鈦鎳基形狀記憶合金變態及機械性能之研究

Transformation Behavior and Mechanical Properties of TiNi-Based Shape Memory Alloys

林耿華(Keng-Hua Lin)

指導教授 ： 吳錫侃

國立臺灣大學/工學院/材料科學與工程學研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.00565

摘要

本研究對不同熱機處理條件的Ti49.3Ni50.7 及 Ti50Ni48.5 Fe1.5 形狀記憶合金分別量測其形狀記憶效應及超彈性。研究結果顯示，熱機處理所導致的強化效應及微結構改變對於鈦鎳形狀記憶合金的機械性能有顯著的影響。除此之外，合金的織構亦是影響其機械性能的主因。因此，為了解織構的影響，本研究以晶格變形理論(Lattice Deformation Theory)來計算合金的理論可回復應變量。在本研究的所有試片中，經30%冷軋延及300℃ 100小時時效處理的Ti49.3Ni50.7合金具有最高的強化效果，然而，具有最優良的形狀記憶效應及超彈性的卻是經300℃ 100小時時效處理的Ti49.3Ni50.7合金。經300℃ 100小時時效處理的Ti49.3Ni50.7合金之所以具備優良的機械性能和其擁有優選方位的織構、高強度的基材及有利形狀回復之內在缺陷(Ti3Ni4析出物)有關。除了試片間機械性能的比較外，試片在軋延方向及其垂直方向之機械性能關係亦是本研究討論的另一重點。

關鍵字

鈦鎳形狀記憶合金 ； 形狀記憶效應 ； 超彈性 ； 織構 ； 晶格變形理論

並列摘要

Shape memory effects (SME) and superelasticity (PE) of Ti49.3Ni50.7 and Ti50Ni48.5 Fe1.5 shape memory alloys (SMAs) with different thermomechanical treatments are measured in the present study. Strengthening effect and microstructural change generated by thermomechanical treatments lead to large effects on the mechanical properties of TiNi SMAs. In addition, texture is another crucial factor affecting these properties. Therefore, theoretical recoverable strains are calculated from modified Lattice Deformation Theory in order to comprehend the effects of textures. From the experimental results, Ti49.3Ni50.7 sample cold-rolled to 30% reduction and aged at 300℃ for 100h possesses the highest strengthening effect among all samples. However, it is Ti49.3Ni50.7 sample aged at 300℃ for 100h that acquires the highest SME and PE since it possesses the most favorable textures, high strength of matrix, and beneficial internal defects (Ti3Ni4 precipitates). In addition, the relations of mechanical properties along rolling direction and transverse direction of samples with different thermomechanical treatments are also discussed.

並列關鍵字

TiNi shape memory alloys ； shape memory effect (SME) ； superelasticity (PE) ； texture ； Lattice Deformation Theory

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