Effects of Surface Modifications on the High-Temperature Behavior of Ti-15-3 Alloy

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基本資料

Project title

Code/計畫編號

NSC98-2221-E019-007

Translated Name/計畫中文名

Ti-15-3合金應用研究---表面改質效應對Ti-15-3合金高溫腐蝕行為之研究

Project Coordinator/計畫主持人

Wu Kai

Funding Organization/主管機關

National Science and Technology Council

Department/Unit

Department of Optoelectronics and Materials Technology

Website

https://www.grb.gov.tw/search/planDetail?id=1881189

Year

2009

Start date/計畫起

01-08-2009

Expected Completion/計畫迄

31-07-2010

Bugetid/研究經費

1027千元

ResearchField/研究領域

材料科技

本研究為【Ti-15-3 合金應用研究】整合型計畫之子計劃二，擬以三年為一期，主要探討『表面改質效應對Ti-15-3 合金高溫腐蝕行為之研究』，茲將各年度之研究要點分述如下： (1) 第一年度將評估表面改質效應（鍍鎳滲鋁/鉻、粉浴鋁化、或鋁/鉻化濺鍍）對高強度 Ti-15V-3Cr-3Al-3Sn 合金(以下簡稱Ti-15-3）在含純氧、空氣及氬/氧混合氣條件下高溫氧化的影響，藉由適當的表面改質方式來提升Ti-15-3 的抗氧化能力；預期的溫度效應將細分為恆溫（範圍在 600-900oC）及熱循環（即連續多次升/降溫方式）兩大類，藉以探討不同表面改質及溫度效應下Ti-15-3 之氧化動力學及反應機構。全程實驗是在高靈敏度之熱重分析儀(TGA)或石英彈簧(高溫管式爐)中進行，以連續監測試片經腐蝕反應後所得的相對重量變化量，經轉換並計算合金之氧化動力學數據；同時，輔以白金指標實驗來判斷氧化反應機制，並借助X-光繞射(XRD)、金相光學(OM)、掃描電鏡 (SEM)、電子微探儀(EPMA)、電子能譜儀(AES)及穿透電鏡(TEM)之分析，以瞭解合金氧化物的相組成、成分分布及反應界面之差異性。 (2) 第二年度擬將配合其他子計畫之第一年研究成果及經驗，探討顯微結構變化（如：子計畫一之晶粒細化以及子計畫三、四在銲件之晶粒粗化）對第一年度所建立表面改質處理之Ti-15-3 母材及銲件的氧化行為影響；同時也評估含水蒸汽效應對表面改質後的鈦合金在空氣氧化之影響（測試方法同第一年），其結果將與第一年度之成果相互比較，瞭解不同表面改質方式及合金元素對Ti-15-3 合金抗氧化之差異性，並有系統地建構Ti-15-3 合金高溫氧化實驗數據之資料庫。 (3) 第三年度擬將彙整前二年本子計劃之研究成果，並配合其他子計畫在二年內之研究成果及經驗（相似於前二年之方式），來評估最佳的顯微結構及表面改質處理方式對Ti-15-3 母材及銲件在前兩年度所建立的不同腐蝕環境之影響（方法同第一年），同時，也評估試片表面披覆Na2SO4/NaCl（不同配比之熱腐蝕源）對表面改質後的鈦合金在空氣之熱腐蝕影響（方法亦同第一年），比較腐蝕反應之差異性，其結果將與前兩年度之成果相互比較，確立完整的鈦合金高溫腐蝕實驗數據；同時，透過定期與其他子計畫之心得交換，找出最佳的合金材質、表面改質組成及顯微組織參數，建立整體的鈦合金之應用資料庫，一方面將研究成果發表於國際知名期刊，彰顯本研究的知名度，另外也將本研究成果直接提供相關業界運用，促進Ti-15-3 合金發展之應用價值。The research proposal of ""Effects of surface modifications on the high-temperature behavior of Ti-15-3 alloy"" is proposed, which is a part of the 3-year group-proposal of "" Research on the applications of Ti-15-3 alloy” (in Proposal Part II). The main goals of this research are described yearly as follows: (1) In the first year, the effects of proper surface-modifications (i.e. containing Ni-plating plus Al/Cr dipping, Al/Cr pack-cementations, or Al-/Cr- sputtering) on the high-temperature oxidation of Ti-15V-3Cr-3Al-3Sn (Ti-15-3) are evaluated over the temperature range of 600-900oC in various O2-containing environments (containing pure oxygen, air, and Ar-O2 mixed gases). The results will be compared to those of the untreated base-alloy to evaluate the corrosion resistance of the various modifications. Both isothermal- and cyclic-oxidation conditions will also be explored to study the possible difference in oxidation kinetics and reaction mechanisms of the alloys with or without surface-modifications. The corrosion tests of samples are performed by continuously measuring mass-change data through thermo-gravimetric analyzer (TGA) or the tube furnace with quartz springs. The corrosion data are converted and compared to scale thickness obtained metallurgically. Pt-marker studies are performed to determine reaction mechanisms of the alloys, and the phase constitution and spatial distribution of the scales as well as the microstructural characterization of the scale/substrate interface will be investigated by X-ray diffraction (XRD), OM, SEM, EPMA, AES, and TEM analyses. (2) In the second year, based on the results of other sub-proposals in the first year (such as the microstructure refining in Part I and the grain coarsening in parts III and IV), the effects of water vapor on the oxidation behavior of the Ti-15-3 substrate and welded alloys will be evaluated in the similar procedure of the first year. This is done to establish the fundamental database for the high-temperature oxidation behavior of the Ti-15-3 alloy. In addition, the results of the possible difference between grain-refining and -coarsening alloys will be studied and compared to those obtained in the first year. The roles of alloying elements and surface modifications on the oxidation resistance of the Ti-15-3 alloy will be discussed in order to build up the database for the high-temperature corrosion and prevention. (3) In the third year, based on the results of other sub-proposals in the first and second years (as indicated in (1) and (2)), the effects of the samples deposited by various ratios of Na2SO4/NaCl mixed salts will also be evaluated, as the similar procedure of (1). The results of this year will be compared to those of the previous two years. All group applicants will share their experiences with others for the purposes of obtaining the best high-strength Ti-15-3 alloy combined with excellent surface-modifications and grain structure after the 3-year research study. The final goal of this research is not only to submit all the individual results to the international journals for publication, but also to wholly establish the systematically high-performance Ti-15-3 alloy database for industrial applications.

Keyword(s)

表面改質
Ti-15-3 合金
高溫氧化
熱腐蝕
腐蝕動力學
反應機構
surface-modifications
Ti-15-3 alloy
high-temperature oxidation
hot corrosion
corrosion kinetics
reaction mechanisms

DSpace CRIS

Effects of Surface Modifications on the High-Temperature Behavior of Ti-15-3 Alloy

基本資料

Description