Development of micro-heating elements based on bilayers PVD coatings and evaluation of their robustness under electro thermal and cavitation erosive load in nucleate boiling

基于双层 PVD ​​涂层的微加热元件的开发及其在核态沸腾电热和空化侵蚀载荷下的鲁棒性评估

• 批准号: 276800743
• 负责人: Dr. Herbert Scheerer
• 金额: --
• 依托单位: Fachgebiet und Institut für Werkstoffkunde
• 依托单位国家: 德国
• 项目类别: Research Grants (Transfer Project)
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/276800743?language=en
• 关键词: Development; micro; heating; elements; based

In the DFG-project "Development of a microstructural approach to suppress the effect of growth defects in PVD coatings" developed chromium-based coatings meet the basic requirements for the design of a heating element. The heaters are constructed out of a PVD bilayer that is used for heating, temperature measurement and as well for the investigation of bubble formation processes, which are necessary to study heat transfer processes in nucleate boiling [FISH 2011 FISH 2012 Slom 2013a].Using selectively functionalized PVD coatings, micro-heater will be developed, enabling the analysis and evaluation of nucleate boiling processes at the International Space Station. Therefore the coating has to withstand terms of electro-thermal, cavitation pitting and erosive loads. The substrates used for the applied coating were made out of transparent materials such as barium fluoride or barium sulfide. These heaters have to be highly adapted in their geometric design to the boiling experiments on the ISS, for example minimum usage of space. The chromium nitride base layer has to be manufactured in the way that it enables, due to its high emissivity, the temperature measurement in the boiling zone by means of infrared thermography. The base layer which is deposited directly on the barium fluoride requires high electrical resistance. In particular higher than the Chromium top layer. For this reason, only the Chromium top-layer acts as a heater. In order to guarantee the required heating temperature of the fluid, the coatings have to possess defined electrical resistance in the required temperature ranges.

在DFG项目中，“开发一种微结构方法来抑制PVD涂层中生长缺陷的影响”开发的基于铬的涂料满足了加热元件设计的基本要求。加热器是用PVD双层构造的，用于加热，温度测量以及对气泡形成过程的研究，这对于研究成核沸腾的传热过程是必要的[Fish 2011 Fish 2012 Slom 2013a]。选择性官能化的PVD涂料，Microheatized PVD涂料将在分析和评估库中进行分析。因此，涂层必须承受电热，气蚀点和侵蚀载荷的术语。用于涂层涂层的底物是由透明材料（例如氟化钡或硫化钡）制成的。这些加热器必须在其几何设计中高度适应于ISS上的沸腾实验，例如最少的空间使用情况。氮化铬基层必须按照其高发射率，通过红外热量表在沸腾区中的温度测量来制造。直接沉积在氟化钡上的基层需要高电阻。特别是高于铬顶层。因此，只有铬顶层充当加热器。为了保证流体所需的加热温度，涂料必须在所需温度范围内具有明确的电阻。

项目成果

Experimental Investigation of Single Bubble Nucleate Boiling in Microgravity

• DOI: 10.1007/s12217-020-09813-z
• 发表时间: 2020-07
• 期刊: Microgravity Science and Technology
• 影响因子: 1.8
• 作者: I. Nejati;A. Sielaff;Benjamin Franz;M. Zimmermann;Philipp Hänichen;K. Schweikert;Julian Krempel;P. Stephan;Anne Martin;H. Scheerer;T. Engler;M. Oechsner