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In the present investigation, a continuous wave fiber laser with maximum power of 400 W was used to cut a glass fiber reinforced plastic sheet of 4.56 mm thickness using Nitrogen as assisting gas. The influence processing parameters such as laser irradiance, gas pressure, and cutting speed on the cut surface quality were investigated by using response surface methodology. The different responses of laser cut surface such as upper kerf width, taper percentage along the cut depth, and heat-affected zone on the top surface were measured to analyze the influence of input process parameters on the responses. A statistical analysis on the obtained results was conducted and found that the optimum values of different input process parameters were laser irradiance: 8.28 × 105 watt/cm2, cutting speed: 600 mm/min and assisting gas pressure: 7.84 bar. The corresponding values of responses were upper kerf width: 177.4 µm, taper 0.73%, and heat-affected zone on top surface: 109.23 µm. The confirmation experiments were conducted with the obtained optimum parameter setting and observed that the predicted values and experimental values for upper kerf width, taper percentage and top surface heat-affected zone were within the error limits of 2.52%, 1.84%, and 0.45%, respectively. Furthermore, damages like loose fibers, interlayer fractures, evaporation of matrix material and fiber breakages were observed.

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Nickel-Titanium alloy (Nitinol) is an excellent shape memory alloy (SMA) for Micro electro-mechanical systems (MEMS) particularly in biomedical applications owing to its three excellent features like shape memory effect (SME), superelasticity, and biocompatibility. The fabrication of micro features on Nitinol SMAs through conventional machining has been challenging due to its temperature-dependent material transformation properties. Micro electrochemical machining (micro-ECM), a nonconventional machining method for conductive material irrespective of strength and hardness has the potential for microfeature fabrication on Nitinol. This study presents the investigation on electrochemical dissolution behavior of Nitinol in different electrolytes for micro-ECM. The in uence of electrolytes on the nature of dissolution of Nitinol has been studied by fabricating microchannels in three levels of parameters containing applied voltage and electrolyte concentration. The rst three electrolytes were all aqueous neutral electrolytes i.e. sodium chloride (NaCl), sodium nitrate (NaNO 3 ), and sodium bromide (NaBr). For profound analysis of dissolution behavior and its in uence on machining performance, potentiodynamic polarization (PDP) tests of Nitinol were performed in aqueous NaCl, aqueous NaNO 3, and aqueous NaBr solutions. The PDP tests that are conducted here are cyclic voltammetry (CV) and linear sweep voltammetry (LSV). The three aqueous solutions were utilized for microchannel fabrication in Nitinol through micro ECM in three levels of parameters out of which aqueous NaNO 3 was successful in fabricating microchannel. Then nonaqueous electrolyte of ethylene glycol-based NaNO 3 has been used to fabricate microchannels with lower depth overcut (DOC), width overcut (WOC), and length overcut (LOC) with respect to aqueous NaNO 3 electrolyte.

We analyzed the efficient electrochemical dissolution of tungsten carbide –cobalt alloy (WC-Co) micro-tools for micromachining operations with an eco-friendly electrolyte. One of the essential factors in efficient anodic dissolution is the selection of appropriate electrolytes. Sulphuric acid (H2SO4) is extensively used in the electrochemical process to dissolve WC-Co due to its higher dissolution rate and efficiency, but toxicity of H2SO4, even at moderate concentration, poses a significant threat to the operator and the environment. Hence in this investigation, an eco-friendly electrolyte has been proposed which is a combination of sodium nitrate (NaNO3) and a complexing agent citric acid (C6H8O7), that not only gives a higher dissolution rate of WC-Co but also gives similar dissolution efficiency that of H2SO4. Detailed experimentation to optimize the concentration of complexing agent in the eco- friendly electrolyte was carried out through micro wire-electrochemical machining (micro-WECM) and was analyzed using yield parameters, topographical and material surface analysis as well as electrochemical analysis. This eco-friendly electrolyte produces higher dissolution rate and better surface finish in different levels of parameters in comparison to H2SO4. Potentiodynamic polarization test through linear sweep voltammetry (LSV) showed maximum current density for WC-Co alloy in the proposed eco-friendly electrolyte.