鈦鎳銅形狀記憶合金與鋯基非晶質合金 低頻制振能之研究

Abstract

本研究針對鈦鎳銅三元形狀記憶合金與鋯基非晶質合金Zr55Al10Ni5Cu30之制振能進行探討。對Ti50Ni35Cu15及Ti51Ni41Cu8形狀記憶合金而言，其變態峰之阻尼值在頻率1Hz，昇降溫速率為3℃/min時，均可達到tanδ0.05以上；但如保持恆溫30分鐘以上，則其阻尼值則會大幅下降，降幅可達82%以上。而其弛豫峰的阻尼值則不會因持溫而大幅下降，且其阻尼值會隨振幅增加而上昇，兩者呈自然指數成長關係。鋯基非晶質合金之制振能雖較鈦鎳銅形狀記憶合金為低，但強度高，如增大其振幅，亦可使其阻尼值上昇，且振幅與其阻尼值亦呈自然指數成長關係。充氫處理對厚度較薄之鋯基非晶質合金制振能有明顯改善，在100mA/mm2之電流密度下充氫2小時，可使薄帶鋯基非晶質合金在頻率1Hz下，昇速溫速率為3℃/min時之tanδ值大於0.01，但較厚之鋯基非晶質合金則無法有明顯改善，其原因可能為厚度對氫原子擴散至試片內部之差異所導致。

Abstract Ren-Jay Hieh This study focused on the damping capacity of TiNiCu ternary shape memory alloys and of Zr-based amorphous alloys, Zr55Al10Ni5Cu30. The damping values, tanδ, at transient peaks of Ti50Ni35Cu15 and Ti51Ni41Cu8 are both over 0.05 at cooling rate of 3℃/min with frequency 1Hz; after keeping the peak temperature for 30mins and above, the tanδ values of Ti50Ni35Cu15 and Ti51Ni41Cu8 are both descends over 82%. On the other hand, the tanδ values at relaxation peaks don’t drops dramatically after keeping peak temperature, however, they ascends with increasing amplitude. Comparing to TiNiCu shape memory alloys, Zr-based amorphous alloys have lower damping capacity but higher strength, However, its tanδ values increase with larger amplitude. Hydrogenation improves the damping capacity of Zr-based amorphous alloys with thinner thickness remarkably, the tanδ value at cooling rate of 3℃/min with frequency 1Hz exceeds 0.01 after hydrogenation under 100mA/mm2 current density for 2 hrs, but hydrogenation can’t improve the damping capacity of Zr-based amorphous alloys with higher thickness as well, it might due to the difference of H atoms diffusing into specimen result from the different thickness.