| Popis: |
In this study, AISI D2 and AISI D3 cold work tool steels were drilled by using uncoated HSS and carbide drill bits. The drilling tests were performed on a CNC vertical machining centre at 15, 20, 25 and 30 m/min cutting speeds and 0.06, 0.08, 0.1 and 0.12 mm/rev feed rate without coolant. Maximum cutting force (Fz) and maximum torque values were measured during the drilling process. The effects of cutting speed, feed rate, and drill and workpiece material on the maximum cutting force and torque were investigated. Increasing the feed rate generally lifted the maximum cutting forces up for the test parts. However, the cutting speed did not have a clear effect on the maximum cutting forces. In drilling of AISI D3 cold work tool steel, higher forces were obtained than those obtained in drilling of AISI D2 cold work tool steel. In addition, carbide drill bits led to the lower forces than did HSS drill bits. |
