Study On Ultrasonic Vibration Assistant Sawing Mechanism For Alumina Ceramics

With the application of hard and brittle materials related to all areas of science andtechnology in everyday life, as a new engineering material, engineering ceramics hasbeen paid more attention. However, due to high oxidation ceramic hardness,brittleness, low efficiency of conventional sawing method, low processing surfaceaccuracy, prone to cracking and chipping slit edges, its further application is limited.As a special processing machining, ultrasonic vibration assisted machining hasbecome an effective way to machining hard and brittle materials such as ceramics.Therefore, this paper studied the mechanism of ultrasonic vibration assisted sawing,laying foundation for subsequent ultrasonic vibration assisted cutting processapplication. The main results are shown as following:1. In this paper, the ultrasonic vibration and general diamond blades sawing werecombined. This paper presents a set of ultrasonic vibration assisted cutting systemwhich makes the workpiece exciting.2.This paper explored interaction mechanisms between blade and workpiece,founding that there are a variety of forms in ultrasonic vibration assisted cuttingprocess, which different from ordinary sawing, and these forms is to explain thephenomenon of ultrasonic cutting process. The effects of cutting parameters on theultrasonic vibration assisted sawing force were investigated, the results showed thatas the cutting speed and cutting depth increase, cutting force increases, but whenblade speed increases, cutting force reduces. If the ultrasonic vibrations wasintroduced, the cutting force, the cutting force ratio and sawing specific energy isreduced. With the cutting depth, feed rate increases and speed decreases, the effectof reducing the cutting force is more obvious.3. Based on indentation fracture mechanics, ultrasonic vibration assisted cuttingcritical cutting depth was analyzed, ultrasonic vibration assisted cutting single grainmaximum cutting depth is greater than ordinary sawing. Under the same cuttingparameters, in the machining of ultrasonic vibration sawing, the brittleness removal ratio of the workpiece trench bottom is greater than ordinary sawing, which isbeneficial to subsequent material removal, and its material removal is better thanordinary sawing. The roughness of the workpiece sawing side surface is lower thannormal sawing. In the same sawing side quality, the efficiency of ultrasonicvibration sawing is higher than ordinary sawing.4.During the blade wearing experiment, because of ultrasonic vibration impact,the forms of blade shape mainly present micro-crushing which forms numerouscutting edge, binders removal rate increasing, the grit abrasive blade heightincreasing and the new edges breaking out in time. With the total material removalincreasing, the sawing force and force ration of ultrasonic vibration assisted sawingrise slower than normal sawing, which performs good self-sharpening.