Applied Mechanics and Materials Vols. 813-814

Abstract: Turning of hardened steel is normally carried out with copious supply of cutting fluid to improve the cutting performance. Most of the cutting fluids in regular use are petroleum based emulsions which create several environmental problems. In this context, pure dry turning is a logical alternative as it is free from the problems associated with the cutting fluid. The achievable tool life and part finish are often affected while machining under completely dry condition. Under such situation, the concept of minimal cutting fluid application (MCFA) presents itself as a possible solution. In this study an effort was made to study the effect of soya bean oil based cutting fluid on cutting performance with minimal cutting fluid application during turning of hardened AISI4340 steel. An 18 run experiment was designed using Taguchi technique to study the effect of fluid application parameters on cutting temperature and surface roughness. Improvement in cutting performance was observed in terms of reduction in cutting temperature and improvement in surface finish (R_a) when water in oil emulsion of soya bean oil was used as the cutting fluid.

Abstract: Drilling is a widely used machining process for various components pertaining to industries such as aerospace, automobile etc. Ti6Al4V is very often used for high stressed components like aircraft structure because of its excellent strength to weight ratio. Tool geometry plays a vital role in effective drilling. It is very difficult to develop a modified geometry in order to achieve better hole quality and improved tool life and validating its outcome experimentally is very expensive. The current paper presents the concept of drilling simulation process using commercial finite element software, Abaqus/Explicit. Five major drill bit geometry such as point angle, helix angle, clearance diameter, and web thickness were varied The proposed simulation model for drilling process was based on Eulierian formulation with explicit interaction. The results of simulation were compared with that of experimental drilling. The simulated result has a good correlation with the experimental result. The change in reference point to chisel tip in the simulation yielded better results as compared to when the reference point is taken at top surface of the tool.

Abstract: Machining hard to machine materials using conventional method of machining has proved to be very costly as these materials greatly affect the tool life because of poor machinability. One material that requires considerable study is Titanium which is a relatively lightweight material and provides excellent mechanical properties. The major problems in machining Titanium Alloys are the high cutting temperatures and rapid tool wear. Machining of Titanium using techniques like Laser Assisted Machining and Plasma Assisted Machining have proven to give high productivity rates, but the costs associated are very high. The main objective of this work is to develop a method for improving the machinability of Ti-6Al-4V using Work Piece Pre-Heating technique by using Conventional Machining with standard tools. Design of experiments was performed using Taguchi’s robust design. The machining operation was performed at elevated temperatures using oxy-acetylene flame. The tools used are Coated and Uncoated Carbide Tools. Based on the tool wear values obtained with different cutting conditions, it is concluded that this technique is feasible with the coated and uncoated carbide tools to machine titanium components commercially.

Abstract: In this article, the effect of wire electrical discharge machining (WEDM) parameters such as pulse-on time (T_ON), pulse-off time (T_OFF), and wire feed (F) on material removal rate (MRR) and surface roughness in metal matrix composites (MMCs) consisting of aluminium alloy (A1356) silicon carbide (SiCp) and Mica is discussed. The Al 356 is reinforced with SiCp and Mica in the form of particulates. The experiments are carried out as per design of experiments approach using L9 orthogonal array. The optimum machining parameters have been identified by a composite desirability value obtained from desirability function analysis as the performance index, and significant contribution of parameters can then be determined by analysis of variance (ANOVA). Confirmation test is also conducted to validate the test result. Experimental results have shown that machining performance can be improved effectively through this approach. The results were analysed using analysis of variance and response graphs. It is found that different combinations of WEDM process parameters are required to achieve higher MRR and minimum surface roughness for composites. These results will be useful for manufacturing engineers to select appropriate WEDM process parameters to machine MMCs of Al 356 reinforced with SiC and Mica.

