Research Initiation: Controlled Synthesis of Multi-ComponentUltrafine Ceramic Powders

陶瓷材料的发展在很大程度上取决于粉体的初始特性。具体要求是：粒度小（纳米范围），粒度分布窄，纯度高。出于实际/经济原因，连续而不是批量生产过程更可取。为了满足所需的粉末特性，在颗粒形成过程中需要对基本物理和化学过程进行最大程度的控制。这项工作解决了所有这些要求，并提供了一个连续和可控的精细多组分陶瓷粉末的生成系统。颗粒的生成是在气态和液态反应物的气相中完成的。反应器为多流倒转H2/O2/倒转扩散火焰。电场通过控制混凝和停留时间来控制粒径。粉末特性将用光学（非侵入式）技术进行原位测量。工作内容包括：原理论证；映射控制参数的域；与理论模型的比较及修正；并对基于原位粉末测量的闭环过程控制策略进行了验证。

Advances in ceramic materials hinge in a critical fashion on the initial powder characteristics. Specifically, the requirements are: small particle size (nanometer range), narrow size distribution and high purity. For practical/economical reasons a continuous, as opposed to batch, generation process, is preferable. To fulfill the required powder characteristics maximum control over the fundamental physical and chemical processes during particle formation is needed. The work addresses all these requirements, and offers a system for continuous and controlled generation of fine multi-component ceramic powders. The generation of the particles is done in the vapor phase from gaseous and liquid reactants. The reactor is a multi-stream inverted H2/O2/invert diffusion flame. Electric fields are used to control particle size via control of coagulation and residence time. The powder characteristics will be measured in-situ with optical (non-intrusive) techniques. The work will include: demonstration of principle; mapping the domain of the controlling parameters; comparing results with theoretical models and their modification; and examination of closed loop process control strategies based on the in-situ powder measurements.