非晶合金玻璃形成能力和纳米压痕蠕变行为的研究

发布时间：2018-04-19 04:20

本文选题：非晶合金 + 玻璃形成能力　；参考：《湘潭大学》2017年硕士论文

【摘要】：非晶合金因为其独特而优异的力学、物理和化学性能一直被人们广泛关注。非晶合金材料在国防、航空航天、体育和电力等领域都有广阔的应用前景,非晶合金的玻璃转变和纳米压痕蠕变行为都是比较热门的研究方向。虽然人们已经成功制备出了众多的非晶合金系,并且其中一部分合金已经得到了实际应用,但是非晶合金的较低玻璃形成能力(Glass forming ability, GFA),对非晶合金室温下的流变行为研究还不够全面等缺陷极大地限制了非晶合金的应用。研究非晶合金材料的玻璃形成能力GFA和它的纳米压痕蠕变行为对更好地探索非晶的性能,提高非晶的应用前景都具有重要意义。本文文主要工作和结果总结如下:1、简单介绍了非晶合金材料的研究历史、性能和应用前景和非晶合金的形成机理与压痕蠕变行为。基于文献总结了其他学者研究非晶材料的GFA的方法,如今被广泛采用的评估非晶材料的GFA的参数是临界冷却速率Rc和最大直径Dmax。其中用Rc评估非晶合金材料的GFA比较准确,但是目前测量Rc的步骤繁琐,对仪器要求较高;而用最大直径Dmax来评估非晶合金材料的GFA比较简单,但是测量最大直径Dmax时,受工艺的影响偏差比较大。因此目前主要通过含有非晶合金材料的玻璃转变温度(Tg)、晶化开始温度(Tx)、液相线温度(7l)的判据来判断临界冷却速率Rc和最大直径Dmax的大小,然后通过Rc和Dmax来反映非晶合金材料的GFA。2、通过分析不同判据△Tx、Trg、γ、△Trg、α、β1、δ、γm,、φ、ξ、β2、ω1、ω3、θ、ω2、γc、β'、ω4、Gp ,然后基于热力学和动力学的方法得到新判据χ,分析各判据与临界冷却速率Rc的相关性得出:新判据χ与Rc的相关性最强,能更好的判断Rc的大小,从而能更好的反映非晶材料的GFA。3、通过分析判据与临界冷却速率Rc和最大直径Dmax。相关性的不同,得出判据在判断临界冷却速率Rc和最大直径Dmax。的准确性上存在差异,本文通过形核速率和热稳定性分析得到了一个能更好地判断最大直径Dmax大小的新判据χ。基于统计数据分析结果发现,判据χ'与最大直径Dmax的相关性最强,能更好的判断最大直径Dmax的大小,从而反映非晶合金的玻璃形成能力GF4。4、基于分数阶Maxwell、kevin和Zener模型,推导得到各模型在保载阶段的蠕变位移和时间关系式,并通过这些关系来分析在不同加载速率下非晶材料的纳米压痕蠕变行为。我们得到在相同最大载荷下,加载速率的增加会导致分数阶阶次α和流动单元作用因子ρ均增大,非晶材料表现出更强的粘性特征。
[Abstract]:Amorphous alloy because of its unique and excellent mechanical, physical and chemical properties have been widely concerned. Amorphous alloys in aerospace, defense, sports and power fields have broad application prospects, amorphous alloy and glass transition of nanoindentation creep behavior is a popular research. Although people has successfully prepared amorphous alloys are numerous, and part of the alloy has been applied, but lower the glass forming ability of amorphous alloys (Glass, forming ability, GFA) on the rheological behavior of the amorphous alloy at room temperature are not comprehensive defects greatly limits the application of amorphous study of amorphous alloy. The glass forming ability of GFA alloy material and its nano indentation creep behavior to better explore the properties of amorphous, is of great significance to improve the application prospects of amorphous Ben Wenwen. The main work and results are summarized as follows: 1, this paper introduces the research history of amorphous alloy material, performance and application prospect and the formation mechanism of amorphous alloys and indentation creep behavior. The paper summarizes the methods of other researchers of amorphous materials based on GFA, is now widely used to evaluate the parameters of amorphous materials GFA the critical cooling rate is Rc and the maximum diameter of Dmax. which used Rc evaluation of amorphous alloy GFA is more accurate, but the current measurement Rc cumbersome steps, higher requirement of instrument; and to evaluate the maximum diameter of Dmax amorphous alloy GFA is relatively simple, but the measurement of the maximum diameter of Dmax, the effect of deviation by process relatively large. So at present mainly through the glass transition temperature of amorphous alloy containing materials (Tg), the crystallization temperature (Tx), liquidus temperature (7L) criterion to determine the critical cooling rate of Rc and the maximum diameter of Dmax The size, and then through the Rc and Dmax to reflect the amorphous alloy material of GFA.2, through the analysis of different criteria of Tx, Trg, Trg gamma, Delta, alpha, beta 1, 8, m, gamma, phi, zeta, beta 2, Omega 1, Omega 3, Omega 2 C, theta, gamma, beta 'Omega 4, Gp, and thermodynamic and kinetic methods based on the new criterion of X, analysis of correlations between the criterion and the critical cooling rate of Rc: a new criterion was the strongest correlation with Rc, to determine the size of Rc can be better, can better reflect the amorphous material GFA.3, through the analysis and critical criterion the cooling rate of Rc and the maximum diameter of Dmax. between different criteria in accuracy that the critical cooling rate of Rc and Dmax. in diameter on the differences, through the analysis of the nucleation rate and the thermal stability has been a better judge by new criterion of maximum diameter of Dmax. The size of the statistical data analysis results based on the criterion X and the maximum diameter of the Dmax The strongest, to determine the size of Dmax in diameter can be better, so as to reflect the glass forming ability of amorphous alloys GF4.4, fractional Maxwell based on Kevin and Zener model, deduced creep displacement and time relation of the model in the holding stage, and through the relationship between the nanoindentation creep behavior under different loading rate amorphous materials. We are in the same under the maximum load, the increase of the loading rate leads to fractional order alpha and flow unit factor P increased, amorphous materials exhibit stronger viscous characteristics.

【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG139.8

【参考文献】