【作者】 曾伟民；

【导师】 徐西鹏； 裴志坚；

【作者基本信息】 华侨大学 ， 机械制造及其自动化， 2006， 博士

【摘要】 旋转超声钻削是一种先进陶瓷材料孔加工的高效加工方法。它是一种集普通超声钻削和磨削加工为一体的复合加工方法。相对于普通超声钻削，旋转超声钻削无论在降低加工成本还是提高加工效率方面都有了革命性的变化。 本文在深入剖析旋转超声钻削技术现状以及存在问题的基础上，对旋转超声钻削先进陶瓷的实验和理论研究进行了深入的研究。论文的主要研究工作概括如下： 1、在恒速进给加工条件下，实验比较了旋转超声钻削和普通钻削对加工过程的影响；系统研究了在恒速进给加工条件下，旋转超声钻削参数对加工过程的影响。 2、分别推导出普通超声钻削和旋转超声钻削过程中，工件在单颗磨粒作用下的应力场分布模型；并从工件应力场的角度解析了旋转超声钻削材料去除率高于普通超声钻削材料去除率的现象。 3、分别基于脆性断裂和塑性变形两种材料去除机理，推导出简单实用的旋转超声钻削材料去除率理论模型，并根据所推导的理论模型进行仿真，探讨了旋转超声钻削加工参数(超声振动振幅，超声振动频率，工作压力，旋转速度，磨粒数目，以及磨粒尺寸)对材料去除率的影响。 4、通过使用数字显微镜跟踪观察旋转超声钻削过程中金刚石工具表面形貌变化，研究了旋转超声钻削先进陶瓷过程中的工具磨损机理。 5、针对旋转超声钻削过程中排屑困难的难题，通过改进旋转超声钻削的传统金刚石工具，提出一种新型的加工工艺—断续旋转超声钻削；并对断续旋转超声钻削的加工效果进行了实验验证。 通过实验研究和理论分析，本论文取得的主要成果和结论有： 1、在恒速进给加工条件下，旋转超声钻削比普通钻削更具有加工优势。相对于普通钻削，旋转超声钻削能有效降低切削力，降低加工孔的表面粗糙度，以及避免先进陶瓷工件在加工中的破裂。 2、在恒速进给加工条件下，主轴转速、进给速度、以及超声功率对旋转超声钻削加工过程具有显著的影响。旋转超声钻削过程中，切削力随着旋转速度或超声功率的提高而降低，随着进给速度的提高而提高。加工孔表面粗糙度随着旋转速度的提高而降低。 3、从分析旋转超声钻削应力场可知，旋转超声钻削先进陶瓷过程中，工件应力场分布向磨粒的运动方向倾斜，在磨粒与工件接触区的前下方处容易产生磨削裂纹。该磨削裂纹在磨粒的划擦和撕裂作用下，会进一步向工件表面扩展，形成切屑，这有利于提更多还原

【Abstract】 As one of the cost-effective machining methods for advanced ceramics, rotary ultrasonic drilling (RUD) is a hybrid machining process that combines the material removal mechanisms of conventional ultrasonic drilling and diamond grinding. Compared with conventional ultrasonic drilling, RUD revolutionizes the whole sector both in reducing the cost and in improving the efficiency.Based on the thorough analysis on the state of arts of RUD and the existing problems, the experimental and theoretical studies on RUD are conducted in this thesis. The main work of this thesis can be summarized as follows:1. Under the machining condition of constant feed rate, the effect of RUD and conventional diamond drilling on drilling process are compared. The effects of the process parameters of RUD on drilling process are systematically conducted.2. Based on a single-point diamond grinding model and the elasticity theory, the stress field model in conventional ultrasonic drilling and RUD are deduced. Based on the deduced models and the indentation fracture mechanics, material removal rate (MRR) in RUD being higher than that in conventional ultrasonic drilling is explained.3. Based on the two modes of material removal (brittle fracture mode and ductile mode), two MRR theoretical models in RUD are developed. The influences of parameters (ultrasonic amplitude, ultrasonic frequency, static force, rotating speed, grit number, and grit diameter) on MRR are studied in RUD.4. The tool wear mechanism is studied by using a digital microscope to observe the topography of the diamond tool in RUD of advanced ceramics.5. A new technical method— intermittent rotary ultrasonic drilling (IRUD)— is introduced by improving the conventional tool of RUD. The experiment is conducted to compare the effect of IRUD and conventional RUD on drilling process.Through experimental study and theoretical analysis, the following achievements and conclusions can be obtained:1. Under the machining condition of constant feed rate, RUD is superior to conventional diamond drilling. Compared with conventional diamond drilling, RUD can significantly decrease the cutting force, decrease the surface roughness of drilled holes, and avoid the fracture of advanced ceramics during RUD process.2. Spindle speed, feed rate, and ultrasonic power have significant effects on RUD process更多还原