Study On Rotary Ultrasonic Face Milling Of Quartz Glass Based On Material Removal Mechanism

Quartz glass has high temperature resistance,low expansion coefficient,thermal shock resistance,high chemical stability,excellent performance,and is widely used in chemical industry,electronics,metallurgy and national defense and other industrial fields.,but the physical and mechanical properties of quartz glass,especially toughness and strength,is very different the metal material.The load of the material is easy to exceed the yield limit of the material and fracture damage while in the processing,therefore,the traditional processing method is not only with low processing efficiency but also with other issues like tool wear,broken collapse.Rotary ultrasonic machining provides an effective solution for efficient removal of such hard-brittle materials with its excellent processing capabilities.In this paper,the high frequency rotating ultrasonic milling process and material removal mechanism of quartz glass are discussed and analyzed from four aspects: material behavior,crack propagation method,kinematic modeling of tool abrasive and trajectory simulation and influence of process parameters.The main work of the paper mainly from the following aspects:(1)Based on the ANSYS/LS-DYNA finite element simulation platform,the simulation process of the rotary ultrasonic milling of quartz glass is carried out.The distribution characteristics of the stress field in the tool-working area during the material removal are analyzed.The effects of the high-frequency reciprocating impact,the role of the crack initiation and expansion and the mechanism of material removal are also clarified.(2)The influence of the feed speed,the spindle speed and the ultrasonic vibration frequency on the three-dimensional trajectories of the abrasive space are analyzed by MATLAB software.The effects of ultrasonic excitation on the speed and acceleration of the tool are analyzed theoretically.The kinematics characteristics of diamond abrasive grains and their interaction with the materials to be removed are described.(3)The morphological changes of quartz glass under the condition of continuous linear load control and depth control are studied by nano-indentation experiment and scratch test.The nano-indentation depth curve and the elastic-plastic-brittle states change of quartz glass and depth,load and acoustic signal curves during these states are obtained.Summarizing the microscopic removal of quartz glass and the critical load and critical cutting depth of elasticplastic and brittle-plastic.(4)The effects of the feed speed,the spindle speed,the cutting width and the depth of the cutting on the surface quality of the machined surface comparing with the traditional face milling are studied.The influence of the ultrasonic amplitude on the actual cutting depth was analyzed theoretically and experimentally from different aspects.