Surface condition, microstructure and microhardness of boronized layers produced on Vanadis-6 steel after modification by diode laser

AbstractThe paper presents the study results of surface condition, microstructure and microhardness of Vanadis-6 tool steel after diffusion boriding and laser modification by diode laser. As a result of diffusion boriding the layers consisted of two phases: FeB and Fe2B. A bright area under the continuous boronized layers was visible. This zone was probably rich in boron. As a result of laser surface modification of boronized layers, the microstructure composed of three zones: remelted zone, heat affected zone and the substrate was obtained. The microstructure of remelted zone consisted of boron-martensite eutectic. The depth of laser track (total thickness of remelted zone and heat affected zone) was dependent on laser parameters (laser beam power density and scanning laser beam velocity). The microhardness of laser remelting boronized layer in comparison with diffusion boronized layer was slightly lower. The presence of heat affected zone was advantageous, because it allowed to obtain a mild microhardness gradient between the layer and the substrate.

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Microstructural and Mechanical Properties of B-Cr Coatings Formed on 145Cr6 Tool Steel by Laser Remelting of Diffusion Borochromized Layer Using Diode Laser

Coatings ◽

10.3390/coatings11050608 ◽

2021 ◽

Vol 11 (5) ◽

pp. 608

Author(s):

Aneta Bartkowska ◽

Dariusz Bartkowski ◽

Damian Przestacki ◽

Jakub Hajkowski ◽

Andrzej Miklaszewski

Keyword(s):

Wear Resistance ◽

Corrosion Resistance ◽

Laser Beam ◽

Diode Laser ◽

Tool Steel ◽

The Other ◽

Beam Power ◽

Other Hand ◽

Laser Beam Power ◽

Study Results

The paper presents study results focused on the microstructural, mechanical, and physicochemical properties of B-Cr coatings obtained by means of modification of diffusion borochromized layers by diode laser beam. The studies were conducted on 145Cr6 tool steel. Diffusion borochromized layers were produced at 950 °C in powder mixture containing boron carbides as a source of boron and ferrochrome as a source of chromium. In the next step these layers were remelted using laser beam. Powers: 600, 900, and 1200 W were used during these processes. The microstructure, microhardness, chemical composition, as well as wear and corrosion resistance of newly-formed B-Cr coatings were determined. As a result of laser beam interaction, the diffusion borochromized layer was mixed with the steel substrate. The study showed that too low laser beam power causes cracks in the newly formed B-Cr coating, and on the other hand, too higher laser beam power causes deep remelting resulting in the loss of microhardness. The reduced corrosion resistance in comparison with diffusion borochromized layers was caused by occurrence cracks or deep remelting. For B-Cr coatings produced using laser beam power 600 W, a small decrease in wear resistance was observed, but note that this coating was much thicker than diffusion borochromized layers. On the other hand, laser beam power of 1200 W caused a significant decrease in wear resistance. Newly formed B-Cr coatings had an advantageous microhardness gradient between the layer and the substrate.

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Fluid flows driven by light scattering

Journal of Fluid Mechanics ◽

10.1017/s0022112010004180 ◽

2010 ◽

Vol 666 ◽

pp. 273-307 ◽

Cited By ~ 26

Author(s):

R. WUNENBURGER ◽

B. ISSENMANN ◽

E. BRASSELET ◽

C. LOUSSERT ◽

V. HOURTANE ◽

...

Keyword(s):

Light Scattering ◽

Laser Beam ◽

Fluid Flows ◽

Beam Power ◽

Two Phase ◽

Core Diameter ◽

Laser Beam Power ◽

Induced Flow ◽

Two Phases ◽

Scatter Light

We report on the direct experimental observation of laser-induced flows in isotropic liquids that scatter light. We use a droplet microemulsion in the two-phase regime, which behaves like a binary mixture. Close to its critical consolute line, the microemulsion undergoes large refractive index fluctuations that scatter light. The radiation pressure of a laser beam is focused onto the soft interface between the two phases of the microemulsion and induces a cylindrical liquid jet that continuously emits droplets. We demonstrate that this dripping phenomenon takes place as a consequence of a steady flow induced by the transfer of linear momentum from the optical field to the liquid due to light scattering. We first show that the cylindrical jet guides light as a step-index liquid optical fiber whose core diameter is self-adapted to the light itself. Then, by modelling the light-induced flow as a low-Reynolds-number, parallel flow, we predict the dependence of the dripping flow rate on the thermophysical properties of the microemulsion and the laser beam power. Satisfying agreement is found between the model and experiments.

