Studies to Improve the Material Removal Rate in Ultrasonic Osteotomy
Date Issued
2011
Date
2011
Author(s)
Lai, Cheng-Yu
Abstract
The aim of this research is to increase the material removal rate (MRR) in ultrasonic osteotomy. According to the basic cutting theory, MRR can be increased by decreasing the specific cutting energy or by increasing the cutting power.
For the same work material, the specific cutting energy is mainly affected by the geometrical shape of the cutting tip, including the number of the teeth and the geometrical shape of the teeth. The Taguchi method was used to find the better geometrical shape of the cutting tip compared with the tips in clinical usage now. The highest MRR was found in this experiment for the 5 teeth cutting tip with 0∘rake angle、15 ∘inclination angle and 40∘chamfer angle of each tooth.
Three stainless steel cutting tips with different coefficients of friction were used in the experiment to increase cutting power, and thus MRR. They are uncoated, TiN-coated and DLC-coated, the coefficients of friction are about 0.5, 0.4 and 0.1 respectively. Under the mode of 50 the MRRs for the uncoated tip, TiN-coated tip, and DLC-coated tip are 0.149 mm3/s, 0.153 mm3/s and 0.165 mm3/s. Less power was consumed in overcoming the friction between the tip and side wall of the groove for the lower coefficient of friction cutting tip. This leads to a larger power left for cutting under the same power provided by the hand-piece. As a result MRR is higher.
In base of the experimental results above, a DLC-coated 5 teeth cutting tip with 0∘ rake angle、15∘inclination angle and 40∘chamfer angle of each tooth was proposed. The MRR of this cutting tip was expected to reach 0.49 mm3/s, which was 3.8 times larger than the tip in clinical usage now.
Subjects
ultrasonic osteotomy
material removal rate
cutting power
specific cutting energy
coated cutting tips
Type
thesis
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