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spelling todo:paper_39013841_v_n_p490_Martinez2023-10-03T16:42:28Z Microscopic characterization of metallic surfaces by photoinduced thermoelastic bumps Martínez, O.E. Balzarotti, F. Mingolo, N. Alloys Deformation Heat treating furnaces Heat treatment Laser heating Lasers Liquid metals Metallic compounds Metallic glass Metals Modulation Quenching Surface analysis Surface diffusion Surface treatment Technology Thermal expansion Thermal spraying Thermodynamic properties Thermoelasticity Analytical modelling Beam diameters Critical frequencies Heat diffusions International Federation for Heat Treatment Knife edge Laser modulation Local heating Metal surfaces Metallic glasses Metallic surfaces Micron-scale Microscopic characterization Modulation period Non-contact Photo-induced Reflected signals Surface deformations Surface engineering Thermal properties Surface properties A non contact technique is presented, that provides information on thermal properties at the cubic micron scale in metal surfaces. It makes use of the appearance of bumps originated in the thermoelastic deformation of the surface induced by laser heating with a modulated beam. The heat diffusion and thermal expansion give rise to a surface deformation shaping a modulated bump at the laser modulation frequency. A second beam is reflected at the bump and the collected amplitude depends both on the change in reflectivity with temperature (thermoreflectance) and the deflection of the beam due to the surface deformation (photodeflection). Filtering the reflected signal with an adjusTable knife edge the photodeflection signal can be enhanced. A complete analytical model is presented that takes into account both mechanisms. A critical modulating frequency appears at which the heat diffuses the entire laser beam diameter in one modulation period. From the determination of that critical frequency the local heat diffusivity can be determined. Experimental results are presented on poor conducting metallic glasses, confirming the theoretical predictions. Fil:Martínez, O.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Mingolo, N. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. CONF info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_39013841_v_n_p490_Martinez
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Alloys
Deformation
Heat treating furnaces
Heat treatment
Laser heating
Lasers
Liquid metals
Metallic compounds
Metallic glass
Metals
Modulation
Quenching
Surface analysis
Surface diffusion
Surface treatment
Technology
Thermal expansion
Thermal spraying
Thermodynamic properties
Thermoelasticity
Analytical modelling
Beam diameters
Critical frequencies
Heat diffusions
International Federation for Heat Treatment
Knife edge
Laser modulation
Local heating
Metal surfaces
Metallic glasses
Metallic surfaces
Micron-scale
Microscopic characterization
Modulation period
Non-contact
Photo-induced
Reflected signals
Surface deformations
Surface engineering
Thermal properties
Surface properties
spellingShingle Alloys
Deformation
Heat treating furnaces
Heat treatment
Laser heating
Lasers
Liquid metals
Metallic compounds
Metallic glass
Metals
Modulation
Quenching
Surface analysis
Surface diffusion
Surface treatment
Technology
Thermal expansion
Thermal spraying
Thermodynamic properties
Thermoelasticity
Analytical modelling
Beam diameters
Critical frequencies
Heat diffusions
International Federation for Heat Treatment
Knife edge
Laser modulation
Local heating
Metal surfaces
Metallic glasses
Metallic surfaces
Micron-scale
Microscopic characterization
Modulation period
Non-contact
Photo-induced
Reflected signals
Surface deformations
Surface engineering
Thermal properties
Surface properties
Martínez, O.E.
Balzarotti, F.
Mingolo, N.
Microscopic characterization of metallic surfaces by photoinduced thermoelastic bumps
topic_facet Alloys
Deformation
Heat treating furnaces
Heat treatment
Laser heating
Lasers
Liquid metals
Metallic compounds
Metallic glass
Metals
Modulation
Quenching
Surface analysis
Surface diffusion
Surface treatment
Technology
Thermal expansion
Thermal spraying
Thermodynamic properties
Thermoelasticity
Analytical modelling
Beam diameters
Critical frequencies
Heat diffusions
International Federation for Heat Treatment
Knife edge
Laser modulation
Local heating
Metal surfaces
Metallic glasses
Metallic surfaces
Micron-scale
Microscopic characterization
Modulation period
Non-contact
Photo-induced
Reflected signals
Surface deformations
Surface engineering
Thermal properties
Surface properties
description A non contact technique is presented, that provides information on thermal properties at the cubic micron scale in metal surfaces. It makes use of the appearance of bumps originated in the thermoelastic deformation of the surface induced by laser heating with a modulated beam. The heat diffusion and thermal expansion give rise to a surface deformation shaping a modulated bump at the laser modulation frequency. A second beam is reflected at the bump and the collected amplitude depends both on the change in reflectivity with temperature (thermoreflectance) and the deflection of the beam due to the surface deformation (photodeflection). Filtering the reflected signal with an adjusTable knife edge the photodeflection signal can be enhanced. A complete analytical model is presented that takes into account both mechanisms. A critical modulating frequency appears at which the heat diffuses the entire laser beam diameter in one modulation period. From the determination of that critical frequency the local heat diffusivity can be determined. Experimental results are presented on poor conducting metallic glasses, confirming the theoretical predictions.
format CONF
author Martínez, O.E.
Balzarotti, F.
Mingolo, N.
author_facet Martínez, O.E.
Balzarotti, F.
Mingolo, N.
author_sort Martínez, O.E.
title Microscopic characterization of metallic surfaces by photoinduced thermoelastic bumps
title_short Microscopic characterization of metallic surfaces by photoinduced thermoelastic bumps
title_full Microscopic characterization of metallic surfaces by photoinduced thermoelastic bumps
title_fullStr Microscopic characterization of metallic surfaces by photoinduced thermoelastic bumps
title_full_unstemmed Microscopic characterization of metallic surfaces by photoinduced thermoelastic bumps
title_sort microscopic characterization of metallic surfaces by photoinduced thermoelastic bumps
url http://hdl.handle.net/20.500.12110/paper_39013841_v_n_p490_Martinez
work_keys_str_mv AT martinezoe microscopiccharacterizationofmetallicsurfacesbyphotoinducedthermoelasticbumps
AT balzarottif microscopiccharacterizationofmetallicsurfacesbyphotoinducedthermoelasticbumps
AT mingolon microscopiccharacterizationofmetallicsurfacesbyphotoinducedthermoelasticbumps
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