Enhanced Micro-Electric Discharge Machining-Induced Surface Modification on Biomedical Ti-6Al-4V alloy

In the midst of a huge demand for high-precision miniaturized medical implants made up of potential biomaterials, the biomedical Ti-6Al-4V alloy meets the uncompromising standards for longevity, biocompatibility, and sterilizability required to interact with living cells in medical settings. This research tailored the existing capabilities of a traditional micro-electric discharge machining (μ-EDM) setup by adding 0, 2, 4, 6, 8, and 10 g/l bioactive zinc powder-particle-concentrations (PPCs) to the dielectric. A copper and brass micro-tool electrode (C-μ-TE and B-μ-TE) were employed in association with each PPC, and experiments were executed using one-variable-at-a-time (OVAT) approach. Machining time and dimensional deviation were chosen as the response variables of Zn powder mixed-micro-EDM (Zn-PM-μ-EDM). According to the analytical findings, the combination of C-μ-TE and 6 g/l Zn PPC achieved 23.52 %, 3.29 %, and 17.96 % lesser machining time, dimensional deviation, and recast layer thickness, respectively, compared to the B-μ-TE. The detailed study of this surface endorsed a significant modification in terms of improved recast layer thickness (26.44 μm), topography (Ra = 743.65 nm), and wettability (contact angle < 90°), suggesting its dental application. Additionally, the observation of ZnO and TiO in X-ray diffraction and appealing in vitro cytocompatibility encourage the subsequent biological and therapeutic studies to validate the anticipated anti-viral activity of the modified Ti-6Al-4V alloy surface against coronavirus (COVID-19).

Micro-Milling Process of Metals: A Comparison between Femtosecond Laser and EDM Techniques

Nowadays, micro-machining techniques are commonly used in several industrial fields, such as automotive, aerospace and medical. Different technologies are available, and the choice must be made considering many factors, such as the type of machining, the number of lots and the required accuracy specifications in terms of geometrical tolerances and surface finish. Lasers and electric discharge machining (EDM) are widely used to produce micro-components and are similarly unconventional thermal technologies. In general, a laser is particularly appreciated by the industry for the excellent machining speeds and for the possibility to machine essentially any type of materials. EDM, on the other hand, has a poor material removal rate (MRR) but can produce microparts on only electrically conductive workpieces, reaching high geometrical accuracy and realizing steep walls. The most common micro-application for both the technologies is drilling but they can make also milling operations. In this work, a comparison of femto-laser and EDM technologies was made focusing on micro-milling. Two features were selected to make the comparison: micro-channels and micro-pillars. The depth was varied on two levels for both features. As workpiece material, aluminum, stainless steel and titanium alloy were tested. Data regarding the process performance and the geometrical characteristics of the features were analyzed. The results obtained with the two technologies were compared. This work improves the knowledge of the micro-manufacturing processes and can help in the characterization of their capabilities.

Effect of the parameters in electromagnetic field assisted electric discharge machining

The electric discharge machining is a non-conventional machining process, in which the spark is electric spark is generate in gap between the work piece and electrode. Due to heat generated by spark in between the workpiece and electrode, the material get vaporized from small area form workpiece and get cool down with the help of dielectric fluid. In present study low carbon mold steel use as a work piece and copper electrode is used. The electromagnetic field included in the process to analyze the effect of the input parameters on the machine response parameters like MRR and the surface roughness value (Ra). The study is done on EDM process with and without EMF by varying the input parameters Ton (μs) and keeping the other parameters constant (Toff (μs), Current (A) & Voltage (V)). The set of the neodymium magnets are used in the set up having 4500 gauss units. The circular plate is designed to hold the neodymium magnets nearer to the work piece using CATIA V5 version. 3D printer is used to fabricate the circular plate that holds the electromagnets precisely near to the area under spark to have a maximum effect of EMF in the EDM process. The experimentations shows that response parameter shows good output at pulse on time of 200 ms and 300 ms with and without EMF respectively.

Optimization of micro-EDM drilling on titanium alloy (Ti-6AL-4V) using RSM and Neural Network

In modern manufacturing industries, micro machining technology is widely used to machine micro parts for various applications such as in MEMS, die and tool industries, etc. Micro electric discharge machining (Micro-EDM) is widely used in die and tool making. This paper investigates three different input machining parameters such as pulse on time, pulse off time, and servo voltage of micro electric discharge machining performances of tool wear (TW) and Diametrical accuracy (DA) of a hole on titanium alloy (Ti-6Al-4V) using copper micro electrodes of ϕ 400μm. The experiments ate conducted out with the Box-Behnken design of Response Surface Methodology (RSM). The neural network is used for the optimization of multi response by fitting the regression model. ANOVA is also performed to find the significant contribution of the machining parameter. The predicted optimal machining values with the maximum error of 12.72% for tool wear and 8.78% for diametrical accuracy was achieved on comparing with experimental results.