisted stir casting helped agitation was successfully used to fabricate Al 2219 metal matrix of alloy reinforced with (0.5, 1, 1.5 and 2) wt.% of nano silicon carbide (SiC) particles of different sizes 50nm and 150nm. The micrographs of scanning electron microscopy of nano composite were investigated it reveals that the uniform dispersion of nano particles silicon carbide in aluminium alloy 2219 matrix and with the low porosity. How the specific wear rate was vary with increasing weight percentage of nano particles at constant load and speed as shown in results and discussions. And the mechanical properties showed that the ultimate tensile strength and hardness of metal matrix nano composite AA 2219 / nano SiC of 50nm and 150nm lean to augment with increase weight percentage of silicon carbide content in the matrix alloy.

Effect of Elevated Temperatures on the Formability of AA2014 Thin-Walled Tube Ends

Thin-walled tubes are used in a number of industrial applications as interconnecting elements, in the pneumatic, hydraulic, and exhaust systems of machines, in the electrical and electronics industry, as connectors in medical devices etc. The end of the tubes should be formed into different shapes that will suit the need of the above mentioned applications. In most of the applications, the tube ends either will be expanded or converged. However, there is a limit to which these tubes are expanded or converged, which depends on the material property as well as the process used. In the present study, an effort has been made to expand tubes of AA2014 aluminum alloy, which is an aerospace alloy containing copper as one of its main constituent. Different heat treatment processes such as solutionizing, aging, and annealing have been done on the preform to enhance its formability. Due to the low ductility of AA2014 alloy, the tube has been expanded at elevated temperatures. Finite element analysis based simulation studies have been performed to minimize the number of experiments. The formability of the tube has been found to improve considerably at the elevated temperatures.

Characterization of aluminium-red mud-tungsten carbide hybrid metal matrix composite

An environmental hazardous waste material Red mud obtained from Bayers process during the processing of Alumina. Presently it has been difficult for the industries to dispose their wastage and utilization of byproducts. In the current work, Red mud is mixed with other metals mainly aluminium and tungsten carbide to form hybrid metal matrix composites synthesized by powder metallurgy, which has more advanced mechanical properties and applications. Red mud received from the National Aluminium Company Limited (NALCO) has been subjected for sieve analysis and milled to 42 nanometers by using high energy ball mill. Red mud is used as a reinforcement material in Pure Aluminium matrix composite at 2%, 4%, and 6% weight at micro as well as nano levels along with 4%Tungsten carbide by weight is common. Micro and Nano structured red mud powders, Tungsten carbide powder and Pure Aluminium powder is mixed in a V-Blender, compacted at a pressure of 40bar and samples are prepared by conventional sintering. Hardness and wear characteristics are investigated with optimal combination of Aluminium-Tungsten carbide with various weight fractions of micro and nano structured Red mud powder. Energy dispersive X-ray spectroscopy (EDX) and Scanning Electron Microscope (SEM) structures are analyzed to study the particle dispersion.

Dry Sliding Wear behaviour of Aluminium-Red mud- Tungsten Carbide Hybrid metal matrix composites

Red mud is an industrial waste obtained during the processing of alumina by Bayers process. An attempt has been made to utilize the solid waste by using it as the reinforcement material in metal matrix composites. Red mud received from NALCO has been subjected for sieve analysis and milled to 42 nanometers using high energy ball mill. Red mud is used as a reinforcement material in Pure Aluminium matrix composite at 2%, 4%, and 6% weight at 100 microns level as well as 42 nano meters along with 4%Tungsten carbide by weight. Micro and Nano structured red mud powders, Tungsten carbide powder and Aluminium is mixed in a V-Blender, compacted at a pressure of 40 bar and samples are prepared by conventional sintering with vacuum as medium. In this current work, dry sliding wear characteristics at normal and heat treatment conditions are investigated with optimal combination of Aluminium, Tungsten carbide and different weight fractions of micro and nano structured red mud powder.