The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
L A Dobrzanski - One of the best experts on this subject based on the ideXlab platform.
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microstructure and selected properties of hot work tool steel with pvd coatings after Laser surface treatment
Applied Surface Science, 2008Co-Authors: Marcin Adamiak, L A DobrzanskiAbstract:The paper presents the effect of HPD Laser treatment on the microstructure and selected properties of the PVD CrN, (Ti,Al) and Ti(C,N) coatings deposited onto hot-work tool steel substrates. The microstructure and surface topography of the investigated samples are characteristic of the diversified morphology connected with the applied Laser Beam Power. Employment of Laser Beam at 0.7 kW Power to the Laser treatment of samples with Ti(C,N) coatings causes clear coating adhesion growth because of the diffusive processes induced by heat release. Because of the higher value of the (Ti,Al)N absorption coefficient one can state that the observed substrate materials change and finally coatings destruction in case of those samples is the most noticeable. The moderate effect of the Laser Beam treatment of the hot-work tool steel with the PVD coating was observed for CrN coatings. However, for Laser Beam Power above 0.5 kW differences in the thermal expansion coefficients of the substrate materials and coatings generate coating crackings.
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Comparison of the abrasion wear resistance of the X40CrMoV5-1 and 55NiCrMoV7 hot work tool steels with their surface layer enriched with the ceramic powders
Journal of achievements in materials and manufacturing engineering, 2006Co-Authors: L A Dobrzanski, E. Jonda, A. PolokAbstract:Purpose: In the paper there are presented the results of the influence of Laser remelting parameters on the properties of the surface layer of the X40CrMoV5-1 and 55NiCrMoV7 hot work steel, using the high Power diode Laser (HPDL). The aim of this work was to compare the abrasion wear resistance of the X40CrMoV5-1 and 55NiCrMoV7 hot work tool steel surface layers enriched with the TiC, WC and VC ceramic powders. The surface layers of hot work tool steel remelted with a diode Laser Beam have been metallographically examined and analyzed with the use of a hardness testing machine. Design/methodology/approach: The high Power diode Laser (HPDL) and ceramic powders WC, VC and TiC were used. Remelting and alloying processes were carried out at the constant remelting rate and focus shape, varying the Laser Beam Power for the alloyed test pieces in the range from 1,2 – 2,3 kW. Findings: On the basis of the wear abrasion tests carried out on 55NiCrMoV7 and X40CrMoV5-1 steels it could be ascertained that each of those steels is characterized by different resistance for the same powders and the Power of the Laser Beam. In the case of employing 1,2 kW Laser, the surface layer formed using the majority of the investigated portions undergoes a total wear during the wear-rate test which also causes the wear of the initial material. When 2,3 kW is employed, the surface layers have crack and microcrack defections which decrease the resistance to the abrasion. The smallest mass loss for 55NiCrMoV7 steel among all the analyzed cases has been observed for the surface layers alloyed with TiC powder, at the of the Laser Beam Power of 2,3 kW and for WC powder at 1,2 kW Laser Beam Power. For the X40CrMoV5-1 steel the smallest mass decrement has been observed for the steel alloyed with WC powder at 1,2 kW Laser Beam Power and VC powder at 1,6 kW Laser Beam Power. Practical implications: The investigations showed that as a result of the applied Laser processing there is the increase in the hardness and resistance to abrasion of the surface layers in relation to the output material.
M. Wautelet - One of the best experts on this subject based on the ideXlab platform.
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Structural and optical properties of Laser-synthesized copper oxide films
Journal of Materials Research, 1993Co-Authors: M. Wautelet, F. Hanus, A. Roos, Roberto Lazzaroni, G. LambinAbstract:Thin copper films are deposited onto glass and irradiated, in air, by means of a scanned Ar + Laser Beam. The kinetics of oxidation are measured by an interferometric method. The Laser-synthesized oxide films are characterized by optical microscopy, scanning tunneling microscopy, and optical spectroscopy. It is shown that the oxidation kinetics, as well as the structural and optical properties of the oxide, depend on the Laser Beam Power and on the initial thickness of the copper film. It is argued that these facts are related to the thermal history of the samples under Laser irradiation.
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Kinetics of CW Laser-induced crystallization and oxidation of thin, Sb, Se, and Sb_2Se_3 films in air
Applied Physics A, 1991Co-Authors: K. Kolev, M. WauteletAbstract:Thin films of Sb, Se and Sb_2Se_3 are deposited onto glass and irradiated by a cw-Ar^+ Laser Beam. The kinetics of crystallization and oxidation are traced via the time dependence of optical reflectivity and temperature, T , of the irradiated zone. For Sb_2Se_3, transformations start abruptly when T attains a critical value, T _c, independently of the Laser Beam Power. These T _c values are comparable to the ones observed under furnace annealing conditions.
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Kinetics of CW Laser-induced crystallization and oxidation of thin, Sb, Se, and Sb2Se3 films in air
Applied Physics A Solids and Surfaces, 1991Co-Authors: K. Kolev, M. WauteletAbstract:Thin films of Sb, Se and Sb2Se3 are deposited onto glass and irradiated by a cw-Ar+ Laser Beam. The kinetics of crystallization and oxidation are traced via the time dependence of optical reflectivity and temperature, T, of the irradiated zone. For Sb2Se3, transformations start abruptly when T attains a critical value, Tc, independently of the Laser Beam Power. These Tc values are comparable to the ones observed under furnace annealing conditions.