Abstract: In this investigation, a new approach is based on Grey Relational Analysis and Taguchi method to optimize the machining parameters with multi performance characteristics in WEDM of 304L SS. Experiments are conducted using Taguchi Quality Concept, L₉,3-level orthogonal array was chosen for experiments .The WEDM parameters namely pulse-on time (T_ON), pulse-off time (T_OFF), and wire feed (WF) on material removal rate (MRR) .The Grey Relational Analysis with multiple performance characteristics indicates that the pulse-on time (T_ON), pulse-off time (T_OFF) are the most significant factors . The optimum machining parameters have been identified by Grey relational analysis and significant contribution of parameters can be determined by analysis of variance (ANOVA). The confirmation test is also conducted to validate the test result. The results from this study will be useful for manufacturing engineers to select appropriate WEDM process parameters to machine 304L Stainless Steel.

Abstract: The end milling process is most commonly used where the large amount material can be removed to produce almost final shape of component. The present work deals with the experimental study and optimization the machining parameter of AISI 304 stainless steel. The effects of spindle speed, feed rate and depth of cut have been studied on the cutting force and surface roughness using Taguchi’s 27 orthogonal arrays. Regression analyses were used to develop the model of response parameters. The analysis of the result shows, the surface roughness and the cutting force is increased with feed rate and depth of cut but decreased with increased the cutting speed. The ANOVA indicate the feed rate was the most dominate parameter on surface roughness and cutting force than speed and depth of cut.

Abstract: Electrical Discharge Machining is a thermo-electric process and one of the advanced methods of machining. Most publications on the EDM process are directed towards non-rotational tools, but rotation of the tool provides a good flushing in the machining zone. In this study, the optimal setting of the process parameters on Rotary Electric Discharge machining (REDM) was determined. The important process parameters that have been selected are peak current, pulse on time, pulse off time and rotational speed of tool with output response as Material Removal Rate (MRR).Taguchi experimental design (L27 orthogonal array) was used to formulate the experimental layout and experiments were conducted on Hardened stainless steel machined with copper tungsten electrode. ANOVA method was used with the help of MINITAB 17 software to analysis the influence of input process parameters on the MRR using Rotary Electric Discharge Machining. The input parameters were optimized in order to obtain maximum MRR, The results of the present work revealed that proper selection of input parameters will play a significant role on MRR.

Abstract: This paper embarks the machining parameters of Turning by optimization using Taguchi’s approach. The optimization is very essential in order to obtain the expected surface quality. The results of cutting parameters of optimization is seen in the Surface Roughness, Tool wear and MRR of the material. The L18 Orthogonal array has been chosen for the optimization of Valve Steel SUH03.The uncoated carbide inserts were used and the four parameters Speed, Feed, Depth of Cut and Nose Radius has been taken as input parameters. The Signal to Noise ratio and Analysis of Variance software has been analyzed using Minitab software through which the optimal cutting parameters of the best surface roughness, tool wear and MRR has been obtained. The final results have been compared by the Gray relational analysis to find the optimum machining conditions of all the parameters.

Abstract: Recent developments in the composite materials with high performance increase its range of application most widely but the major disadvantage of these novel materials is machining. The selection of proper process parameters plays an important role in distinguishing machining quality. This work mainly concentrates on the selection of process parameter for minimizing the surface roughness in end milling operation for the newly developed aluminium rock dust metal matrix composite. Taguchi method is used to design and accordingly L27 orthogonal array with five factors viz particle size, weight percentage, cutting speed, feed and depth of cut each at three levels is employed. The experiments were performed in a CNC vertical machining center and corresponding surface roughness values are measured. From the collected data, ANOVA is performed and observations reveal that feed rate influence more on surface roughness followed by particle size, depth of cut, weight percentage and cutting speed.

Abstract: The present research work involves investigating the cylindrical grinding process parameters of Al/SiC metal matrix composites during machining. The effect of grinding process parameters on grinding force, surface roughness and grinding temperature were investigated experimentally using L₂₇ orthogonal array. Grinding process was carried out using different combination of wheel velocity, workpiece velocity, feed rate and depth of cut. The significant grinding process parameters have been determined by using ANOVA. The grey grades identify the optimum level grinding process parameters. From the grey relational grade, low wheel velocity, medium workpiece velocity, medium feed rate and medium depth of cut gives the best results.