Applied Mechanics and Materials Vols. 592-594

Abstract: The aim of this project is to study the micro-structural and mechanical property changes during friction stir welding [FSW] with a special focus on AA5052. The objective of this project is to experimentally investigate the influence of tool pin profiles (straight cylinder, fluted cylinder and pentagonal cylinders) and welding input parameters (rotational speed and traverse speed) on microstructure and mechanical properties (tensile strength, hardness) of AA5052 Al in FSW process. The detailed micro-structural analyses are carried out on the base metal and welded zone (nugget zone), Thermo mechanically affected zone and heat affected zone. The mechanical properties such as, tensile and hardness are studied before and after FSW process.

Abstract: Surface refining of Al–Si alloy was carried out using the GTA heat source. It was observed that the microstructure contains a globular shaped eutectic – Si distribution within the α–Al matrix. The hardness is found to increase and the wear is found to decrease upon surface refining. The precipitation hardening treatment was effective in increasing the hardness of the modified layer. The GTA heat source has been successfully applied to the surface refining of the Al–Si alloy. The result of this study is comparable to those of previous studies.

Abstract: An investigation was carried out to understand the effect of process variables on the microstructure, hardness and wear properties of surface modified Cu-10Sn bronze alloy. The surface modification was carried out using Gas Tungsten Arc (GTA) as the heat source. Hardness and wear rate of the modified layer were measured using a microhardness tester and a Pin-On-Disc wear tester, respectively. A uniformly distributed fine grained microstructure was observed in the modified layer. The hardness and wear resistance of the modified layer were improved when compared with that of as cast sample. The coefficient of friction is found to be a constant and is not a function of hardness. The results of this study are comparable to those of previous works.

Abstract: In this work we have satisfied the objective to analyse the medium carbon steel rods which are welded frictionally on their tensile properties when the welding parameter is maximum and minimum in values of forging pressure with respect to time. This work also carries the macrostructure and microstructure analysis of the weldments so as to identify the metal flow and grain structures in different zones of the welds. This work is carried to identify the suitable level of value of the forging pressure with respect to time and analysing their mechanical properties in that level. Fracture analysis was also carried out in the fracture surface.

Abstract: In recent year’s Natural Fibers reinforced composite (NFRC) are considered as a suitable alternative to engineering material due to their advantages like low cost, low density, high strength and stiffness to weight ratio, resistance to breakage during processing, low energy consumption, a lesser amount of pollutant emissions and biodegradable materials. They have excellent properties and are being extensively used in verity of engineering application like aircraft and aerospace etc.This paper examines the mechanical properties of Zea Mays Straw powder (ZMSp) particles reinforced polyester composites with the aim of producing a composite material showing enhanced properties for engineering applications. Zea mays straw particles were added in different volume fractions into polyester matrix at 5, 10 and 15 gram respectively. Composite samples were produced from these mixtures and the effect of the tensile properties of the composites was investigated. The tensile strength, tensile modulus values increases as the zea mays straw powder. Among the three samples the 15gram added Zea mays composite bar gives better tensile modulus and strength than the other two samples.

Abstract: The main aim of present research paper is to analyze the influence of compaction load and sintering temperature on relative density of low carbon alloy steel. The alloy steel powder has been compacted at different loads and sintering at different temperatures. The compaction of alloy steel has been done with a circular die of 20 mm internal diameter and 100 mm height at different load and sintering temperature. With the application of hydrostatic stress, the pores will be removed and relative density will increase. So, relative density value will increase simultaneously. This experimental study presents how relative density can be improved by using Powder Metallurgy route. The results are further analyzed with the help of Analysis of Variance using Design of Experiments Tool.

Abstract: Close tolerance and precision requirements of biomedical components and miniaturization of sensors has given micro wire electrical discharge machining (μWEDM) a substantial amount of research attention. The process parameters like gap voltage, capacitance, wire feed rate and wire tension play an important role in influencing the quality characteristics of the machined parts. The challenge lies in selecting the optimal machining parameter combination to achieve the desired surface finish and metal removal rate in a multi input multi output process like μWEDM. The process parameters were varied at three levels and Taguchi’s L₉ orthogonal array was used to design and conduct the experiments. Desirability analysis was applied for predicting the optimal setting of machining parameters and ANOVA results had revealed the significant role of wire feed rate and gap voltage in affecting the quality characteristics of the process

Abstract: The number of gas molecules and the volume of the vessel are used as independent arguments in the equation of state. It allows one to use this description in difficult conditions when variability in the number of moles of the structural elements and in the molar volume plays an appreciable role. Application of the kinetic model of the processes in multicomponent mixtures allowed one to determine the area of macroparameters, where mesoscopic properties of large clusters appear in thermal diffusion: thermal diffusion coefficient for them corresponds to liquids.

Abstract: In this study, an attempt has been made to develop solid lubricant cutting tool material with the aid of powder metallurgy technique. Chosen tungsten carbide, cobalt and calcium fluoride were milled in the planetary ball milling, followed by uniaxial compaction and sintering in a tube furnace. Materials were milled at various hours of milling and compaction pressure to understand the effect of relative density and hardness of sintered specimens. It is found that the relative density of compacted and sintered specimens found to increase with the compaction pressure but decreased with milling time after particular time. From the investigation, 40 hr of milling and 400 MPa compaction pressure found to be suitable for the development of proposed material. In this work, sample density was measured by the Archimedes’ method and hardness was measured by Rockwell hardness tester.

Abstract: The aim of present experimental investigation is to compare the mechanical properties of Sisal, jute and kenaf fiber reinforced with glass fiber in polyester matrix hybrid composites. Hybrid composites were fabricated by hand lay-up technique. The tensile, flexural and impact tests were carried out on different composite samples as per the ASTM standards. It was observed that the tensile strength of jute/glass fiber composite is 1.94 and 1.59 times more than that of sisal/glass and kenaf/glass composites, respectively. The flexural load carrying capacity of sisal/glass composite is 3.4 and 2.83 times greater than those of jute/glass and kenaf/glass composites, respectively. Also, it can be seen that impact strength of jute/glass composite is almost equal to that of kenaf/glass composite and 1.13 times more than that of sisal/glass composite.