Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403


공학

한국표면공학회지 (35권3호 149-157)

A Study on the Infrared Radiation Properties of Anodized Aluminum

양극산화된 알루미늄의 적외선 복사특성 연구

강병철;최정진;김기호;
;;;

한국건자재시험연구원;충북대학교 재료공학과;
한국건자재시험연구원;충북대학교 재료공학과;

Abstract

Spectral emissivity depends on the surface conditions of the materials. The mechanisms that affect the spectral emissivity in anodic oxide films on aluminum were investigated. The aluminum specimens were anodized in a sulfuric acid solution and the thickness of the resulting oxide film formed changed with the anodizing time. FT-IR spectrum analysis identified the anodic oxide film as boehmite ($Al_2$$O_3$.$H_2$O). Both the infrared emisivity and reflectivity of the anodized aluminum were affected by the structure of the anodic oxide film because Al-OH and Al-O-Al have a pronounced absorption band in the infrared region of the spectrum. The presence of an anodic oxide film on aluminum caused a rapid drop in the infrared reflectivity. An aluminum surface in the clean state had an emissivity of approximately 0.2. However, the infrared emissivity rapidly increased to 0.91 as the thickness of the anodic oxide film increased.

Keywords

Anodized aluminium;aluminium;boehmite;spectral emissivity;reflectivity;FTIR;