2011-01-012024-05-14https://scholars.lib.ntu.edu.tw/handle/123456789/658944摘要：本計畫研究極輕質之高制振能鎂合金，選擇Mg-xLi合金(x &#8805; 14wt.%)使其比重能 &#8804; 1.42 g/cm3，達到極輕質之目標。此等極輕質鎂鋰合金將借由動力機械分析儀(DMA)來探討其制振能tanδ的大小，以瞭解合金之組成、加工/時效等熱(機)處理對其制振能力大小的影響，並由實驗之結果探討整理出在常溫附近tanδ能大於0.02之高制振能極輕質鎂合金，且合金之強度能在110MPa以上。由於Mg-xLi (x &#8805; 14wt.%)鎂合金主要為β相(BCC結構)，加工性較一般鎂合金之α相(HCP結構)來得佳，也因而預期其P1峰及P2峰會存在並影響Mg-xLi鎂合金之制振能大小。本計畫擬選擇Mg-14wt.%Li及Mg-17wt.%Li兩種極輕質鎂合金，研究在軋延/時效後之制振能的大小，以作為極輕質高制振能鎂合金設計應用時之參考。<br> Abstract: The aim of this study is focused on the investigation of extra-light magnesium alloys. Mg-xLi alloys with x &#8805; 14wt.% are selected and their specific weight is asked to be lower than 1.42 g/cm3. These selected alloys will be studied their damping capacity tanδ by dynamic mechanical analyser (DMA) tests. The damping properties of these selected alloys affected by alloy’s composition, deformation methods, heat treatment, etc. will be studied and experimental results of tanδ values will be discussed. From testing results, the qualified high damping Mg-xLi alloys which have their tanδ value higher than 0.02 will be found out. The tanδ curve vs. temperature of Mg-xLi alloys can exhibit the properties of P&not;1 and P2 peaks and these properties will affect the alloys’ damping capacities. In this study, Mg-14wt.%Li and Mg-17wt.%Li alloys will be selected to study their damping capacities. These extra-light Mg-xLi alloys have β-phase (BCC structure) which exhibits much better workability than α-phase (HCP structure) of the common magnesium alloys. Damping Characteristics of rolled/aged Mg-xLi (x &#8805; 14wt.%) alloys with tanδ&#8805; 0.02 will be investigated and their tensile strengths have &#8805; 110MPa. The outcoming results of this study will help the damping application of extra-light Mg-xLi alloys in the future.鎂鋰合金極輕質合金制振能動力機械分析儀tanδ值Mg-Li alloysextra-light alloysdamping capacitydynamic mechanical analysis (DMA)tanδ value