| In the conventional wire drawing process, the deforming force and friction due to the acute deformation are great. Therefore, the broken wire and rough surface often come into being. The drawing of difficult-to-draw materials, such as the pure titanium, titanium alloys and the ultra fine-metal wire, can not been processed. In order to solve these problems, it is urgency to study the technology of ultrasonic-vibration drawing, and explore the effective technology and method. Hence, the mathematical model of the mechanism of ultrasonic drawing, the simulation of ultrasonic drawing, and composite ultrasonic-vibration wire drawing and the drawing of difficult-to-draw materials with ultrasonic were comprehensively studied in this dissertation.Firstly, the mechanics analysis of the technology for the conventional and ultrasonic vibration drawing was performed. The force equilibrium equations in the calibrating strap and the reducing strap were built. The non-local friction theory presented by Oden was used in stead of the classical Column friction model. The Taylor series and the Mises yield criterion were used. The mathematical model on friction distribution, contact pressure distribution and the drawing force in the calibrating and reducing straps were built. A numerical method was developed in MATLAB?. This mathematical model provides method and theoretical support for the research on the drawing force and friction of the ultrasonic vibration drawing.Secondly, simulation of the conventional and ultrasonic vibration drawing was carried out in ANSYS?. A new approach of same-step loading, multi-step solving was developed by reasonable simplification that the sine wave of ultrasonic vibration is transformed into the triangle wave, which has the same frequency, phase and amplitude of vibration as the sine wave. The difficulty on how to transferring ultrasonic vibration to the drawing dies is solved. The results of the drawing force, deformation, stress, strain and friction in the ultrasonic vibration drawing simulation were analyzed and compared with those in the conventional drawing simulation and the results obtained by the above mathematical model.Then, the ultrasonic vibration system was designed and manufactured by using the classical dynamics method and the four-terminal network method. The dynamic characteristic of the transducer (including modal analysis, harmonic response analysis and transient analysis) was analyzed. The electricity matching of the ultrasonic vibration system was tested. The performance parameters of the system were measured on the Polytec PSV-400-M2 laser vibration meter and HP4294A resistance analyzer.In order to promote the practical application of the technology, the wire drawing using ultrasonic vibration at the speed of practice was carried out firstly on the LH-200/17 drawing machine in Harbin Cable Factory. The affect of the speed on the drawing force was obtained and the changing regular of the periodic of the tension regulator. The results show that the drawing force reduced by 4%, and the ultrasound vibration effectively prolongs the period of tension regulation more than 3 times. And the regular tips of the drawing force and the broken wire were obviously reduced. These factors make the drawing process stable, and greatly improve the unevenness of the surface of the products. The results demonstrate that the drawing with ultrasound can increase the processing efficiency, reduce the power cost. The SEM pictures show that the ultrasonic vibration improves the contact status between the wire and the die, reduce the scratch marks and pits on the wire surface, and improve the surface quality. This demonstrates that the vibrating energy can be effectively transferred to the internal of the wire, which can gentle the deformation of the crystal and distortion of the crystal lattice and reduce processing hardening and improve the service performance and processing properties.Finally, a composite ultrasonic-vibration system for the ultrasonic drawing was developed, by considering the different effects caused by different types of ultrasonic vibration, processing difficulties of the difficult-to-draw material and the expanding demand of non-conventional machining. The convenient, brief and reliable design method for the ultrasonic transducer was explored. In experiments, the three kinds of forms of ultrasonic vibration (longitudinal, radial and composite) were applied on the brass wire. The drawing force and the topography of the drawn wire were measured. The results show that the effect of the composite vibrating form is best. It can more effectively reduce the drawing force and prolong the periodicity of tension regulation. It almost eliminates the phenomena of broken wire. The stainless steel wire and the pure titanium wire were directly drawn in the composite ultrasonic vibrating system. Their success break the domestic deadlock of direct drawing for the pure titanium wire the, and demonstrates that the composite vibrating system can effective solve the processing problem of the difficult-to-draw material.The present work will be widely used aerospace, equipment manufacturing, medical device, information industry and automobile industry. It will bring great market economic returns in the aspects of reducing drawing force, improving processing efficiency and processing difficult-to-draw material.
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