Papers by Author: Guang Ming Yuan

Abstract: Sintered NdFeB permanent magnet is widely used in many areas because of its excellent magnet property. In this study, the machining parameters of electrical discharge machining (EDM) are varied to study the effects of electrical discharge energy on material removal rate and surface roughness of NdFeB magnet. Moreover, the micro-cracks on the machined surface induced by EDM are also examined. The experimental results reveal that the MRR increases with the electrical discharge energy. The number of surface cracks on the machined surface increases with the enhancement of discharge energy Thus, using EDM process to machine sintered NdFeB magnet depends on setting the machining parameters to prevent surface crack.

Abstract: Sintered NdFeB magnet is widely used in many areas because of its excellent magnet. This paper studies the effect of ultrasonic vibration of tool on electrical discharge machining of it. Experiments were carried out on self-made equipment and material removal rate(MRR) against pulse-on time, MRR versus peak current and machined surface results with and without ultrasonic employment were analyzed. Results show that MRR of the ultrasonic assisted electro-discharge machining would be up to five times higher than MRR of the conventional EDM for small pulse durations and low discharge currents. The machined surface of US/EDM is finer than EDM because of less arcing and short circuit pulses. There are less cracks on the surface.

Abstract: Worm cam mechanism is a common indexing mechanism which is widely used in automatic machinery. Because of its high transmission precision requirements, the mechanism has high demands on the cylinder cam. The machining methods of cylinder cam are unique and the methods of special machine tool and NC machining are the two methods that general adopted in the machining of it. In this paper, the method of CNC Programming which is used for machining cylinder cam in 5-axeses high speed DMU 70eVolution Machining Center is introduced. The machining principle of cylinder cam has been studied, and the mathematical model for CNC Programming has also been worked out. The automated compensation of cutting tool’s radius is used in this field for the first time.

Abstract: A new kind of ultrasonic machining method named ultrasonic machining aided tool rotation is proposed for sintered NdFeB permanent magnet. In the process abrasive slurry enters the machining area through holes in the rotary tool which can assure the grains easily enter the machining surface slurry. Its machining mechanisms are studied and material removal model is developed. Experimental research was carried out on self-made equipment. Experimental results were accordance with the developed model. It is proved that this new kind of ultrasonic machining technology is suitable to machine deep hole for sintered NdFeB material.