| 摘要: | 藍寶石係屬高硬脆材料，於進行微孔鑽削加工時，刀具的磨損大且加工後的孔周圍會產生大面積脆性破裂，必須加以克服。本研究是利用超音波振動輔助啄鑽加工方式針對藍寶石材料進行微孔加工之研究，探討各種加工方式與參數如進給速度、啄鑽量、超音波功率與主軸轉速對加工品質特性的影響，加工品質特性包括有微孔入出口之破片面積值、刀具切削刃變化量與實際微孔直徑，並利用光學顯微影像量測儀（OM）、雷射共軛焦掃描顯微鏡（LSCM¬）及掃描式電子顯微鏡（SEM）觀察藍寶石在鑽削後加工微孔的直徑、破片面積值與微孔周圍的破裂形貌。
實驗結果顯示，超音波振動輔助啄鑽加工可排除藍寶石材料於加工過程中切屑和加工產生的廢熱，可有效減少加工中的切削力及加工溫度，降低刀具磨耗，進而延長刀具壽命，而根據實驗結果在進給速度0.15 mm/min、啄鑽量15 μm、超音波功率等級Level 2 (Amplitude：0.23 μm)以及主軸轉速10000rpm時，可得到較佳的入口破片面積1877.852 μm²以及較佳的出口破片面積2505.519 μm²，相較於傳統鑽削方式，入口破片面積值減少了344.53%，而出口破片值減少952.04%，且平均孔徑入出口差異值及切削刃圓角變化量較小，提高了刀具壽命。
;Sapphire is a high hard-brittle material. During micro-hole drilling, the tool wear is enormous, and a large area of brittle fracture will occur around the machined hole. To overcome these problems, this research adopted ultrasonic vibration-assisted pecking drilling of the micro-holes on sapphire. The influence of various processing methods and parameters, such as the feed rate, pecking depth, ultrasonic power, and spindle speed, on the machining qualitaty characteristics were discussed. Machining quality characteristics include the value of the chipping area at the inlet and outlet of the micro-hole, the variation of arc radius of the cutting edge, and the average diameter of micro-hole. Optical microscopy (OM), laser scanning confocal microscopy (LSCM), and scanning electron microscopy (SEM) were used to observe the diameter of the micro-hole, the value of the chipping area, and the fracture morphology of micro-holes in sapphire after drilling.
The experimental results indicate that ultrasonic vibration-assisted pecking drilling could remove waste heat from chipping and machining of sapphire material during machining, which can effectively reduce the cutting force and processing temperature during machining, minimizing tool wear, and therefore, extending tool life. According to the experimental results, a better inlet chipping area of 1877.852 μm² and a better outlet chipping area of 2505.519 μm² were obtained under the feed rate of 0.15 mm/ min, pecking depth of 15 μm, ultrasonic power level of 2 (amplitude: 0.23 μm), and spindle speed of 10000 rpm. Compared with the traditional drilling method, the value of the inlet chipping area was reduced by 344.53%, the value of the outlet chipping area was reduced by 952.04%, and the difference value between the inlet and outlet of the average hole diameter and the change of the cutting edge fillet was smaller, which improves the tool life. |
