Durable surfaces with high emissivity for cryogenic applications

0540880 - ÚPT 2021 NL eng A - Abstract
Frolec, Jiří - Králík, Tomáš - Urban, Pavel - Srnka, Aleš
Durable surfaces with high emissivity for cryogenic applications.
2nd International Conference on Cryogenics and Refrigeration Technologies. Proceedings. Postbus: CSE, 2018.
[International Conference on Cryogenics and Refrigeration Technologies /2./. 07.05.2018-10.05.2018, Bucharest]
Institutional support: RVO:68081731
Keywords : heat transfer * thermal radiation * cryogenics * surface finish
OECD category: Thermodynamics

Surfaces with high emission or absorption of thermal radiation are usually prepared by application of high emitting coatings or paints. However, such surface finishes may be prone to lower mechanical resistance or other drawbacks. In this paper, we present durable metallic and ceramic materials with bare surfaces having elevated emission of thermal radiation at low temperatures. We measured total hemispherical emissivity of austenitic stainless steel and Ti 6Al 4V alloy, both sand-blasted with two different sizes of abrasive media, and bulk Al2O3 ceramic from 30 K up to room temperatures. The emissivities of Al2O3 surface range from 50% to 75% while in the case of metallic samples the values gradually increase with increasing temperature up to 45% and depend on the size of the used abrasive media. Sand-blasted samples, particularly the Ti 6Al 4V surface, reached extremely high values compared to other metals, opening up new possibilities for specific applications
Permanent Link: http://hdl.handle.net/11104/0318479