Materials Science Forum Vol. 969

Abstract: In recent years, the continuous growth in manufacturing industries such as light weight structures, demands in increasing of its performance and functionality enhance the use of different materials for producing hybrid structures and thus the requirements for joining of dissimilar joints. The physical and metallurgical properties of the materials are utilised to get combined properties to achieve the product performance. On the other hand the joining methods are continuously challenging for joining of dissimilar materials. The present study reviews and describes the effective welding method of cold metal transfer for joining of dissimilar materials and its state of the art research in various materials joining. Cold metal transfer joining mechanism, capabilities of joining of dissimilar metals and their performance are reviewed. The current and emerging techniques of cold metal transfer welding method are reviewed. Methods and other technological parameters selection are described and future challenges for improving research methods on joining of dissimilar metals using cold metal transfer. Keywords: Cold Metal Transfer, MIG welding, Dissimilar materials, Mechanical properties.

Abstract: Friction surfacing is a solid-state coating technique process in which a mechtrode is rotated against the substrate under pressure, henceforth forming a coat on the substrate. This process not only can be used as coating process but it also provides flexibility in coating different materials as a revamp manufacturing process and it is suitable for getting excellent mechanical properties after the surfaced deposits. Bond strength is very good and these deposits are expected to serve better service life. The present work deals with mechtrode of SS-316, D3-tool steel and aa-2014 are coated on low carbon steel substrate by friction surfacing process and design of experiment were done by using taguchi L9 orthogonal array where the process parameters are mechtrode, rotational speed and traverse speed. The coating thickness, coating width and the SEM-microstructure analysis were studied.

Abstract: Contaminated land is a legacy of industrial revolution as a result of rapid growth of industries. Since long back, the disposal of liquid and solid wastes on land though undesirable, has been in practice. The leachate generated out from these hazardous wastes infiltrates into the ground and causes multiple problems viz., ground water pollution, soil pollution, loss of nutrition value of soil and thereby severe damage to plantation growth, changes in the soil behavior (excessive swell/shrink) depending on the nature of waste. It also causes serious distress to the existing structures such as pavements, foundations, underground pipelines and culverts. The changes in the soil behaviour caused by ground contamination can lead to structural failures. The present paper describes various physical, chemical, biological, thermal and solidification/stabilization methods of soil and ground water remediation and their comparison on the basis of applicability, time and cost.

Abstract: In recent years, there is a lot of demand on metal forming processes in which sheet metal forming process has lots of applications in the automotive and aerospace industries. In sheet metal forming operations, incremental forming is an emerging technology in which, single point incremental forming (SPIF) process is die-less in incremental forming process and providing a competitive alternative to economical and effective in fabricating low volume products. The objective of this work is to analyze the forming analysis on truncated pyramid product by avoiding cracking and maintaining the optimum forming conditions. The formability is analyzed by using ABAQUS software and simulation, different process parameters were varied such as sheet thickness, tool diameter, step depth, spindle rotational speed on aluminum AA1050 alloy. From the simulation results, stress stain and stain distribution were evaluated on the deformed sheet. The product produced is truncated pyramid dimension having square base of side and fillet at corner.

Abstract: This work, Seamless Austenitic 213 tube is welded with Seamless Austenitic 387 tube plate through friction welding of tube to tube plate using an external tool (FWTPET) method in presence of backing block by using clearance fit method. Further, the analysis of microstructural features on the interface of weld exhibit that the FWTPET is able to generate flawless welds. In all nine various work specimen which welded under the various circumstances, the hardness value, tensile strength have taken. In this work, two type of specimen has taken where one kind is the tube which contains no hole and another one is with the hole in the circumference. 806.28 MPa and 746.5 MPa were the optimum strength for the workpiece which is not a having a hole and having the hole on the circumference.

Abstract: Electric Discharge Machining (EDM) is used to machine complex geometries of difficult to cut materials in the area of making dies, mould and tools. Currently, hydrocarbon based dielectric fluids are used in EDM and which plays major role for material removal and it emits harmful emission. In this work, vegetable oil is attempted as dielectric fluid and their performance are studied during processing of AISI P20 steel. The effect of pulse on time (P_on) , pulse off time (P_off), and current (A) on Material Removal Rate (MRR), Tool wear rate (TWR) and surface roughness (SR) are analyzed. The result showed that vegetable oils are given good machining performance than conventional dielectric fluids. These proposed dielectric fluids are biodegradable eco friendly and enhance sustainability in EDM process.

