| 摘要: | 本論文是以溶膠-凝膠法來制備鋯鈦酸鉛(PZT)陶瓷薄膜，將制備好的PZT 溶膠凝膠塗佈在不同金屬基材上(鋁、不鏽鋼、銅及鈦)，在塗佈完成後施以不同極化條件，並將所得薄膜利用X 繞射分析儀(X-Ray Diffraction, XRD)進行結晶分析，以及以掃描式電子顯微鏡(Scanning Electron Microscopy, SEM)觀察其微結構，接著使用精密阻抗分析儀量測其介電常數、介電損耗，且探討PZT 膜的特性。將制備好的PZT 膜應用在聚丙烯( Polyproylene, PP)塑膠板熱壓成型過程，進行非破壞非侵入式的即時流程檢測。
實驗結果顯示使用不同金屬基材所制備完成的PZT 膜，從XRD 來觀察其鈣鈦礦相結晶，以塗佈在鋁跟鈦基材上有比較佳之結晶向，而塗佈在不鏽鋼跟銅基材上則較次之，若是將此結晶相與熱膨脹係數相比較，可發現鋁及鈦基材的熱膨脹係數與PZT 陶瓷膜的較相近，反之不鏽鋼及鋁的則有較大差別，由此可知金屬基材的膨脹係數與PZT 膜的相近者，可得到較佳之結晶向；接著比較其介電常數跟介電損耗時，實驗結果也呈現類似的趨勢。另外針對在極化過程中所施加的極化電壓進行探討發現施加較大的極化電壓時，會得到較好的鈣鈦礦相及電性的常數。
將所制備的PZT 膜固定在模具上，接著將PP 塑膠板放入模具內，進行閉合、加熱、加壓、保壓、冷卻、脫模取出成品之過程，對此過程進行超音波即時監測，觀察模具內塑膠熔解、保溫、保壓及冷卻的變化情形。結果顯示PP 塑膠板內的超音波速度會隨著溫度的變化而改變，塑膠板的固/液相變化可以由超音波速度觀察到，並且發現在冷卻過程當溫度降到85℃以下時超音波速度進入一個穩定狀態，由此可知PP 塑膠板在此時已經固化，不再需要額外的冷卻可以打開模具取出成品，因而縮短製造流程時間節省能源消
耗，並達到製程條件最佳化之目的。
因此，本論文探討，在PZT 膜制備過程當中，基材及極化電壓對膜特性的影響，並且將制備的PZT 膜應用於PP 塑膠板熱壓成型過程的即時檢測，對熱壓成型過程的相變化進行監測，以達到縮短製程，減少能源消耗，以及最佳化程序的目的。
A sol-gel method was utilized to fabricate the ceramic PbZrxTi1-xO3 (PZT) film in this thesis.The prepared PZT sol-gel was coated on various metal substrates, including copper (Cu), alumina(Al2O3), stainless steel (SS) and titanium (Ti). After thermal treatment, the films were polarizedunder various conditions. The characteristics of the fabricated films, such as crystallization, microstructure, dielectric constant and loss, had been measured by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and LCR meter. The fabricated PZT film was attached on themold of hot embossing machine for real-time diagnosis of polymer hot embossing process nondestructively and non-intrusively.
From the results of experiments, the intensities of PZT (110) phases of films on the Al2O3 and titanium Ti substrates were better than those on the Cu and SS substrates. Comparing with the thermal expansion coefficients of these metal substrates, the thermal expansion coefficients of Al2O3 and Ti substrates were closer than other two substrates. It indicated that the metal substrates with thermal expansion coefficients similar with PZT film would result in the better crystallization. When compared with their dielectric constants and losses, the tendency was similar. For investigating the voltage effect during the poling process, the applied higher voltage would result in the better crystallization and dielectric characteristics of films.
The fabricated PZT film was attached on the mold of hot embossing machine for carrying out the processes of mold closing, heating, pressing, holding, cooling and mold detaching. The ultrasonic technique was adapted to monitor the melting, holding and cooling processes of polymer plate (Polyproylene, PP) inside the mold. The results indicated that the ultrasonic velocity of polymer would vary with the mold temperature, and the phase change of polymer plate between
solid and liquid would be monitored by ultrasonic velocity. When the mold temperature lowered than 85℃, the ultrasonic velocity entered into a stable state, indicating that the polymer plate was already solidified and further cooling may not be necessary. From this information, the hot embossing process could be reduced to lower down the cost and reach the process optimization.
In this thesis, the effects of metal substrates and polling voltage on the characteristics of the PZT films during the fabricating process were investigated. The fabricated PZT film was applied on the real-time diagnosis of polymer hot embossing process for monitoring the phase change of polymer plate to reduce the cycle time, lower down the cost and optimize process. |
