Study On The Hard-brittle Machining Technology And Mechanism Based On Ultrasonic Vibration Assisted Electroplated Diamond Wire Saw

Along with the increasingly expended applications of the hare-brittle materials, the demands of its cutting technology become more and more strict and important. In order to solve some technical problems in cutting of hard-brittle materials, especially the rare and valuable hard-brittle materials, a new cutting technology was reported in this paper. Ultrasonic wire cutting is a new technology, at present it is becoming one of the investigation hotspot in ultrasonic machining domain. The mechanism and processing performances of ultrasonic wire cutting are studied by means of theoretical analysis combined with experiment presented in this dissertation to improve the technology.Basing on analysis of different parts of machine tool,general structure plan was established. Horn, transducer ,pilot wheel and other key parts were detailed analysis and design apply to acoustics and mechanical vibrations theory. Has studied and researched the connections between the parts. The material removal mechanism of ultrasonic wire cutting is studied. The material removal rate of ultrasonic wire cutting is proposed by using the theory of indention fracture. The model shows that influencing factors of the material removal rate are to-and-fro frequency, lateral pressure, vibration frequency, amplitude and workpiece material performances, ect. The experiment proved that its material removal rate is 2.5~4.5 times of the ordinary and the surface quality had enhancement and improvement.The theoretical model of cutting forces was built up. The influences of cutting speed, saw parameters, and sample properties on the cutting forces were taken into account based on analyzing the cutting force of a single diamond grain. The finite model of a single diamond grain and nickel-plating layer near by the grain was built up. The reasons of diamond grain's breaking up and falling off were analyzed according to the model. It shows that, during the cutting process, the stress on the diamond grains and the contact stress between the diamond grains and nickel layer were very low, that could not make diamond grains breaking up and falling off. The breaking up and falling off of the diamond grains were mainly caused by the action of mechanical impact and the cutting heat caused by the friction. So that the diamond grains would be falling off and breaking up. The cutting forces and cutting heat were lower as the same condition of the ordinary, the life was increased.