Papers by Author: Dong Wang

Abstract: Sintered NdFeB permanent magnet is widely used in many applications because of its excellent magnetic property. But its poor corrosion resistance has been cited as a potential problem with its use.Nickel phosphorus (Ni–P) alloys systems are very attractive due to their good corrosion and wear resistance behavior. In this paper the ultrasonic effect is used in electro deposition. Experimental results show that the ultrasonic improve the deposition surface quality.

Abstract: In this study, the electrical discharge machining (EDM) of sintered NdFeB magnet was investigated. The surface characteristics were studied in terms of machining parameters. Correlation between the surface roughness, hardness, recast layer and the machining parameter were analyzed. Results show that an excellent machined finish can be obtained by setting the machine parameters at low pulse energy. Low pulse energy reduces the frequency of bursts of dielectric fluid and melt expulsions.

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.

Abstract: Sintered NdFeB permanent magnet is widely used because of its excellent magnet property. But there is few report of machinbility of it. This paper presents an experimental investigation of the machining characteristics of sintered NdFeB permanent magnet using a combination process of electro-discharge machining (EDM) with ultrasonic machining (USM). The EDM / USM machining mechanisms are integrated to improve the machining efficiency. During the experiments, concentration of abrasive in the dielectric fluid is changed to explore its effect on the material removal rate (MRR). MRR of EDM /USM, conventional EDM and tool vibration aided EDM are compared, REWR and machined surface characteristics are also compared between them. From the experimental results, it is concluded that the combination EDM/USM process can increase the MRR and decrease the thickness of the recast layer. In the combination process, an appropriate abrasive concentration can improve its machining efficiency.