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Thickness‐dependent kinetics of Laser‐induced oxidation of thin copper films
Applied Physics Letters, 1991Co-Authors: M. Wautelet, F. HanusAbstract:Thin copper films are deposited onto glass and irradiated, in air, by means of a scanned Ar+ Laser Beam. The kinetics of oxidation is measured by an interferometric method. It is shown that the kinetics of oxidation depends on the Laser Beam Power density and on the initial thickness of the deposited copper films.
Grzegorz Kinal - One of the best experts on this subject based on the ideXlab platform.
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microstructure and wear resistance of stellite 6 wc mmc coatings produced by Laser cladding using yb yag disk Laser
International Journal of Refractory Metals & Hard Materials, 2016Co-Authors: Dariusz Bartkowski, Grzegorz KinalAbstract:Abstract The paper focuses on the study results of Stellite-6/WC metal matrix composite coatings (MMC coatings) produced by Laser cladding technology using a 1 kW continuous wave Yb: YAG disk Laser with powder feeding system. Specimens were preparation using CNC machining center equipped with a Laser nozzle. Powder mixtures containing 60% tungsten carbides particles and 40% commercial Stellite-6 powder were used. In this study, three different values of Laser Beam Power (400 W, 550 W and 700 W) and three different powder feed rate (5.12 g/min, 10.24 g/min and 15.36 g/min) were used. For all specimens, the same scanning speed of Laser Beam were applied. Changes in roughness, microstructure as well as wear resistance were investigated. It was found that increasing Laser Beam Power caused a decrease in wear resistance of coating. Furthermore in described process appeared the best value of the powder feed rate which potentially resulting in better wear resistance. Exceeding this value influence on more intensive wear of coating. Special attention was given to the wear mechanism of MMC coatings.
Dariusz Bartkowski - One of the best experts on this subject based on the ideXlab platform.
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microstructure and wear resistance of stellite 6 wc mmc coatings produced by Laser cladding using yb yag disk Laser
International Journal of Refractory Metals & Hard Materials, 2016Co-Authors: Dariusz Bartkowski, Grzegorz KinalAbstract:Abstract The paper focuses on the study results of Stellite-6/WC metal matrix composite coatings (MMC coatings) produced by Laser cladding technology using a 1 kW continuous wave Yb: YAG disk Laser with powder feeding system. Specimens were preparation using CNC machining center equipped with a Laser nozzle. Powder mixtures containing 60% tungsten carbides particles and 40% commercial Stellite-6 powder were used. In this study, three different values of Laser Beam Power (400 W, 550 W and 700 W) and three different powder feed rate (5.12 g/min, 10.24 g/min and 15.36 g/min) were used. For all specimens, the same scanning speed of Laser Beam were applied. Changes in roughness, microstructure as well as wear resistance were investigated. It was found that increasing Laser Beam Power caused a decrease in wear resistance of coating. Furthermore in described process appeared the best value of the powder feed rate which potentially resulting in better wear resistance. Exceeding this value influence on more intensive wear of coating. Special attention was given to the wear mechanism of MMC coatings.
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microstructure microhardness and corrosion resistance of stellite 6 coatings reinforced with wc particles using Laser cladding
Optics and Laser Technology, 2015Co-Authors: Dariusz Bartkowski, A Mlynarczak, Adam Piasecki, Bartlomiej Dudziak, Marek Gościanski, Aneta BartkowskaAbstract:Abstract The paper presents the method of preparation and study results of metal matrix composite coatings (MMC coating) in the system of Stellite-6 and tungsten carbides. Changes in microstructure, corrosion resistance, microhardness, phase and chemical composition as well as surface conditions were investigated. Stellite-6/WC MMC coatings were prepared by Laser cladding technology using a 1 kW continuous wave Yb:YAG disk Laser with a powder feeding system. Two different powder mixtures containing 30% and 60% of WC and three different values of Laser Beam Power were used. It was found that increasing WC values caused an increase in microhardness on the cross-section of the produced coating in comparison to the substrate. Depending on the Laser Beam Power, the coatings produced with 30% WC achieved microhardness in the range from about 350 HV0.05 (700 W) to about 680 HV0.05 (550 W). Twice as large amount of WC particles in the powder mixture resulted in increase of microhardness from about 700 HV0.05 (700 W) to about 1500 HV0.05 (550 W). In the coating M7C3, M6C and M23C6 carbides were identified by an X-ray diffraction method. Special attention was given to bondings between carbide particles and metal matrix, which had a characteristic microstructure. A reduction of corrosion resistance with increasing WC content in coating was also discovered.
Marcin Adamiak - One of the best experts on this subject based on the ideXlab platform.
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microstructure and selected properties of hot work tool steel with pvd coatings after Laser surface treatment
Applied Surface Science, 2008Co-Authors: Marcin Adamiak, L A DobrzanskiAbstract:The paper presents the effect of HPD Laser treatment on the microstructure and selected properties of the PVD CrN, (Ti,Al) and Ti(C,N) coatings deposited onto hot-work tool steel substrates. The microstructure and surface topography of the investigated samples are characteristic of the diversified morphology connected with the applied Laser Beam Power. Employment of Laser Beam at 0.7 kW Power to the Laser treatment of samples with Ti(C,N) coatings causes clear coating adhesion growth because of the diffusive processes induced by heat release. Because of the higher value of the (Ti,Al)N absorption coefficient one can state that the observed substrate materials change and finally coatings destruction in case of those samples is the most noticeable. The moderate effect of the Laser Beam treatment of the hot-work tool steel with the PVD coating was observed for CrN coatings. However, for Laser Beam Power above 0.5 kW differences in the thermal expansion coefficients of the substrate materials and coatings generate coating crackings.
