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研究生:謝世峰
研究生(外文):Hsieh, Shy-Feng
論文名稱:鈦鎳鋯與鈦鎳鋁三元系形狀記憶合金之研究
論文名稱(外文):A Study on Ternary Ti-Ni-Zr and Ti-Ni-Al Shape Memory Alloys
指導教授:吳錫侃---
指導教授(外文):Wu Shyi-Kaan
學位類別:博士
校院名稱:國立臺灣大學
系所名稱:材料科學與工程學研究所
學門:工程學門
學類:材料工程學類
論文種類:學術論文
論文出版年:1997
畢業學年度:86
語文別:中文
論文頁數:166
中文關鍵詞:麻田散體相變態包晶反應熱時效冷加工
外文關鍵詞:TiNi形狀記憶合金TiNi Shape Memory AlloysMartensitic transformationPeritectic ReactionThermal AgingCold Working
相關次數:
  • 被引用被引用:2
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本文利用電阻實驗、DSC、X-Ray繞射、EPMA、TEM及內耗實驗等來研究TiNiZr與TiNiAl三
元系形狀記憶合金之麻田散體相變態的性質與行為,及其形狀記憶效應的特性,並同時探
討熱機處理(時效、冷加工、熱循環)對這些合金之影響。其目的在開發能使用在高溫下(1
00℃~400℃)的形狀記憶合金,以及發展更實用的技術。實驗結果顯示Ti50.5-XNi49.5ZrX
及Ti53-XNi47ZrX(X=5~20 at.%)系列合金均具有高溫的形狀記憶效應(SME),且其Ms點可
控制在50℃~350℃之間,而其變態順序均為B2→19''之一階變態。由顯微組織中發現有許
多第二相顆粒[(Ti,Zr)2Ni或λ1相]存在於基地(Ti,Zr)Ni週圍,且經由DTA測試,其λ1相
熔點約在930℃,990℃的吸熱峰則相對應於(Ti,Zr)2Ni相之包晶逆反應,而(Ti,Zr)Ni相
熔點則約在1160℃左右。Ti50.5-XNi49.5ZrX合金經由XRD繞射分析,其結果發現晶格常數
a、c、β角及B19''單位晶胞體積會隨著Zr含量的增加而增加,而b反而減少。Ti30.5Ni49.
5Zr20合金於200℃麻田散體相長時間時效處理,會有麻田散體安定化的現象,時效安定化
的機構認為是麻田散體相的再序化(Reordering)及空孔等缺陷之栓鎖(Pinning)效應所造
成。Ti40.5Ni49.5Zr10合金於內耗試驗發現在麻田散體相變態過程中有鋸齒狀波峰是由於
麻田散體相兄弟晶(Variants)之間的應力誘起調適作用所產生的。富鎳Ti49.5Ni50.13Al0
.37合金於400℃時效過程之變態順序由B2→R→B19''變為B2→R,再變為B2→R→B19'',而T
i47.5Ni50.65Al1.85合金於400℃時效10小時後之變態順序為B2→R之一階變態,主要與Ti
11Ni14析出物有關。兩合金皆具有固溶強化與析出硬化之特性,其硬化速率主要與合金的
Ni/Ti比值及Al的固溶量有關。此外,時效析出強化亦可增進形狀回復能力。富鈦Ti52Ni4
7Al1合金退火處理後之相變態順序為一階B2→B19''麻田散體相之變態;其顯微組織包含基
地及第二相(Ti2Ni),而Al固溶在Ti2Ni量遠比在基地的多,但基地仍因Al的固溶而使變態
溫度降低。本合金經400℃時效處理,其變態溫度會隨時效時間的增加而稍微下降,此乃
因Ti2Ni中固溶的Al原子於時效過程中會向基地擴散,使基地中Al含量稍有增加而強化,
形狀回復率亦因強化而增加。本合金因有Al之固溶而強化及較硬的第二相,故在冷軋延及
熱循環過程中較易導入差排,使Ms變態溫度降低並有助於R相產生。TiNiZr與TiNiAl三元
系形狀記憶合金經熱循環及冷加工之強化亦遵守方程式Ms=To - KΔσy ,其中不同的K值
代表不同強化機構;而材料經退火處理後之原始硬度較高者,其K值亦較大。
A systematic study of ternary TiNiZr and TiNiAl shape memory alloys is conduct
ed in this thesis. The effect of thermal aging and cold rolling are investigat
ed by means of electrical resistivity, differential scanning calorimetry, X-ra
y diffraction, internal friction measurements, EPMA and TEM studies. In order
to understand the effects of various parameters on thermo-mechanical treatment
and improve the relative properties exhibited in TiNiZr and TiNiAl alloys. Ex
perimental results showed that the Ms temperatures of Ti53-XNi47ZrX and Ti50.5
-XNi49.5ZrX alloys can be raised from 50℃ to 350℃ by different amount of Zr
addition. A great number of second phase particles [(Ti,Zr)2Ni, λ1 phase]are
found around (Ti,Zr)Ni grain boundaries. From DTA thermograph of the homogeniz
ed Ti38Ni47Zr15 alloy, the peak at 930℃ is associated with the solid ←→ liq
