**1. Introduction**

Precision is essential in the field of micromanufacturing. High dimensional accuracy is an essential target requiring extreme attention to every aspect of production. Fabricating micro polygonal profiles is difficult to create using traditional machining processes [1]. Maintaining corner and angular precision in polygonal profile products may be difficult despite its importance. As a result, many manufacturers are looking at new technologies and techniques that will enable them to achieve more precision and accuracy in their micromanufacturing processes. Sophisticated machining processes can meet the demands of modern industry. Electrochemical machining

(ECM) [2], a technique that dissolves metal using a conductive fluid, is often used in the aerospace and medical sectors. Laser beam machining (LBM) is utilized in the electronics and automotive sectors to remove material with a strong laser. Ultrasonic machining (USM) frequently removes material using ultrasonic vibrations and produces micro-components. Electron beam machining is predominantly used in aerospace to remove material using an electron beam. For high-precision and highspeed machining in aerospace and medical applications, electrochemical discharge machining (ECDM) is a hybrid technique that combines electrical discharge machining (EDM) and electrochemical discharge machining (ECM). Electrical discharge machining (EDM) [3] is a non-contact technique that erodes material using electrical sparks. It is best suited for machining complicated structures and harder materials like titanium, carbide, and tool steels. Among these, EDM is particularly noteworthy for its ability to machine any conductive material, regardless of hardness, and create complex shapes with high precision. Micro-EDM is the most commonly used variant, especially for micro-structures (holes, slots) and complicated 3D profiles [4].

The Micro EDM process has two major limitations: its material removal rate is comparatively low compared to other processes, and the tool wear rate during EDM is high. Various approaches and methods are used for predicting and optimizing the TWR and MRR of micro EDM. Bellotti et al. [5] used data-driven methods to create regression models that could predict tool wear and material removal rates (MRR and TWR) in micro-EDM blind holes. By using process monitoring data as input for their regression models, the researchers reduced errors in predicting MRR and TWR by approximately 65 and 85%, respectively. Pragadish et al. [6] greatest impact on material removal rate (MRR) and tool wear rate (TWR) while drilling silicon steel and optimizing the micro EDM process parameters to achieve high MRR with reduced tool wear rate in coated tools and found dielectric cardanol oil has major influence and at gap voltage of 50 V, Green dielectric (%) of 05 and coating thickness of 1 μm, got optimum MRR of 9.69 mm3/min and a tool wear rate (TWR) of 1.09 mm3/min. Arunnath et al. [7] fabricated a hole on T6 aluminum alloy using aluminum 7075 nano boron carbide metal matrix composites using EDM, and ANOVA was used to analyze the experimental results to know the percentage of contribution of each parameter on MRR and TWR. Sanghani et al. [8] developed a mathematical model using a regression equation of MRR and TWR in EDM based on a fraction-of-energy approach. Vidya et al. [9, 10] investigated the dimensional accuracy of micro holes and microchannels fabricated EN-24 alloy steel using die sinking EDM process and found that the micro holes have a roundness error of 46.33 μm, and the microchannels have a straightness tolerance of 13.51 μm. Geometric tolerance greatly affects the performance and lifetime of the mechanical parts. Microcavity was created by Abhinav et al. [11] discovered that the diametral length of the microcavity varied between 748 and 800 μm.

The manufactured micro holes using micro EDM show extremely less circularity variation. Near the edges of the machined holes, some recast layer development that varies between 6.5 and 7.5 μm was observed. According to Huan et al. [12], it is necessary to compensate for micro-electrode wear to maintain the dimensional consistency and accuracy of micro-hole arrays in micro-EDM drilling. Mouralova et al. [8] studied the fabrication of a precise slot of size 5000 × 170 μm in a copper foil with a thickness of 125 μm and used the same copper foil as a tool in micro EDM. Unune et al. [13] studied the dimensional accuracy and surface quality of micro-channels with

### *Effect of Process Parameter Variations on Triangular Microcavity Fabrication Using Micro-EDM DOI: http://dx.doi.org/10.5772/intechopen.113233*

low-frequency vibration assistance in micro-electro-discharge milling. They found that the discharge energy significantly affected the amount and size of the globules formed during μ-ED milling. Rafaqat et al. [14] produced non-circular holes of three shapes (square, triangle, and hexagon) in AISI D2 steel. They evaluated the performance of three response characteristics: material removal rate, tool wear rate, and land wear.

These limitations impact the dimensional accuracy of the machined feature. Researchers continuously improve the material removal rate and reduce the tool wear rate. In this investigation, the performance of micro EDM was evaluated in fabricating a polygonal structure, specifically a triangular profile. Non-circular shaped holes, commonly used in the mold industry, were selected as the machining profiles. The performance was evaluated against two triangle features, included angle between sides and corner radius, by varying the input parameters such as voltage, capacitance, and feed.
