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The mask jet electrochemical deposition was used to deposit the large-scale micro cylinders array in this study. The effect of the pulse peak current density, pulse frequency, pulse duty cycle, injection pressure and scanning speed on the deposition characteristics (i.e. deposition height, surface roughness and surface quality of micro cylinders) have been investigated. The experiment results showed that the mean height and the surface roughness of micro cylinders increased form the peak current density. Moreover, due to a high pulse frequency provided a shorter pulse on-time, and significantly facilitating the renewal of the ion concentration in the electroforming fluid. A higher pulse frequency and larger duty cycle provide a better deposition characteristic. The injection pressure was found to have a significant effect on the height, the surface roughness and surface appearance of micro cylinders. Furthermore, when using higher scanning speed, the crystalline particles of the cast layer decrease, significantly decreasing the surface roughness. Based on discussed, the pulse current density of 12 A/dm2, a pulse frequency of 3000 Hz, a pulse duty cycle of 30%, a jet inlet pressure of 80 kPa, a scanning speed of 8 mm/s and a number of scans of 100 is optimal parameters. Finally, by using these parameters, a large-area micro cylindrical array structures with a height of 22.53±2.46 µm and diameter of 205±3.21 µm were successfully fabricated. It can be concluded that the mask jet electrochemical deposition is a simple method to realize the electrode-position of large-area array structures. [ABSTRACT FROM AUTHOR]

The accumulation of debris between the inter-electrode gap caused by inefficient flushing during the micro-electrical discharge machining (micro-EDM) process leads to severe tool electrode wear and decreases the machining accuracy of micro-holes. In this study, a novel method using tool electrode spiral motion feed mode combined with fixed reference axial compensation (FRAC) is proposed to promote the debris evacuation and improve the machining accuracy of micro-holes. Different depths of micro-holes in titanium alloy were drilled using the tool electrode linear motion feed mode and spiral motion feed mode combined with FRAC and without compensation. The process parameters were optimized and determined by means of response-surface experiments to improve machining accuracy and machining efficiency. The results showed that the tool electrode spiral motion feed mode can improve the debris evacuation more effectively than the tool electrode linear motion feed mode. The micro-holes without cone at the bottom could be fabricated using the tool electrode spiral motion feed mode. The introduction of FRAC could improve the depth error of micro-holes furtherly. A high accuracy micro-hole with a depth error of only 0.21% could be fabricated efficiently under the condition of the optimal process parameters. The tool electrode spiral motion feed mode combined with FRAC has an obvious advantage in the fabrication of high accuracy micro-holes during the micro-EDM process. [ABSTRACT FROM AUTHOR]

The electrochemical discharge machining (ECDM) is an advanced machining technology used to fabricate micro-holes in glass. In this study, a sheet tool electrode is employed to increase electrolyte circulation in machining zone. The effect of pulse voltage, frequency, duty cycle, electrolyte concentration, and tool rotation speed on the geometric properties of micro-holes were evaluated. The results showed that when using a sheet tool electrode, the machining depth increased by 42.9 %, and the machining efficiency increased by 51.1 %, while the entrance diameter was reduced by 13.9 % than cylindrical tool electrode. Additionally, the heat-affected zone (HAZ) and entrance hole surface quality is improved. On the other hand, the Taguchi method was employed to analyze the relative importance of the machining parameters on geometric characteristics of micro-holes (i.e. drilled depth and entrance diameter of micro-holes). Finally, the entrance hole overcut of 148 µm was successfully fabricated with a depth of 2520 µm. It was discovered that using a sheet tool electrode is a simple method for machining a deep micro-hole with high machining efficiency and a range entrance hole diameter overcut that is acceptable. [ABSTRACT FROM AUTHOR]