uid transition of λ1 phase, another peak at 990℃ is associated with the reve
rse peritectic transformation of (Ti,Zr)2Ni→(Ti,Zr)Ni+liq. and the other one
at 1160℃ is the dissolution of (Ti,Zr)Ni→liquid. From XRD diffraction result
s, lattice parameters a, c, monoclinic angle β and unit cell volume V increas
e, but lattice parameter b decreases, with increasing Zr content in Ti50.5-XNi
49.5ZrX alloys. The martensite stabilization was found to occur during the 200
℃ aging in a Ti30.5Ni49.5Zr20 alloy. The mechnaism for the thermal-induced ma
rtensite stabilization is closely related to martensite reordering and pinning
effect in martensite induced by defects. The Ni-rich ternary Ti47.5Ni50.65Al1
.85 and Ti49.5Ni50.13Al0.37 alloys aged at 400℃ can exhibit different transfo
rmation sequence due to the Ms temperature being deeply depressed by the coher
ent stress of Ti11Ni14 precipitates. The hardening effects of Ti47.5Ni50.65Al1
.85 alloy are obvious and much higher than those of Ti49.5Ni50.13Al0.37 alloy
due to the former one having the larger Ni/Ti ratio and a higher Al solute in
its matrix. These aged TiNiAl alloys exhibit very good shape memory effects, i
n which the maximal shape recovery occurs at the peak of hardness. The Ti52Ni4
7Al1 alloy has 16% volume fraction Ti2Ni particles in the B2 matrix with Ti2Ni
particles having a higher Al content than the B2 matrix. Transformation tempe
ratures M* and A* of this alloy are lower than those of the Ti51Ni49 alloy due
to the solid solution of the Al atoms. M* and A* decrease with increasing agi
ng time at 400℃ because the Al atoms diffuse slightly from the Ti2Ni to the B
2 matrix. This alloy has a higher inherent hardness of the matrix and much mor
e harder Ti2Ni particles due to the solid solution of the Al atoms. This also
causes the R-phase transformation to be more easily promoted by both cold roll
ing and thermal cycling in this alloy. The strengthening effects of cold rolli
ng and thermal cycling on the M*(Ms) temperature of TiNiZr and TiNiAl alloys f
ollow the expression Ms = To - KΔσy , in which K values are affected by diff
erent strengthening processes. It is found that the higher the inherent hardne
ss of the TiNi and TiNiX alloys, the higher the K values they have.
封面
摘要
Summary
I 、前言
II、前人研究
一、高速公路之植栽
二、樹種評估
三、景觀美質評估
四、維護管理評估
III、研考地區概況
一、氣象
二、地形
三、人工植栽
四、自然入侵植群
五、維護管理
六、火燒
IV、研究項目與方法
一、道路沿線景觀美質評估
二、評估樹種之選定
三、樹種景觀美質評估
四、樹種維護管理評估
五、樹種兼顧景觀美質與維護管理之整合
V 、結果與討論
一、道路沿線之景觀美質
二、樹種之景觀美質
三、樹種之維護管理
四、樹種兼顧景觀美質與維護管理
VI、結論與建議
VII、引用文獻
VIII、附錄
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