Slot-Die Coating Operability Window for Nanoparticle Bed Deposition in a Microscale Selective Laser Sintering Tool
Slot-Die Coating Operability Window for Nanoparticle Bed Deposition in a Microscale Selective Laser Sintering Tool
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DOI：
10.1115/1.4049668
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发表时间：
2020-12-01
影响因子：
1
通讯作者：
Cullinan, Michael A.
中科院分区：
文献类型：
--
作者：
Behera, Dipankar;Liao, Daniel;Cullinan, Michael A.
这项工作的目的是发展一个基本的理解狭缝模具涂层作为纳米粒子床沉积机制的微尺度选择性激光烧结（μ-SLS）过程。mu-SLS工艺对存款均匀的亚5 μ m金属纳米颗粒膜同时能够实现高产量制造的特定要求使得狭缝模头涂布工艺成为逐层沉积的强有力的候选者。涂层系统的关键挑战是以间歇的逐层方式实现均匀的纳米颗粒油墨沉积。确定实验参数，以实现这一点，使用狭缝模头涂布工艺是困难的。因此，本研究的主要贡献是开发一个框架来预测湿膜厚度和涂层缺陷的发生，通过模拟的mu-SLS过程的实验条件。通过实验和二维计算流体动力学模拟研究了狭缝模头涂布装置的单层沉积特性和操作窗口。分析了入口速度、涂布速度、涂布间隙等涂布参数对湿膜厚度的影响。对于高于涂覆速度的入口速度，发现弯月面容易受到导致涂覆缺陷的高不稳定性的影响。此外，该研究概述了槽模涂布机上游和下游的稳定性可能影响涂层均匀性和厚度范围的条件。[DOI电话：10.1115/1.4049668
This work seeks to develop a fundamental understanding of slot-die coating as a nanoparticle bed deposition mechanism for a microscale selective laser sintering (mu-SLS) process. The specific requirements of the mu-SLS process to deposit uniform sub-5 mu m metal nanoparticle films while enabling high throughput fabrication make the slot-die coating process a strong candidate for layer-by-layer deposition. The key challenges of a coating system are to enable uniform nanoparticle ink deposition in an intermittent layer-by-layer manner. Identifying the experimental parameters to achieve this using a slot-die coating process is difficult. Therefore, the main contribution of this study is to develop a framework to predict the wet film thickness and onset of coating defects by simulating the experimental conditions of the mu-SLS process. The single-layer deposition characteristics and the operational window for the slot-die coating setup have been investigated through experiments and two-dimensional computational fluid dynamics simulations. The effect of coating parameters such as inlet speed, coating speed, and coating gap on the wet film thickness has been analyzed. For inlet speeds higher than the coating speed, it was found that the meniscus was susceptible to high instabilities leading to coating defects. Additionally, the study outlines the conditions for which the stability of the menisci upstream and downstream of the slot-die coater can affect the uniformity and thickness range of the coating. [DOI: 10.1115/1.4049668]