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Please use this identifier to cite or link to this item: http://ntour.ntou.edu.tw:8080/ir/handle/987654321/34295

Title: 奈米侷限相變化-子計畫四:奈米侷限下陶瓷相變行為研究
Phase Transformation Study of Zro2 Ceramic Material under Nanoconfiment
Authors: 黃榮潭
Contributors: NTOU:Institute of Materials Engineering
國立臺灣海洋大學:材料工程研究所
Date: 2012-08
Issue Date: 2013-10-07T02:20:17Z
Publisher: 行政院國家科學委員會
Abstract: 摘要:奈米結構材料因其材料尺寸減小至奈米尺度,使其材料特性因量子尺寸效應、電子 相干效應及表面效應等之影響而呈現與一般塊材不同的特性。然而,對材料結構內的原 子來說,如不將材料尺度侷限固定,則在奈米尺度發生之系列研究,仍屬於此類自由奈 米粉體。材料如若將其侷限在奈米尺度環境下,由於奈米侷限不同於具自由表面之奈米 粒子,它是將奈米大小物質被侷限在一個不反應性的固體內,顯然地,在此情形下,材 料之表面能與應變能將有別於自由奈米材料。因而,材料的相想當然爾會受奈米侷限影 響。 本計畫為三年期之整合型研究計畫之子計畫四,研究主題是『奈米侷限下陶瓷相變 行為研究』,探討二氧化鋯陶瓷材料於奈米侷限下之相變化。純的氧化鋯具有三種多形 態,其相變化呈現:單斜相(m)⎯1⎯170⎯o C→四方相(t)⎯2⎯370⎯o C→立方相(c),其中氧化鋯麻田散 體相變(t→m)之起始溫度(Ms)存在一臨界現象,亦即其有一臨界尺寸dc,小於dc 則此相 轉換不會發生。由於氧化鋯麻田散體相變之影響因素牽涉到相轉換過程表面能與應變能 等之變化。因此在第一年的研究計畫中,利用無電鍍銅方式將選備之微、奈米氧化鋯顆 粒將之作奈米侷限,研究探討臨界尺寸效應可能的變化與機制。在第二年的研究計畫 中,對奈米侷限下的氧化鋯顆粒進行離子佈植,增添晶格應變能的變化來研究探討臨界 尺寸效應可能的變化與機制。而在第三年的研究計畫中,將與其他子計畫合作進行冷、 熱加工,研究探討奈米侷限下,應力誘發氧化鋯麻田散體相變之臨界現象,最後與其他 子計畫的結果比較討論。
Abstract: Nanostructured materials would show the distinct characteristics from common bulk materials as results of size reduction down to nanoscale, which caused quantum size effect, quantum tunneling effect, surface effect, and so on. However, the characteristic study under nanoscale for the atoms in the material structure without size confinement still would be part of free nano particles. Suppose that the material structure was constrained under nano size, that is, the nano particle was constrained in a non-reactive matrix, it would be distinct from the nano particle with free surface. Apparently, in this circumstance, the surface energy and strain energy of materials would be different from free nano materials. Hence, the microstructure phase of materials would be presumably influenced due to nano confinement. This is a sub-project of integrated project of three years. The main subjects of the proposal in the first year are focused on phase transformation study for ZrO2 ceramic nano particles under nano confinement. Generally, pure zirconia shows three varieties of crystal structure, and presents phase transformation: monoclinic (m)⎯1⎯170⎯o C→tetragonal (t)⎯2⎯370⎯o C→cubic (c). There existed a critical crystallite size, dc, above which the metastable tetragonal phase tranforms into the monoclinic phase, m. Since ZrO2 martensite transformation is influenced on the change of the surface energy and the strain energy before and after the transformation, in order to study the phenomenon of critical size effect, the prepared micro and nano zirconia particles were constrained by using the coating of an electroless copper layer in the first year proposal. Next, in the second year proposal, ion implantation was used to nano confinement ZrO2 nanoparticles. The phenomenon of critical size effect was also investigated by inducing the change of lattice strain energy. Finally, in the three year proposal, cold and hot working was used to study the phenomenon of critical size effect due to stress-induced phase transformation.
Relation: NSC99-2221-E019-010-MY3
URI: http://ntour.ntou.edu.tw/handle/987654321/34295
Appears in Collections:[材料工程研究所] 研究計畫

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