Study on Applying Cavitation in Micro Drilling of Austenite Stainless Steel — Control of Burr in Through Hole Drilling —
Akira Mizobuchi* and Hitoshi Ogawa**
*Institute of Technology and Science, The University of Tokushima, 2-1 Minamijyousanjima-cho, Tokushima 770-8506, Japan
**Tokushima Prefectural Industrial Technology Center, 11-2 Nishibari Saiga-cho, Tokushima 770-8021, Japan
Microdrilling is required to produce nozzles for fiber, fuel etc. A problem arising in microdrilling is the need to remove chips to avoid tool breakage. This paper deals with how cavitation affects machining fluid using ultrasonic vibration for chip control. Thrust force, hole shape and burr formation are observed in drilling austenite stainless steel SUS304 with a through hole 0.1mm in diameter. Cavitation-assisted drilling reduces chip adhesion and burr height while drilling number increases, as compared to conventional drilling. During through-hole drilling, cavitation occurs in a blister generated by machining fluid at the hole exit. The burr height in cavitation-assisted drilling is smaller than that in conventional drilling. Tool life in through-hole drilling is the same as in blind-hole drilling. We studied the effect of cavitation on burr removal using B4C powder.
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