GOALI: Fundamental Investigations of Nucleation Processes in Silicate Liquids and Glasses with a Goal of Developing Predictive Models for Glass Formation and Crystallization

GOALI：硅酸盐液体和玻璃中成核过程的基础研究，目标是开发玻璃形成和结晶的预测模型

基本信息

批准号：
1720296
负责人：
Kenneth Kelton
金额：
$ 52.41万
依托单位：
Washington University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-07-15 至 2023-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1720296&HistoricalAwards=false
关键词：
GOALI Fundamental Investigations Nucleation Processes

项目摘要

NON-TECHNICAL DESCRIPTION: Glasses have been centrally important technological materials for thousands of years. Glass ceramics (partially crystallized glasses) are also important, filling low technology applications such as stove-tops and cookware, to high technology applications such as optical waveguides, telescope mirrors, bone prosthesis and dental restorations. Used in composite armor, ceramics are able to break up impacting projectiles while a metallic backing plate absorbs the kinetic energy of the projectile. Controlling nucleation, the first step in the crystallization of a liquid or glass, is critically important for the production of glass ceramics. However, nucleation is generally understood within the context of a model that was developed for liquid formation in a gas in the early years of the last century and extended to the crystallization of liquids about 60 years ago. This model is inadequate for the level of control needed today. The previous assumptions are now questionable and so predictions often fail to agree quantitatively with experimental data. This research is aimed at developing a deeper understanding of crystal nucleation and the formulation of a more quantitative model. This new model provides a foundation for the development of computer simulations that can be used to accelerate the discovery and design of new glasses and ceramics. The project provides opportunities for graduate students to interact with industrial scientists in Corning Research and Development and leads to a career path for graduates in either industry or academia.TECHNICAL DETAILS: Glasses and glass ceramics are ubiquitous modern materials, fundamental to a wide range of applications. Understanding nucleation and growth is critical in the production of high quality glasses and ceramics and the discovery of new ones. These processes must be precisely controlled to produce the desired devitrified microstructures, including the number, type, and size of crystallites formed in the glass. Currently, gaining this control is largely empirical, resulting in long development times for new products. Glass and glass ceramics companies are therefore working to develop improved measurement and modeling capabilities, and to increase the fundamental understanding of nucleation and growth processes at or beyond the state-of-the-art in the field. This research, carried out with scientists in Corning Research and Development, focuses on the development of a deeper understanding of crystal nucleation through a coordinated experimental/modeling approach for two model silicate glasses (Ba2O-2SiO2 and Na2O-2CaO-3SiO2) Key elements include scanning calorimetric surveys to determine the temperature range of significant nucleation, measurements of the time-dependent nucleation rates as a function of temperature, X-ray and elastic neutron scattering studies of the glass and nucleating crystal phases to assess the importance of glass structure on the nucleation barrier, extending the classical theory of nucleation to include the effects of the diffuse interface between the nucleus and the liquid/glass and to take into account ordering in the liquid/glass, and incorporating computer models and simulations to test these theories. The new insights gained lay the foundation for computer models that can guide the rapid development of new glasses and glass ceramics with an optimized microstructure. These activities mirror a broad approach for accelerated materials development that is a national priority. The US is in crisis, with a decreasing number of students seeking careers in science, technology, engineering and math (STEM). This research forms an integral part of graduate student training, both in an academic and industrial environment. This project exposes students to cutting edge glass production and characterization techniques and leads to an optimal career path for graduates.

非技术描述：数千年来，眼镜一直是中央重要的技术材料。玻璃陶瓷（部分结晶的眼镜）也很重要，填充了低技术应用，例如炉灶和炊具，以用于光学波导，望远镜镜，骨头假体和牙科修复等高科技应用。用于复合装甲的陶瓷能够分解撞击的弹丸，而金属衬板吸收了弹丸的动能。控制成核是液体或玻璃结晶的第一步，对于生产玻璃陶瓷至关重要。然而，在上个世纪初期为气体形成的模型开发的模型中，通常可以理解成核，并扩展到大约60年前的液体结晶。对于当今所需的控制水平，该模型不足。以前的假设现在是值得怀疑的，因此预测通常无法与实验数据进行定量一致。这项研究旨在对晶体成核和更定量模型的制定有更深入的了解。这种新模型为开发计算机模拟的基础提供了基础，可用于加速新眼镜和陶瓷的发现和设计。该项目为研究生提供了与工业科学家在康宁研究和开发中互动的机会，并导致行业或学术界毕业生的职业道路。技术细节：眼镜和玻璃陶瓷是无处不在的现代材料，是广泛应用的基础。了解成核和生长对于高质量眼镜和陶瓷的生产以及新发现至关重要。这些过程必须得到精确控制，以产生所需的Devitrified微结构，包括玻璃中形成的微晶的数量，类型和大小。目前，获得此控制的基本面是经验性的，这导致了新产品的漫长开发时间。因此，玻璃和玻璃陶瓷公司正在努力开发改进的测量和建模能力，并提高对现场最新面临或以后的成核和生长过程的基本理解。这项研究与科学家在康宁的研究和发展中进行，重点是通过对两个模型硅酸盐玻璃（BA2O-2SIO2和Na2O-2CAO-3SIO2）的协调实验/建模方法对晶体成核的更深入了解，包括对扫描量表的量化范围的量化范围，以确定量化量范围，以确定量化的量化量，该量范围的量化量范围，该量范围是构造的，构造了构造的量化量的量化范围，该量的量化量范围逐步划分，构成了构造的量化量范围，这些构成范围逐步划分，逐步划分量范围，逐步量化了量化量的量化范围。玻璃的温度，X射线和弹性中子散射研究和成核晶体相，以评估玻璃结构对成核屏障的重要性，从而扩展了成核的经典理论，以包括核和液体/玻璃之间的弥漫性界面的影响，并在液体/玻璃之间以及在计算机/玻璃中考虑这些计算机模型和仿真的液体订购。获得的新见解为计算机模型奠定了基础，这些计算机模型可以通过优化的微观结构来指导新眼镜和玻璃陶瓷的快速开发。这些活动反映了一种广泛的方法，用于加速材料开发，这是国家优先事项。美国处于危机状态，在科学，技术，工程和数学（STEM）领域寻求职业的学生人数减少。这项研究构成了在学术和工业环境中研究生培训的组成部分。该项目使学生接触了尖端的玻璃生产和表征技术，并为毕业生带来了最佳的职业道路。