Spectral BRDF measurements of metallic samples for laser processing applications

33rd UIT (Italian Union of Thermo-fluid dynamics) Heat Transfer Conference

物理学;力学

Vitali, L.^1 ; Fustinoni, D.^1 ; Gramazio, P.^1 ; Niro, A.^1

Politecnico di Milano, Department of Energy, Campus Bovisa, Via Lambruschini 4, Milano

20156, Italy^1

关键词: Absolute reflectance;    Affect processing;    Bidirectional reflectance distribution functions;    Industrial processing;    Perkin-Elmer Lambda;    Polishing processs;    Radiation incidence;    Resulting optical properties;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/655/1/012064/pdf
DOI  :  10.1088/1742-6596/655/1/012064

学科分类：力学，机械学

来源: IOP

【 摘 要 】

The spectral bidirectional reflectance distribution function (BRDF) of metals plays an important role in industrial processing involving laser-surface interaction. In particular, in laser metal machining, absorbance is strongly dependent on the radiation incidence angle as well as on finishing and contamination grade of the surface, and in turn it can considerably affect processing results. Very recently, laser radiation is also used to structure metallic surfaces, in order to produce many particular optical effects, ranging from a high level polishing to angular color shifting. Of course, full knowledge of the spectral BRDF of these structured layers makes it possible to infer reflectance or color for any irradiation and viewing angles. In this paper, we present Vis-NIR spectral BRDF measurements of laser-polished metallic, opaque, flat samples commonly employed in such applications. The resulting optical properties seem to be dependent on the atmospheric composition during the polishing process in addition to the roughness. The measurements are carried out with a Perkin Elmer Lambda 950 double-beam spectrophotometer, equipped with the Absolute Reflectance/Transmittance Analyzer (ARTA) motorized goniometer.