氧化锆陶瓷义齿超声振动辅助磨削技术研究

发布时间：2018-01-02 18:05

本文关键词：氧化锆陶瓷义齿超声振动辅助磨削技术研究　出处：《南京理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着全瓷牙和全锆牙的逐步推广,氧化锆陶瓷作为一种最接近天然牙的口腔修复材料,以其良好的美学特性、生物相容性、稳定的化学性能以及耐磨损,使其在口腔修复领域的应用日益突出。然而,现有义齿加工流程存在着二次烧结缩放精度难以控制、病人等待时间长等问题。由于完全烧结氧化锆陶瓷是典型的难加工材料,并且义齿表面有着复杂的曲面形貌,传统的加工技术很难对完全烧结的氧化锆义齿其进行一次成形加工。以上问题严重制约了氧化锆陶瓷在口腔修复领域的应用。本文提出采用超声振动辅助磨削技术实现对完全烧结氧化锆口腔修复体的直接加工。通过对超声振动辅助磨削力、磨削温度理论建模研究以及加工表面质量实验研究等工作,对牙科氧化锆陶瓷超声振动辅助磨削基础理论以及加工工艺开展了可行性研究。主要研究内容如下:(1)根据超声振动辅助磨削的特点,分析了在超声振动辅助下单颗金刚石磨粒的运动学特性、材料去除体积、振动参数对磨粒切削轨迹的影响。同时通过分析横向裂纹干涉和振动参数对有效磨粒数量的影响以及磨粒的受力情况,结合压痕断裂力学理论以及脆性材料断裂去除机理,提出了一种沿进给方向的超声振动辅助磨削力的预测模型。通过理论分析和验证实验相结合的方法,阐明了金刚石刀具参数、磨削工艺参数、超声振动参数等因素对磨削力的影响规律,验证了该磨削力模型的合理性和有效性。(2)通过对磨削温度场的分析,并结合已建立的磨削力预测模型和超声振动辅助磨削加工的特点,提出了一种完全烧结氧化锆陶瓷超声振动辅助磨削温度的预测模型。并通过开展超声振动辅助磨削温度实验,阐明了磨削工艺参数、振动参数等因素对磨削温度的影响规律,并验证了模型的合理性和有效性。(3)开展了氧化锆陶瓷超声振动辅助磨削表面质量实验研究,分析了磨削参数、超声振动参数对牙科氧化锆陶瓷表面粗糙度、表面纹理、以及表面形貌的影响规律。并通过与普通磨削对比,分析了超声振动辅助磨削的优势。实验结果表明:与传统金刚石磨削相比,超声振动辅助磨削能有效的降低磨削表面粗糙度和表面损伤,同时可改善磨削表面形貌。为超声振动辅助磨削加工技术在口腔修复领域的应用提供了理论和实验基础。
[Abstract]:With the gradual promotion of all-ceramic teeth and all-zirconium teeth, zirconia ceramics, as a kind of dental restorative material closest to natural teeth, has good aesthetic properties, biocompatibility, stable chemical properties and wear resistance. Because of its increasingly prominent application in the field of dental prosthesis, however, the existing process of denture processing has the difficulty to control the accuracy of secondary sintering scaling. Due to the fact that completely sintered zirconia ceramic is a typical refractory material and the surface of denture has complex surface morphology. It is very difficult for traditional processing technology to form completely sintered zirconia denture. The above problems seriously restrict the application of zirconia ceramics in the field of oral prosthodontics. The ultrasonic vibration assisted grinding technique is proposed in this paper. Direct machining of completely sintered zirconia prosthesis was realized by ultrasonic vibration assisted grinding force. Research on grinding temperature theory modeling and experimental research on surface quality. The feasibility of ultrasonic vibration assisted grinding for dental zirconia ceramics is studied. The main contents are as follows: 1) according to the characteristics of ultrasonic vibration assisted grinding. The kinematics characteristics and material removal volume of diamond abrasive particles ordered by ultrasonic vibration are analyzed. The influence of vibration parameters on the cutting path of abrasive particles, and the influence of transverse crack interference and vibration parameters on the effective abrasive particle number and the stress of the abrasive particles are analyzed at the same time. Combined with the theory of indentation fracture mechanics and the fracture removal mechanism of brittle materials, a prediction model of ultrasonic vibration assisted grinding force along the feed direction is proposed. The influence of diamond tool parameters, grinding process parameters and ultrasonic vibration parameters on the grinding force is expounded. The rationality and validity of the grinding force model are verified by analyzing the grinding temperature field. Combined with the established grinding force prediction model and ultrasonic vibration assisted grinding processing characteristics. A prediction model of ultrasonic vibration assisted grinding temperature for sintered zirconia ceramics is presented, and the grinding process parameters are illustrated by ultrasonic vibration assisted grinding temperature experiment. The influence of vibration parameters on grinding temperature is verified. The rationality and validity of the model are verified. The experimental research on surface quality of Zirconia ceramics by ultrasonic vibration assisted grinding is carried out, and grinding parameters are analyzed. The influence of ultrasonic vibration parameters on the surface roughness, surface texture and surface morphology of dental zirconia ceramics was studied. The advantages of ultrasonic vibration assisted grinding are analyzed. The experimental results show that ultrasonic vibration assisted grinding can effectively reduce the surface roughness and surface damage compared with traditional diamond grinding. At the same time, the grinding surface morphology can be improved, which provides a theoretical and experimental basis for the application of ultrasonic vibration assisted grinding technology in the field of dental repair.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R783.1;TQ174.6

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