Papers by Keyword: Electrochemical Machining

Abstract: Additively manufactured Nitinol components often exhibit rough surfaces and defects that affect functional performance. This study investigates the feasibility of electropolishing Nitinol in a deep eutectic solvent (ethaline). Linear sweep voltammetry was used to identify anodic potentials suitable for controlled dissolution, and electropolishing was performed at selected potentials. Surface evolution was analysed by SEM, EDX, optical microscopy, and confocal microscopy. Electropolishing in ethaline effectively reduced surface scratches and produced more homogeneous surfaces without altering alloy composition. Higher applied potentials (12.5 V) resulted in complete removal of surface scratches and visually homogeneous surfaces, whereas lower potentials (6 V) mainly reduced the visibility of surface scratches. Compared to conventional inorganic electrolytes, the process exhibits a lower dissolution rate, offering a safer and more controllable approach.

Abstract: Electrochemical Machining (ECM) is a modern metal working process that make it possible to machine products that are challenging or even impossible to create using traditional machining methods. This study aims to explore how surface roughness and machining rate in ECM are influenced by magnetic field on the metal matrix composite with different machining process input. Neodymium magnets were employed to generate the magnetic field during experiments. The workpiece material used in this experiment is aluminum 6061 alloy, Al-B4C, Al-SiC and the tool material is copper. The input parameter used in this experiment was varying such as electrolyte concentration, voltage, gap, and type of material. Minitab software was used to analyze the results and orthogonal arrays are used in the Taguchi design of the experiment. The results showed that in all experiments, the magneto hydrodynamic effect both reduces surface roughness and increases the machining rate. Furthermore, the Al6061 alloy exhibited the smoothest surface finish and the highest machining rate.

Abstract: This paper demonstrates that 18 μm deep surface understating with a tolerance of 4.5 μm and a roughness Ra=0.4 μm can be produced to the required accuracy by electrochemical die-sinking if configured appropriately.Theoretical analysis shows that the bottom profile error can be presented as a superposition of the errors of surface alignment (non-parallel bottom) and shape (non-flat bottom). In this case, the alignment error accounts for a greater part of the size tolerance (3 μm out of 4.5 μm). This is why the attainment of desired accuracy revolves around the development, analysis, and assessment of ways to reduce this error.

Abstract: This study investigates the possibility of electrochemical removal of the defective layer formed on the surface of the product after its electrical discharge machining. A set of experiments was conducted in different electrolytes based on aqueous and aqueous-organic solvents. The experiments were to trace the influence of such settings of electrochemical machining as current density, electrolyte pumping speed, electrolyte temperature, and an electrode gap upon both the dynamics of metal removal and surface quality. Morphology of the obtained surface was examined by an Olympus BX-51Microscope. The dynamics of removing material (stock) from the work piece was inspected. Appropriate adjustments were made to the machining parameters during the machining of 65G steels, and a preferred composition was selected for the working medium. A sufficient design for production tools was proposed. Pitting corrosion was discovered on the surface of the samples in all studied modes of electrolysis. It was observed that switching from aqueous electrolyte to aqueous-organic electrolyte gave lower material removal rate and longer machining time accordingly. At the same time, a reduction in surface roughness was visualized, together with smaller pits and lower density of their distribution. The obtained results may be applied in operation design for electrochemical machining of steels with relatively high carbon contents.

Abstract: Nitinol consists of nickel and titanium. Nitinol is one of the shape memory alloys, which changes the crystal structure at a certain temperature and is restored to a memorized form. Because of these unique features, it is used in medical devices, high precision sensors, and aerospace industries. However, Nitinol is a traditional method of processing, resulting in thermal deformation and residual stress after processing. Therefore, the electrochemical machining (ECM), which does not produce residual stress and thermal deformation, has emerged as an alternative processing technique. This study used artificial neural network (ANN), which are the basis of AI, to replace conventional design of experiments (DOE). This method was shown to be more useful than conventional method of design of experiments (RSM, Taguchi) by applying artificial neural network to electrochamical machining (ECM) and comparing root mean square errors (RMSE).

