雷射輔助陶瓷切削的準穩態熱分析;A Quasi-Steady-State Thermal Analysis for Laser-Assisted Cutting of Ceramics

[[abstract]]本計畫對射輔助陶瓷削進熱分析並以實驗測驗證。射輔助削乃用局部熱源加熱工件，於去除材前提昇工件溫到達能使用傳統刀具削陶瓷的溫，以增進陶瓷去除。在高溫情況，陶瓷的伏強低於破壞強，變形為由脆性轉為延性，能使用單點削刀具以接近屬削的速移除材。本研究發展出一射預熱並由固定進給的刀具削轉動之陶瓷圓柱工件的熱模式。因為削刀具沿軸向以固定距緊跟於移動射束之後，換言之削刀具進給速等於射束移動速，所以這問題能以隨射束或削刀具移動的圓柱座標公式化，因此可視為準穩態問題。這熱模式的解析解被獲得。結果比較於實驗據。射輔助陶瓷削期間的溫場被呈現。進給及射功對陶瓷工件內溫分佈的影響亦被探討。 ;This proposal performed a thermal analysis for laser-assisted cutting of ceramics and the results were verified by an experimental measurement. Laser-assisted cutting can increase ceramics removal rates by utilizing a localized heat source to elevate the workpiece temperature prior to material removal with traditional cutting tool. At high temperatures the yield strength of ceramics can decrease below the fracture strength, changing the material deformation behavior from brittle to ductile and enabling the use of a single point cutting tool to remove material at rates approaching those of metal cutting. A thermal model was developed for the rotary workpiece of ceramics cylinder, which was preheated by a laser and cut by cutting tool with a constant feed rate. Since the cutting tool follows after the moving laser with a fixed distance in an axial direction, i.e., the feed rate of the cutting tool is the same as the moving velocity of the laser, this problem can be formulated in a cylindrical coordinate system that moves with the laser beam or cutting tool and therefore, it is considered as a quasi-steady-state problem. An analytical solution for this thermal model was obtained. The results calculated by this model were compared with the experimental data. The temperature field was presented during laser-assisted cutting of ceramics. The effects of feed rate and laser power on temperature distribution were also discussed in this study[[note]]計畫編號:NSC95-2221-E146-007;研究期間:9508~9607 ;研究經費:533 千