Experimental Investigation of Process Parameters in Electrochemical Machining

Electrochemical machining is a non-conventional machining process worked with a principle of Faraday’s law. It is one of the best alternatives for producing complex shapes in advanced materials used in aircraft and aerospace industries. However, the reduction of the stray material removal continues to be a major challenge for industries in addressing accuracy and improvement. It is very difficult to appliance a high strength, heat-resistant material into complex shapes by conservative techniques, but such materials can be effectively machined by electrochemical machining (ECM) method. This experiment highlights features of the development of a comprehensive mathematical model for correlating the interactive and higher-order influences of various machining parameters on the dominant machining criteria, i.e. the metal removal rate and the surface roughness phenomena, through Taguchi method and RSM method using the pertinent experimental data as obtained by experiment

Multi-Objective Optimization of Wire Electro Discharge Machining (WEDM) Process Parameters Using Grey-Fuzzy Approach

Wire electro discharge machining (WEDM) is a versatile non-traditional machining process that is extensively in use to machine the components having intricate profiles and shapes. In WEDM, it is very important to select the optimal process parameters so as to enhance the machine performance. This paper emphasizes the selection of optimal parametric combination of WEDM process while machining on EN31 steel, using grey-fuzzy logic technique. Process parameters such as servo voltage, wire tension, pulse-on-time and pulse-off-time were considered while taking into account several multi-responses such as material removal rate (MRR) and surface roughness (SR). It was found that pulse-on-time of 115 µs, pulse-off-time of 35 µs, servo voltage of 40 V and wire tension of 5 kgf results in a larger value of grey fuzzy reasoning grade (GFRG) which tends to maximize MRR and improve SR. Finally, analysis of variance (ANOVA) is applied to check the influence of each process parameters in the estimation of GFRG

Mission oriented R and D and the advancement of technology: The impact of NASA contributions, volume 2

NASA contributions to the advancement of major developments in twelve selected fields of technology are presented. The twelve fields of technology discussed are: (1) cryogenics, (2) electrochemical energy conversion and storage, (3) high-temperature ceramics, (4) high-temperature metals (5) integrated circuits, (6) internal gas dynamics (7) materials machining and forming, (8) materials joining, (9) microwave systems, (10) nondestructive testing, (11) simulation, and (12) telemetry. These field were selected on the basis of both NASA and nonaerospace interest and activity

Design of lightweigh electric vehicles

The design and manufacture of lightweight electric vehicles is becoming increasingly important with the rising cost of petrol, and the effects emissions from petrol powered vehicles are having on our environment. The University of Waikato and HybridAuto's Ultracommuter electric vehicle was designed, manufactured, and tested. The vehicle has been driven over 1800km with only a small reliability issue, indicating that the Ultracommuter was well designed and could potentially be manufactured as a solution to ongoing transportation issues. The use of titanium aluminide components in the automotive industry was researched. While it only has half the density of alloy steel, titanium aluminides have the same strength and stiffness as steel, along with good corrosion resistance, making them suitable as a lightweight replacement for steel components. Automotive applications identified that could benefit from the use of TiAl include brake callipers, brake rotors and electric motor components

Modeling and Optimization of Micro-EDM Operation for Fabrication of Micro Holes

Based on the experimental results, an analysis was made to identify the performance of various electrodes during fabrication of micro holes considering Inconel 718 as well as titanium as workpiece materials. It was found that that platinum followed by graphite and copper as electrode material exhibited higher MRR for both the workpiece materials but on the other hand platinum showed higher values of OC, RCL and TA respectively when compared to graphite and copper. The variation of temperature distribution in radial and depth direction with different process parameters has been determined for Inconel 718 and Titanium 5. Theoretical cavity volume was calculated for different process parameter settings for both workpiece materials and it was found that Titanium 5 exhibited higher cavity volume then Inconel 718. This research work offers new insights into the performance of micro-µ-EDM of Inconel 718 and Titanium5 using different electrodes. The optimum process parameters have been identified to determine multi-objective machinability criteria such as MRR, angle of taper of micro-hole, the thickness of recast-layer and overcut for fabrication of micro-holes

