Study on Rotary Ultrasonic Machining and its Predictive Model of Cutting Force on Dental Zirconia Ceramics

牙科氧化鋯陶瓷的旋轉超聲加工及其切削力預測模型研究

鄭侃(Kan Zheng) ； 肖行誌(Xing-Zhi Xiao) ； 董松(Song Dong) ； 廖文和(Wen-He Liao) ； 劉世豪(Shi-Hao Liu)

《中國機械工程學刊》 41卷2期 (2020/04) Pp. 121-130

摘要

Based on the disadvantages existed in the machining of zirconia ceramic crowns, such as complicated process of sintering and difficulties in controlling shrinkage rate, the method of rotary ultrasonic machining (RUM) in sintered zirconia ceramic crowns has been proposed. The experiments of RUM have been conducted in terms of machining requirements and the failure mode of zirconia ceramic crowns. According to the influences of cutting parameters on machining qualities in different machining methods, the effect mechanism of cutting force on the labial margin edge quality and the surface damage of crowns have been revealed. Therefore, in order to control the labial margin edge quality and the surface damage effectively, a cutting force predictive model has been built based on the partial least squares (PLS) during RUM. The average error between experimental results and predictive results is only 8.23%, which indicates that the model can be applied to guide the RUM of dental zirconia ceramics for dentists.

關鍵字

Zirconia ceramics ； dental restorations ； rotary ultrasonic machining ； partial least squares ； cutting force predictive model

並列摘要

考慮到氧化鋯陶瓷牙冠現有制造工藝存在二次燒結加工工藝復雜、收縮率難以控制等問題，提出了采用旋轉超聲加工完全燒結氧化鋯陶瓷牙冠的方法。針對氧化鋯陶瓷牙冠的制造要求和失效模式，開展了旋轉超聲加工實驗研究。通過對比不同加工方法和切削參數對氧化鋯陶瓷工件加工質量的影響程度，闡明了超聲振動輔助下，切削力對牙冠頸緣線棱邊質量及表面損傷的作用機理。因此，為了實現對牙冠頸緣線棱邊質量和加工表面損傷的控制，以13組實驗數據為樣本，建立了壹種基於偏最小二乘法的旋轉超聲加工牙科氧化鋯陶瓷的切削力預測模型。將切削力的預測值與實驗值進行對比表明，所構建的切削力預測模型的平均誤差僅為8.23%，體現了良好的預測精度。