Influence of diamond wiresaw excited by transverse ultrasonic vibration on cutting force and critical cutting depth of hard and brittle materials

Abstract

The hard and brittle materials, such as SiC, Ge and Si, are very difficult to cut at ductile mode by conventional machining, because of a extremely small critical cutting depth. Influence of diamond wiresaw excited by transverse ultrasonic vibration on cutting force and critical cutting depth of hard and brittle materials is crucial. Based on analyzing forced vibration of wiresaw, the required conditions that meet the hard and brittle materials rotary cutting at a point in flexible mode by transversely vibrating diamond wiresaw is analyzed and obtained. The characteristic function is used to describe the cutting states of hard and brittle materials cut by transversely vibrating wiresaw. Applying grinding theory, the mechanics model of hard and brittle materials cut by single diamond abrasive particle is established. The formula calculating critical cutting depth of hard and brittle materials cut by transversely vibrating diamond wiresaw is deduced. Comparative experiment of cutting SiC crystals by ultrasonic vibration wiresaw and conventional wiresaw is conducted. The experimental result shows that the cutting force in vibrating wiresaw cutting decreases 22.4%~64.2% than that in conventional wiresaw cutting under the same machining conditions. The critical cutting depth of SiC monocrystals in vibrating wiresaw cutting is double than that in conventional wiresaw cutting. The surface roughness of wafers is improved obviously. Experimental results is consistency with the theoretical analysis.