本文選題：非晶晶化 + 多晶型轉變��； 參考：《西北工業(yè)大學》2015年博士論文

【摘要】：高性能金屬材料制備過程中，基于固態(tài)相變原理的熱處理技術是不可或缺的關鍵手段。隨著金屬材料制備技術的革新，其固態(tài)相變動力學行為已無法用傳統(tǒng)理論來描述。固態(tài)相變動力學過程直接影響材料的微觀組織和結構，進而決定其性質和服役性能。因此，開展固態(tài)相變動力學研究不僅具有重要的科學意義，而且蘊含著潛在的工程應用前景。本文研究了兩種常見的金屬固態(tài)相變過程：非晶晶化和多晶型轉變。理論上，通過分析不同條件下影響固態(tài)相變動力學的因素，松弛傳統(tǒng)理論假設，提出一般性動力學理論模型。實驗上，借助熱分析技術(DSC和DIL)獲得固態(tài)相變轉變動力學曲線，結合相分析和組織分析判斷轉變機制，最終實現對理論模型的驗證。主要結論如下： 1基于解析模型，提出了動力學分析新方法。從總的有效激活能表達式出發(fā)，提出獲取形核和生長激活能的線性回歸分析方法；從轉變分數歸一化處理出發(fā)，得到判斷等溫模型迭代方法。據此獲得了多種非晶合金晶化過程的動力學參數。 2將一般形式溫度積分和初始溫度引入到解析模型中，拓展了模型應用范圍。根據激活能數值，選擇最優(yōu)溫度積分組合以保證模型精度；當轉變初始溫度不可忽略時，模型仍精確預測出動力學參數和轉變分數。該模型可成功描述Ti50Cu42Ni8非晶合金晶化動力學過程。 3拓展了解析模型中和積轉化概念，提出了同步及非同步多機制相變動力學模型。該模型可為諸多動力學現象提供合理解釋：消耗新相的子過程會導致有效生長指數逐漸降低；Avrami形核機制是由多個子過程疊加所致；無限多個非同步位置飽和子過程的綜合作用與連續(xù)形核機制等效；異常的轉變速率及Avrami指數均源自于孕育期；等。根據非同步多機制相變模型，成功分析了Mg-Cu-Y和Zr-Cu-Al非晶合金晶化動力學行為。 4針對界面控制生長固態(tài)相變，提出了普適的擴展解析模型。在獨立描述形核和生長動力學時引入熱力學因素，模型可用于描述近平衡和極端非平衡狀態(tài)下的相變過程。采用特殊的溫度積分處理，模型可同時適用于連續(xù)加熱和連續(xù)冷卻過程。利用熱膨脹儀定量表征了二元Fe基置換固溶體的奧氏體/鐵素體非等溫相變動力學行為，擴展解析模型可精確描述其全轉變動力學過程。 5從經典速率方程出發(fā)，，引入不同的熱力學驅動力，得到用于描述等溫和等時相變動力學過程的熱-動力學模型。該模型可預測完全等溫相變溫度區(qū)間，解釋等溫相變后期遲緩階段及非等溫相變中異常轉變等動力學行為�；谠撃Ｐ统晒Ψ治隽薋e-3Mn和Fe-2Co合金奧氏體/鐵素體相變動力學行為。 6基于脆性熔體Vogel-Fulcher-Tammann關系，將隨溫度變化的激活能耦合到固態(tài)相變動力學中，得到了描述非晶在過冷液相區(qū)晶化的一般性模型。根據該模型，提出了直接由晶化動力學實驗數據獲取熔體性質信息的分析方法。該模型成功描述了Zr-Cu-Al-Ni合金系的等溫和非等溫晶化動力學。
[Abstract]:During the preparation of high performance metal materials, the heat treatment technology based on the principle of solid phase transformation is an indispensable key means. With the innovation of the metal material preparation technology, the dynamic behavior of the solid phase transformation can not be described by the traditional theory. The solid state phase transformation kinetics process directly affects the microstructure and structure of the material, and then decides on it. Properties and service properties. Therefore, it is not only of important scientific significance to carry out the study of solid phase transition kinetics, but also contains potential engineering applications. In this paper, two kinds of common solid state phase transition processes: amorphous and polycrystalline transformation. In theory, the analysis of the factors affecting the kinetics of solid phase transition under different conditions is theoretically analyzed. In the experiment, the kinetic curve of the transformation of solid phase transition is obtained by thermal analysis (DSC and DIL), and the transformation mechanism is judged by phase analysis and tissue analysis, and the final verification of the theoretical model is realized. The main conclusions are as follows:
1 based on the analytical model, a new method of dynamic analysis is proposed. From the general effective activation energy expression, the linear regression analysis method for obtaining the nucleation and growth activation energy is proposed. From the transformation of the fractional normalization treatment, the iterative method of determining the isothermal model is obtained. Accordingly, the kinetic parameters of the crystallization process of various amorphous alloys are obtained.
2 the general form of temperature integral and initial temperature are introduced into the analytical model, and the application range of the model is extended. According to the activation energy value, the optimal temperature integral combination is selected to ensure the model accuracy. When the initial temperature can not be ignored, the model can predict the dynamic parameters and the transition fraction accurately. The model can describe the Ti50Cu42Ni8 successfully. Crystallization kinetics of amorphous alloys.
3 extended the concept of analytic model neutralization and transformation, and proposed a dynamic model of synchronous and asynchronous multi mechanism phase transformation. This model can provide a reasonable explanation for many dynamic phenomena: the subprocess of consumption of new phase leads to the gradual decrease of the effective growth index; the Avrami nucleation mechanism is caused by the superposition of a number of sub processes; The synthetic effect of the step position saturation process is equivalent to the continuous nucleation mechanism, and the abnormal transition rate and Avrami index are all derived from the inoculation period, and so on. The crystallization kinetics of Mg-Cu-Y and Zr-Cu-Al amorphous alloys have been successfully analyzed according to the model of the asynchronous multi mechanism phase transition.
4 a universal analytical model is proposed for the growth of solid phase transition in the interface control. The thermodynamic factors are introduced to describe the nucleation and growth kinetics independently. The model can be used to describe the phase transition process under the state of near equilibrium and extreme non equilibrium. The special temperature integral treatment can be used for continuous heating and continuous cooling. A thermal expansion instrument was used to quantitatively characterize the non isothermal phase transition kinetics of the austenite / ferrite of two element Fe base displaced solid solution. The extended analytical model can accurately describe the full transformation kinetics.
5 from the classical rate equation, the thermal dynamic model used to describe the isothermal and isothermal phase transition kinetics is obtained by introducing different thermodynamic driving forces. The model can predict the complete isothermal phase transition temperature range, explain the dynamic behavior of the delay phase in the later phase of isothermal phase transition and the abnormal transition in the non isothermal phase transition. Based on the model, the model is successful The kinetics of austenite / ferrite transformation in Fe-3Mn and Fe-2Co alloys was analyzed.
6 based on the Vogel-Fulcher-Tammann relationship of brittle melt, a general model for describing the crystallization of the amorphous phase in the supercooled liquid phase is obtained by coupling the activation energy with the change of temperature to the solid-state phase transition kinetics. Based on this model, an analytical method for obtaining the information of the melt properties directly from the experimental data of crystallization kinetics is proposed. The model is successfully described. The isothermal and non isothermal crystallization kinetics of Zr-Cu-Al-Ni alloy system was studied.
【學位授予單位】：西北工業(yè)大學
【學位級別】：博士
【學位授予年份】：2015
【分類號】：TG111.5

