Papers by Author: B.X. Jia

Abstract: Block electrode discharge grinding is an effective approach to produce micro rods. However, it is difficult to fabricate the rods into desired miniature and precision. To solve this problem, the tangential feeding method is proposed to control the finish size of micro rods. With this method, the micro rod is first fed in its radial direction, and then in the tangential direction for an enough distance. The wear of the block electrode decreases gradually from the start to the end, and the wear in the end can be neglected. Experiments indicate that the large capacitance or voltage can obtain high machining speed, while the small ones can gain thin micro rods. Based on this result, the policy of delaminating grinding is adopted to gain enough thin micro rods at a high machining speed. The Φ5µm micro rods can be ground with this method. SEM results show that the relative error of the size control is less than 10%.

Abstract: To perform several micro-machining on same machine tool, a micro machining equipment was researched and developed. The equipment adopts some high and new technologies. It is equipped with high precision XYZ stage, a spindle with high rotation accuracy and variable rotation speed, a granite worktable, a block electro discharge grinding unit for machining micro rod, a ultrasonic vibration unit for workpiece vibrating, a high frequency pulse power supply for micro-ECM and a video microscopic system with high enlargement factor. The equipment can perform micro electro discharge machining (EDM), micro electrochemical machining (ECM), micro ultrasonic machining (USM) as well as their combination. It can also machine 3D microstructures. A series of experiments were carried out. Using micro-EDM, micro rods with the diameter of less than 5µm were ground on block electrode, micro holes and 3D microstructures were obtained. Shaped holes were machined by using combination of micro-EDM and micro-USM. A micro hole with the diameter of 100µm was machined via micro-ECM.