Tool Wear Characterisation and Parameter Optimisation in Micro-manufacturing Processes

Increases in demand for miniaturised static parts, actuators and devices has presented challenges in machining; requiring fast advancement in the field. This work examines two processes: Wire Electrical Discharge Machining (WEDM), and micro-milling. While very different processes, both of these have in common the fact that their behaviour and the phenomena seen differ from those seen in conventional subtractive machining. Capability of machine tools has increased to allow highly intricate parts to be produced, but there are significant challenges in achieving excellent surface finish, geometrical accuracy and tool life. WEDM is appropriate for cutting complex shapes without long set-up times, but cutting very thin workpieces represents difficulties in achieving stable machining, while the process results in a recast layer which can affect wear and transmission. This work focuses on investigating optimal parameters for machining micro-gears. This has traditionally been challenging because the limited area for spark generation between wire and workpiece leads to unstable machining, resulting in poor machining rate and surface finish. Investigations into significant machining parameters have taken place, followed by a feasibility study cutting brass gears of 0.3 mm thickness. The results indicate that the depth of the recast layer can be minimised while maintaining an acceptable Material Removal Rate (MRR), by considering gear geometry. This work suggests that WEDM is a valuable tool in prototyping miniature gears. Micro-milling allows small, accurate parts to be produced, but micro-tools wear quickly and unpredictably, therefore tool wear is difficult to measure. This results in a high rate of tool changes and reduced productivity. A protocol for measuring tool wear has been produced to allow a common method to be used across research institutes. This presents a method for analysing and reporting micro-mill tool wear which will allow transfer between research institutions and industry, to extend tool life and improving process efficiency. This protocol has then been used to investigate tool coatings on the micro scale, and compare the tribological processes seen on micro-tools to their macro counterparts. This work has resulted in extended tool life for industrial micro-mills and has been applied to industrial situations

Energy Materials Coordinating Committee (EMaCC): Fiscal year 1996. Annual technical report

The DOE Energy Materials Coordinating Committee (EMaCC) serves primarily to enhance coordination among the Department`s materials programs and to further effective use of materials expertise within the Department. These functions are accomplished through the exchange of budgetary and planning information among program managers and through technical meetings/workshops on selected topics involving both DOE and major contractors. In addition, EMaCC assists in obtaining materials-related inputs for both intra- and interagency compilations. The EMaCC reports to the Director of the Office of Energy Research in his or her capacity as overseer of the technical programs of the Department. This annual technical report is mandated by the EMaCC terms of reference. This report summarizes EMaCC activities for FY 1996 and describes the materials research programs of various offices and divisions within the Department

Advanced Industrial Materials (AIM) Program: Annual progress report FY 1995

In many ways, the Advanced Industrial Materials (AIM) Program underwent a major transformation in Fiscal Year 1995 and these changes have continued to the present. When the Program was established in 1990 as the Advanced Industrial Concepts (AIC) Materials Program, the mission was to conduct applied research and development to bring materials and processing technologies from the knowledge derived from basic research to the maturity required for the end use sectors for commercialization. In 1995, the Office of Industrial Technologies (OIT) made radical changes in structure and procedures. All technology development was directed toward the seven ``Vision Industries`` that use about 80% of industrial energy and generated about 90% of industrial wastes. The mission of AIM has, therefore, changed to ``Support development and commercialization of new or improved materials to improve productivity, product quality, and energy efficiency in the major process industries.`` Though AIM remains essentially a National Laboratory Program, it is essential that each project have industrial partners, including suppliers to, and customers of, the seven industries. Now, well into FY 1996, the transition is nearly complete and the AIM Program remains reasonably healthy and productive, thanks to the superb investigators and Laboratory Program Managers. This Annual Report for FY 1995 contains the technical details of some very remarkable work by the best materials scientists and engineers in the world. Areas covered here are: advanced metals and composites; advanced ceramics and composites; polymers and biobased materials; and new materials and processes