Abstract: Electrochemical machining process is an advanced material removal technique offering high precision and introducing no heat damage to the work material. The shape and size of machined area are highly dependent on some process parameters such as voltage, electrolyte and inter-electrode gap. To further enable a more insight into the process performance, this paper investigates the influences of applied voltage, electrolyte concentration and inter-electrode gap on the shape and sizes of hole produced by the electrochemical drilling process. Titanium alloy (Ti-6Al-4V) was used as a work sample in this study as it has been extensively used in many advanced applications. The experimental result indicated that the use of high voltage and high electrolyte concentration can enlarge and deepen hole in the workpiece, while the inter-electrode gap provided less effect to the hole features. The maximum hole depth can reach 300 μm within 60 seconds when the applied voltage of 30 V, the inter-electrode gap of 10 μm and the electrolyte concentration of 10%wt were used. However, with this setup, the obtained cut profile became a non-uniform V-shaped hole. The use of lower voltage was instead recommended to yield a better cut quality with U-shaped profile.

Abstract: Utilizing all-direction electrochemical machining (ECM) for super-thin twist aero-engine, feed angle of tool cathode and blade fixture angle are investigated and optimized in this study. The most optimal combination of the two angles (oblique feed angle of tool cathode and fixture angle of blade stock) is selected from all 65341 angle combinations. Moreover, the affections of the optimized angle combination on machining error distribution between blade shape and plate are concentrated. The analysis and experimental results demonstrate that the optimized angle combination can satisfy the machining requirements of blade shape and error distribution of blade shape and plate.

Abstract: In order to fabricate the micro cavity with complex structure on stainless steel, the technology of micro electrochemical machining based on surface modification by fiber laser is adopted. Heating scan on the surface of 304 stainless steel by using fiber laser can realize marking. In the process of laser heating and metal melting on the surface of 304 stainless steel, oxide layer can be formed and phase transformation can also occur, and the corrosion resistance layer with predefined pattern is formed. In the next process of micro electrochemical machining, the laser masking layer severs as the protective layer to realize micro machining of micro cavity. A newly developed device of electrochemical micro machining based on surface modification by fiber laser can meet the micro machining requirement. After laser masking processing through laser scanning on the surface of the 304 stainless steel, the passivation electrolyte and high-frequence-pulse electrochemical machining power supply were adopted, and the samples with typical structures by using electrochemical micromachining with fiber laser masking were fabricated.

Abstract: The electrochemical machining method ensures conditions for machining workpieces made of electroconductive materials, when the classical machining methods could not be applied or when their use is not able to offer a high efficiency of the machining process. The large diversity of the electrochemical machining procedures needs information about the specific work conditions and adequate establishing of the parameters which characterize the machining process and the factors able to exert influence on the parameters of technological interest. In order to design and materialize some electrochemical machining procedures, an analysis of the conditions specific to the work zone and of distinct subsystems specific to electrochemical equipment was developed. Taking into consideration the results of analysis, equipment for electrochemical machining was designed and materialized. One considered also some possibilities to develop subsequently scientific researches concerning aspects specific to the electrochemical machining process. Preliminary tests proved the possibilities of using the equipment and of its improving in the future.

Abstract: Aluminium reinforced with SiC, Al₂O₃ and B₄C etc. possesses an attractive combination of properties such as high wear resistance, high strength to weight ratio and high specific stiffness. Among the various reinforced materials used for aluminium, B₄C has outperformed all others in terms of hardening effect. Particle size reduction of B₄C is found to have positive impact on the material hardness. In the view of physical properties, B₄C has less density than that of SiC and Al₂O₃, which makes it an attractive reinforcement for aluminium and its alloys for light weight applications. In this work, Al nano B₄C composite prepared by ultrasonic cavitation method was machined by Abrasive assisted electrochemical machining using cylindrical copper tool electrodes with SiC abrasive medium. In this paper, attempts have been made to model and optimize process parameters in Abrasive assisted Electro-Chemical Machining of Aluminium-Boron carbide nano composite. Optimization of process parameters is based on the statistical techniques using Response Surface Methodology with four independent input parameters such as voltage, current, abrasive concentration and feed rate were used to assess the process performance in terms of material removal rate and surface finish. The obtained results were compared with abrasive assisted electro chemical machining of Aluminium-Boron carbide micro composite and the effect of particle size on the process parameters was analyzed.