ความสัมพันธ์ระหว่างสัญญาณอะคูสติกกับการสึกหรอของดอกสว่านในเหล็กกล้า SS400 / ดนุชา จันทะยาน = A relationship between acoustic signal and drill bit wear in SS400 steel / Danucha Chantayanee
The objective of this research is to study a relationship between acoustic signal and drill bit wear in the SS400 steel. The experiment was conducted at 2 cutting speeds : 450 and 750 rpm and at 2 feed rates : 0.08 and 0.2 mm/rev. Each cutting conditions was experimented with 3 high speed twist drills and drilled 1600 holes on 15 mm thick SS400 steel. The acoustic signal was analyzed in term of Energy, Count, and Hit parameters to correlate with the drill wear. In addition, the experiment was also conducted on the input power measurement at 3 cutting speeds : 280, 450, and 750 rpm and 3 feed rates : 0.08, 0.12, and 0.2 mm/rev using one drill for each conditions. The power measurement complemented the relationship between acoustic signal and drill bit wear. The results showed that Energy and Count gradually and linearly increased as drill wear increased. The signal went up exponentially after the drill was chipped and severely worn. Hit parameter was not correlated well with wear. Due to high variation of acoustic signal, it might not suitable for monitoring drill bit wear. However, acoustic signal might be used to detect chipping of drill bit because of its high sensitivity. The input power was less fluctuating and correlated linearly with the drill wear. The power could be used to monitor the drill bit wear and to detect chipping of the drill.