關於鈦合金的超塑性成形研究已經有很長的一段時間，Ti-6Al-4V在這個領域當中，因其具有優越的超塑性與擴散接合的特性，使得它是目前使用最為廣泛的鈦合金超塑性材料。而厚度分布在超塑性成形中，又具有其重要性；當在發生塑性變形時，厚度分布可以提供成形過程中的相關資訊，因此分析厚度分布有其必要性。 本實驗主要研究主題在於長方形盒成形後的厚度分布分析，為了知道如何使得厚度分布均勻一致，將從三個部分著手；分別為文獻資料、試誤法、MARC軟體模擬分析，以獲得其有效成形壓力與時間曲線。而且依照MARC模擬出來之有效成形壓力與時間曲線所吹製出來的實驗，其最大厚度差可以控制在11%以內(不含入模角)。另外將潤滑液改採用石墨液混合氮化硼代替先前所使用的石墨液與氮化硼，可以將最大厚度差由11%下降到4%左右，以改善其厚度分布的均勻性。比較MARC模擬的厚度分布與實驗吹製出來的厚度分布，其最大誤差率約為8%(不含入模角)。簡而言之，我們可以透過MARC精準的預測實驗結果，並且達到節省成本的目的。 Superplastic forming of titanium alloys has been studied popularly for a long time. Ti-6Al-4V has two characteristics, superior superplastic forming and diffusion bonding, which dominate the result in its wide application in titanium alloys. To analyze the distribution of thickness in superplastic forming is significant, because it can provide the information about the process of plastic deformation of Ti-6Al-4V. The main subject is to study on the distribution of thickness of rectangular box. In order to know how to obtain the uniform thickness, it’s necessary to analyze pressure profiles. By adopting two methods, try and error and finite element-MARC, pressure profiles are easily obtained. Besides, we can also get pressure profiles by consulting documentary data. From the result of experiment, it shows the tolerance of thickness is less than 11% when disregarding the factor of die entry radius. The tolerance of thickness can reduce from 11% to 4% when mixture of graphite and boron nitride is substituted for the original lubrication. According to the comparison of distribution of thickness between MARC and experiment, we can get the error rate is less than 8% when disregarding the factor of die entry radius. In a word, we can predict the result of experiment by MARC and save the cost.