【參考文獻】

相關期刊論文 前10條

1 劉宗昌;;馬氏體切變學說的評價[J];內蒙古科技大學學報;2008年04期

2 常輝;周廉;張廷杰;;鈦合金固態(tài)相變的研究進展[J];稀有金屬材料與工程;2007年09期

3 盧柯,王景唐;關子非晶態(tài)合金的晶化溫度與激活能[J];材料科學進展;1987年03期

4 寧保群;劉永長;徐榮雷;楊留栓;;形變熱處理對T91鋼組織和性能的影響[J];材料研究學報;2008年02期

5 張良哲;趙憲明;吳迪;許云波;;微合金鋼等溫沉淀析出動力學模型[J];鋼鐵研究學報;2006年04期

6 康沫狂;貝氏體相變理論研究工作的主要回顧[J];金屬熱處理學報;2000年02期

7 徐祖耀;金學軍;;簡論貝氏體相變的形核與長大——復康沫狂教授等[J];材料熱處理學報;2005年06期

8 盧柯;王景唐;;非晶態(tài)合金晶化過程的一個新微觀機制[J];金屬學報;1991年01期

9 方鴻生,楊志剛,楊金波,白秉哲;鋼中貝氏體相變機制的研究[J];金屬學報;2005年05期

10 吳靜;張文征;;從相變出發(fā)理解和計算變體間位向差[J];金屬學報;2009年08期

本文編號：1947259