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題 名 | The Forming Behavior and Post-Form Properties of Superplastic 8090 Al Thin Sheets=8090鋁合金薄板之超塑成形與成形後性質 |
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作 者 | 陳宗榮; 黃志青; | 書刊名 | 材料科學 |
卷 期 | 25:1 1993.03[民82.03] |
頁 次 | 頁34-49 |
分類號 | 440.39 |
關鍵詞 | 8090鋁合金薄板; 超塑成形; |
語 文 | 英文(English) |
中文摘要 | 本實驗是針對航空用8090鋁鋰合金,利用自行設計裝配之氣吹成形機, 進行超塑成形性研究。觀察重點為各成形因子之影響,包含加壓曲線、成形溫度、 成形深度、潤滑作用、和成形後性質。超塑成形是利用一底部可調整之封閉式模 具,以一簡化之電腦模擬程式所得之升壓曲線來氣吹成形,在成形深度/直徑比 為1/6,1/4與1/3時運用良好。另以石墨和氮化硼兩種不同之潤滑劑,發現氮化棚可 得到較均勻之厚度分佈。成形件之最大形變或最小厚度發生於下曲角靠底部之 處,並非下曲角正中心處。實驗中並自成形後之試片底部截取拉伸試片,顯示其 機械性質隨超塑成形變形量之增加而降低,但使用不同之潤滑劑對試片成形後之 機械性質並無顯著之影響。 |
英文摘要 | Super plastic forming (SPF) of an aircraft-used 8090 A1-Li thin sheet has been conducted. Emphasis was placed on the various forming parameters, such as gas pressure input, forming temperature, height/diameter (h/D) ratio, lubricants, and post-forming properties. The pressure profiles simulated from a modified computer program were found to be effective for SPF in the close-die to h/D ratios of 1/6, 1/4 and 1/3. This pressure profile is optimized considering the effects of decreasing strain rate, rate sensitivity, and work hardening contributions. The maximum meridional and circumferential strains and the minimum thickness were found to be located at the bottom side of the corner for specimens SPFed from the close-die with a h/D ratio less than 1/2. With the lower value of strain rate sensitivity and without the application of back pressure, the minimum thickness at h/D= 1/3 is only 35 of the original thickness. The thickness distributions can be improved using lubricants such as BN. The post-form properties were examined in terms of tensile tests, cavitation and grain structure, and were found to be increasingly degraded with increasing SPF strain. |
本系統中英文摘要資訊取自各篇刊載內容。