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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/2232

    Title: Ti-6Al-4V之超塑性成形製程模擬與分析;Superplastic Forming Processes Simulation and Analysis of Ti-6Al-4V Alloy
    Authors: 王善民;Shan-Min Wang
    Contributors: 機械工程研究所
    Keywords: 有限元素法;超塑性成形;Ti-6Al-4V;Ti-6Al-4V;SPF;FEM
    Date: 2003-06-19
    Issue Date: 2009-09-21 11:41:28 (UTC+8)
    Publisher: 國立中央大學圖書館
    Abstract: 超塑性吹氣成形是利用某些經特殊處理過使其具有超塑性能力的合金材料,在特殊的加工條件下,藉由其成形只需較低流變應力的特性,來完成具有複雜外形或尖銳角的成品。為了滿足成形之應變速率能維持在目標值附近,以達到最佳均勻變形之能力,並探討模具幾何性質、材料和邊界性質對成形壓力與時間和成品最終厚度分布之影響,本文使用有限元套裝軟體MARC並結合實驗來探討與分析Ti-6Al-4V鈑材之超塑性成形製程。在建立最佳之分析模式方面,本文分別使用了不同的維度和元素來分析比較並探討其中之差異。結果顯示三維薄膜元素模擬之結果與其實驗間之數據的誤差值低於10%。由分析的結果可以得知,以下七項可使成品有較佳之厚度分布: (1) 改變鈑材局部厚度 (2) 增加潤滑性 (3) 增加拔模角角度 (4) 加大入模角和下導角半徑 (5) 晶粒細化 (6) 降低寬深比 (7) 增加鈑材之挾持距離 在相同應變速率的前提下,以下五點可以減少成形之時間: (1) 晶粒細化 (2) 增加拔模角角度 (3) 加大入模角和下導角半徑 (4) 增加潤滑度 (5) 降低寬深比 Superplastic blow forming is that employs the some alloy materials of superplasticity under specially working environment by hot machine method etc….It uses the exceptional property of low stress to manufacture components of various product with complex curved surface or keen angle surface. In order to hold the excellent capability of uniform deform in the forming process, the strain rate has to be kept near the optimum target. In addition, to affect the geometric parameter of rectangle-boxed closed die, material and boundary properties are also been discussed with forming pressure vs. time history and final thickness distribution. This paper uses a combined commercial finite element program-MARC and experiment to analysis the superplatic forming processes of Ti-6Al-4V sheet. In the processes, using different dimension models and different element modals of simulation as numerical values to experiment, they compared what differences. Found the three-dimension element modal is the most accurate and its tolerance is less than 10%. According to the analysis results, below are some methods which promote uniform of final thickness distribution: (1) to change thickness of some locals (2) increase the lubrication between die and sheet (3) increase entry and up radius (4) increase draft angle (5) grain size refine (6) decrease aspect ratio Under the principle of constant strain rate, below are some methods which reduces forming time: (1) grain size refine (2) increase draft angle (3) increase entry and up radius (4) increase the lubrication between die and sheet (5) decrease aspect ratio
    Appears in Collections:[機械工程研究所] 博碩士論文

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