Abstract: The main aim of the present topic is friction stir welding (FSW) of Aluminium HE-30, which shows that improved microstructures, strong weld and with less of defects. In the other hand, an attempt was made to correlate the welding parameters and mechanical properties. In the present investigation four rotational speeds of 1000 rpm, 1200 rpm, 1400 rpm and 1600 rpm with travelling speed of 30 mm/min. and tool geometry (straight cylindrical) was chosen. It was observed that the tool rotational speed is a sensitive parameter to decide the ultimate tensile strength and yield strength of the present material. Similarly, the hardness of Al plates is improved at the weld zone. Hence, it is suggested that to consider a parameter such as welding tool rotational speed, travelling speed and materials in selecting the welding methods of sound joints, because it influences the microstructure and mechanical properties in various applications. In the present study, non-destructive tests are also confirmed the defective nature of the weld zone of Al plates.

Abstract: Aluminum metal matrix with carbon fibre reinforcement composites are potential materials for automotive, aerospace and electronics industries. The interaction between Al matrix and carbon fibre reinforcement, plays vibrant role to decide the properties of the Metal Matrix Composites (MMC’s). However, interaction between Al alloy matrix and carbon fibre is forming an Aluminum Carbide (Al4C3) at higher temperature (>650°C). This consequence degrades the mechanical properties and promotes corrosion. To overcome corrosion problem and improve the composite properties, metallic coating on carbon rod is very vital. In the present study, aluminum metal matrix composites (Al6082/4%Al₂O₃+2%Gr) were developed with coated carbon fibre rod using stir casting process. Carbon fibre rods of 3 mm diameter is coated with nickel by electro less process and then copper coating done by electrolytic process. The bonding between matrix and reinforcement was observed in SEM and EDAX analysis. The results indicates the absent of Al₄C₃ formation.

Abstract: Turning of hardened alloy steel (Hard turning) is a replacement for grinding operation. The heat generation and temperature during hard turning at the cutting zone and due to the friction at tool-chip-workpiece interface are significant parameters which influence chip formation mechanism, tool wear, tool life, surface integrity and hence the machining quality. Cutting fluid performs key role in metal cutting due to its cooling and lubrication action. Flood cooling is a common method of cutting fluid application, in which large quantity of cutting fluid is applied at the cutting zone. Due to environmental, health and safety concerns, the usage of cutting fluid in abundant quantity is being restricted. Most of the researchers have varied the cutting parameters like cutting speed, feed rate and depth of cut to machine different work materials with different cutting tools and studied its effects on cutting force and cutting temperature. It is thus essential to study the combine effect of cutting and jet parameters in machining. This research article focusses on study and optimization of cutting and jet parameters on tool-chip interface temperature and cutting forces during turning hardened alloy steel AISI 4140 steel of 50 HRC using Finite Element Analysis and Taguchi’s Technique. Three levels of cutting speed, feed rate, depth of cut, jet angle and jet velocity are chosen. A suitable L27 Orthogonal array is selected based on Taguchi’s Design of Experiments (DoE) and the output quality characteristics such as tool-chip interface temperature and cutting forces are analyzed by Signal-to-Noise (S/N) ratio. Analysis of Variance is performed to determine the most contributing factor, which shows that the feed and depth of cut are the most prominent contributing parameter followed by cutting speed, jet impingement angle and jet velocity.

Abstract: Enormous research work has done on the electrode wear in spark erosion machining such as hybrid electrical discharge machining process, introducing various methods such as ultrasonic vibration in electrode, rotating the electrode, developing new electrode material (alloys and composites) and surface coated electrode etc,. Equal Channel Angular pressing is one such technique which makes tool material harder through grain refinement and ultimately enhances the tool life. The work material is AISI H13. For this research work, two copper electrodes are prepared, out of which one copper electrode has undergone equal channel angular pressing process. The most influencing parameters of spark machining like current, pulse on time and pulses off time are chosen for this study. The experiments are conducted using bare copper electrode and equal channel angular pressed copper electrode based on the box Behnken approach. The observations are analyzed for the machining characteristics in terms of rate of machining, rate of tool erosion and surface coarseness. Finally, it is found that ECAP processed copper electrode has lesser wear rate and better surface finish than bare copper electrode.