| dc.description.abstract | This study prepared micro pear-shaped tools using ultrasonic-assisted micro electrochemical techniques. It used ultrasonic assisted vibration to prepare tungsten carbide micro pear-shaped tools. When wire-cutting electrical discharge machining, sintering process and other methods are adopted to prepare micro pear-shaped tools, but there are problems of likely forming of surface defects and high cost and requiring long processing time. Hence, it is difficult to process micro pear-shaped tools with better dimension precision and surface appearance. In order to overcome the above difficulties, this study designed a three-plate electrode, and employed jet flow electrolyte to supply fixture and assistance of ultrasonic-assisted vibration to prepare micro pear-shaped tools using electrochemical techniques. This study also discussed the influence of different machining parameters, such as working voltage, upper electrode power supply time, pulse off time and ultrasonic vibration stage, on various processing characteristics, such as maximum diameter, minimum diameter, ellipse major axis length 1, ellipse major axis length 2, consumption length, overall diameter difference and ellipticity. It further analyzed change of surface components of micro pear-shaped tools after machining.
Experimental results show that ultrasonic vibration has a pumping function, and it can accelerate electrolyte renewal in machining gap and rapidly remove reaction heat and various electrochemical products in machining gap. Comparing with the situation without assistance of ultrasonic vibration, better appearance of micro pear-shaped tools and smaller dimensions of micro pear-shaped tools can be obtained. Under parameter combination of working voltage of 9V, upper electrode power supply time of 20s, pulse off time of 40s, and ultrasonic vibration stage is 15, better dimensions of micro pear-shaped tools can be obtained (maximum diameter of 181m, minimum diameter of 54m, ellipse major axis length 1 of 168m, ellipse major axis length 2 of 543m, consumption length of 1288m, ellipticity of 1.99 and overall diameter difference of 126m), the overall appearance of micro pear-shaped can be improved effectively. | en_US |