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Production and Properties of FeB-Fe2B-Fe3(B,C) Surface Layers Formed on Tool Steel Using Combination of Diffusion and Laser Processing

Coatings ◽

10.3390/coatings10111130 ◽

2020 ◽

Vol 10 (11) ◽

pp. 1130 ◽

Cited By ~ 1

Author(s):

Aneta Bartkowska

Keyword(s):

Wear Resistance ◽

Corrosion Resistance ◽

Laser Beam ◽

Tool Steel ◽

Laser Processing ◽

Steel Substrate ◽

Beam Power ◽

Slight Reduction ◽

Laser Beam Power ◽

Study Results

The paper presents the study results of laser remelting diffusion boronized layers produced on CT90 tool steel. A diffusion boronized layer was produced at 950 °C in a powder mixture containing boron carbide as a source of boron. A needle-like microstructure of iron boride was obtained. After diffusion boronizing, the specimens were subjected to laser processing, which was carried out using a diode laser with a nominal power of 3 kW. Three laser beam power values were applied (600, 900, and 1200 W). The aim of the study was to investigate the microstructure, microhardness, chemical, and phase composition as well as the wear and corrosion resistance of newly formed FeB-Fe2B-Fe3(B,C) layers. As a result of the laser beam interaction, the needle-like borides occurring in the subsurface zone were remelted, and three characteristic areas were obtained: the remelted zone, the heat-affected zone, and the substrate. The properties of newly formed layers have improved in comparison to diffusion boronized layers (except for corrosion resistance). It should be noted that using the highest laser beam power contributed to a slight reduction in wear resistance. Both the reduced corrosion and wear resistance were caused by greater remelting of the steel substrate and thus by the increased iron content in the formed layer.

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Microstructure and selected properties of boronized layers produced on C45 and CT90 steels after modification by diode laser

Archives of Mechanical Technology and Materials ◽

10.1515/amtm-2016-0010 ◽

2016 ◽

Vol 36 (1) ◽

pp. 51-58 ◽

Cited By ~ 1

Author(s):

Aneta Bartkowska ◽

Dariusz Bartkowski ◽

Damian Przestacki ◽

Małgorzata Talarczyk

Keyword(s):

Corrosion Resistance ◽

Carbon Steel ◽

Diode Laser ◽

High Carbon Steel ◽

Medium Carbon Steel ◽

High Carbon ◽

Medium Carbon ◽

Laser Surface Modification ◽

Study Results ◽

Diffusion Boriding

Abstract The paper presents the study results of macro- and microstructure, microhardness and corrosion resistance of C45 medium carbon steel and CT90 high carbon steel after diffusion boriding and laser modification by diode laser. It was found that the increase of carbon content reduced the thickness of boronized layer and caused change in their morphology. Diffusion boronized layers were composed of FeB and Fe2B iron borides. As a result of laser surface modification of these layers, the microstructure composed of three areas: remelted zone, heat affected zone (HAZ) and the substrate was obtained. Microhardness of laser remelting boronized layer in comparison with diffusion boronized layer was lower. The presence of HAZ was advantageous, because mild microhardness gradient between the layer and the substrate was assured. The specimens with laser boronized layers were characterized by better corrosion resistance than specimens without modified layer.

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The Effects of Laser Surface Modification on the Microstructure of 1.4550 Stainless Steel

MATEC Web of Conferences ◽

10.1051/matecconf/201823702009 ◽

2018 ◽

Vol 237 ◽

pp. 02009 ◽

Cited By ~ 1

Author(s):

Damian Przestacki ◽

Aneta Bartkowska ◽

Mateusz Kukliński ◽

Piotr Kieruj

Keyword(s):

Laser Beam ◽

Cooling System ◽

Steel Substrate ◽

Beam Power ◽

Beam Diameter ◽

Laser Surface Modification ◽

Heat Treated ◽

Laser Beam Power ◽

Melted Layer ◽

Stainless Austenitic Steel

In this study a stainless austenitic steel 1.4550 was laser heat treated with diode laser. The influence a gouache coating on remelted steel substrate was carry out. The cooling system during laser melted was analysis as well. Melted layers were manufactured with different laser beam power between 0.6 kW and 1.4 kW, constant scanning laser beam speed vl = 5.76 m/min and laser beam diameter equal dl = 1.2 mm. The surface was treated at room temperature and under CO2 cooling conditions and the results were compered. With the increase of the laser beam power, the dimensions of the laser tracks increase. The depth of laser tracks varies significantly than their width. The deepest melted layer was observed for a material that wasn’t coated by any of absorbent paste and when there wasn’t cooling system.

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