scholarly journals Laser Processing of Diffusion Boronized Layer Produced on Monel® Alloy 400—Microstructure, Microhardness, Corrosion and Wear Resistance Tests

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7529
Author(s):  
Aneta Bartkowska ◽  
Dariusz Bartkowski ◽  
Damian Przestacki ◽  
Mateusz Kukliński ◽  
Andrzej Miklaszewski ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Laser Beam ◽  
Scanning Speed ◽  
Substrate Material ◽  
Contact Method ◽  
Surface Layers ◽  
Laser Modification ◽  
Borided Layer ◽  
Diode Laser Beam ◽  
Boron Source

The paper presents the results of studies of microstructure, mechanical and physicochemical properties of surface layers produced by laser modification of the diffusion boron layer on Monel® Alloy 400. The diffusion boron layers were produced at 950 °C for 6 h. The gas-contact method was used in an open retort furnace. The process was carried out in a powder mixture containing B4C carbide as a boron source. The next stage was the modification of the boron layer with a diode laser beam of a nominal power of 3 kW. A constant power of 1400 W of the laser beam was used. The scanning speed was variable (successively 5 m/min, 25 m/min, 50 m/min). In order to determine the best parameters, single tracks were created, after which multiple tracks were prepared using previously selected parameters. It was found that both the diffusion borided layer and the laser modified layer had better properties than the substrate material. Both these processes contributed to an increase in corrosion resistance, hardness and wear resistance. It was also found that laser modification caused a slight deterioration of the properties in comparison with the diffusion borided layer. However, the laser modification process resulted in the production of a much thicker layer.

Microstructure and wear resistance of gas-nitrided steel after laser modification

2017 ◽  
Vol 1 (85) ◽  
pp. 12-20
Author(s):  
D. Panfil ◽  
M. Kulka ◽  
P. Wach ◽  
J. Michalski
Keyword(s):  
Wear Resistance ◽  
Laser Beam ◽  
Nitrided Layer ◽  
Beam Power ◽  
Surface Layers ◽  
Laser Modification ◽  
Gas Nitriding ◽  
Laser Heat ◽  
Laser Beam Power ◽  
Hybrid Layers

Purpose: The aim of this work was to study the microstructure and wear resistance of hybrid surface layers, produced by a controlled gas nitriding and laser modification. Design/methodology/approach: Nitriding is well-known method of thermo-chemical treatment, applied in order to produce surface layers of improved hardness and wear resistance. The phase composition and growth kinetics of the diffusion layer can be controlled using a gas nitriding with changeable nitriding potential. In this study, gas nitriding was carried out on 42CrMo4 steel at 570°C (843 K) for 4 hours using changeable nitriding potential in order to limit the thickness of porous e zone. Next, the nitrided layer was laser-modified using TRUMPF TLF 2600 Turbo CO2 laser. Laser tracks were arranged as the multiple tracks with scanning rate vl=2.88 m/min and overlapping of about 86% using the two laser beam powers (P): 0.21 kW and 0.26 kW. Microstructure was observed by an optical microscope. Phase composition was studied using XRD. Hardness profiles in the produced hybrid layers was determined using a Vickers method. Wera resistance tests were performed using MBT-01 tester. Findings: Gas nitriding resulted in formation of compound zone, consisting of e nitrides close to the surface and a zone, composed of e + g' nitrides. Below the white compound zone, the diffusion zone occurred with nitric sorbite and precipitates of g' nitrides. In the microstructure after laser heat treatment (LHT) of nitrided layer, the zones were observed as follows: the re-melted zone (MZ) with e nitrides, nitric martensite and non-equilibrium FeN0.056 phase, the heat-affected zone (HAZ) with nitric martensite and precipitates of g' phase and the diffusion zone (DZ) without visible effect of laser treatment. Laser beam power influenced the depth of MZ and HAZ, so the thickness of hardened zone. The hardness of MZ was slightly decreased compared to the hardness of compound zone after gas nitriding. However, the significant increase in hardness was observed in HAZ. The formation of hybrid layers advantageously influenced the tribological properties. The laser-heat treated nitrided layers were characterized by improved wear resistance compared to the only gas-nitrided layer. Research limitations/implications: The effect of LHT on the microstructure and properties of gas-nitrided layer was limited to the two laser beam powers. In the future research, this range should be exceeded, especially, taking into account the lower values of laser beam power. It will result in laser modification without re-melting. Practical implications: The selection of suitable LHT parameters could provide the hybrid layers of modified microstructure and improved wear resistance. Originality/value: This work was related to the new concept of modification of nitrided layer by laser heat treatment.

THE IRON BORIDE WEAR-RESISTANT LAYERS ON CONSTRUCTIONAL C45 STEEL, MODIFIED BY CHROMIUM AND THE LASER PROCESS

Tribologia ◽  
2016 ◽  
Vol 269 (5) ◽  
pp. 147-157
Author(s):  
Aleksandra PERTEK-OWSIANNA
Keyword(s):  
Wear Resistance ◽  
Eutectic Mixture ◽  
Constructional Steel ◽  
Second Step ◽  
Contact Method ◽  
Laser Modification ◽  
The Core ◽  
Frictional Wear ◽  
Two Stages ◽  
Hardness Gradient

The paper presents the influence of diffusional boronizing, borochromizing processes, and laser modification on microstructure, microhardness, and frictional wear resistance of C45 constructional steel. The borochromizing process consists of two stages: first the boronizing was applied, and then chromizing was carried out as a second step. The boronizing was performed at 900°C for 4h, and then chromizing at 1020°C for 7h using the gas-contact method in powder containing amorphous boron and ferrochrome. Then, the boronized and borochromized layer was modified by remelting it using a TRUMPH CO2 2600W-power laser. The microstructure after diffusional boronizing and borochromizing consists of needle-like iron borides with a thickness of 80 μm and 100 μm and with a microhardness of 1400 HV0.1–1850 HV0.1. Three zones are formed after laser modification: the remelted zone MZ (eutectic mixture of borides and martensite) with a thickness of 100–120 μm, a martensitic heat affected zone (HAZ), and the core. The microhardness in the remelted zone is approx. 1200 HV0.1, as a result of which there appears a milder hardness gradient between the surface and the core. It was found that the frictional wear resistance of the boride layers modified by chromium and laser is higher than that of the layers after diffusional boronizing.

scholarly journals Influence of Laser Cladding Parameters on Microstructure, Microhardness, Chemical Composition, Wear and Corrosion Resistance of Fe–B Composite Coatings Reinforced with B4C and Si Particles

Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 809 ◽  
Author(s):  
Dariusz Bartkowski ◽  
Aneta Bartkowska ◽  
Adam Piasecki ◽  
Peter Jurči
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Chemical Composition ◽  
Laser Beam ◽  
Laser Cladding ◽  
Scanning Speed ◽  
Powder Mixtures ◽  
Wear And Corrosion ◽  
Study Results ◽  
Wear And Corrosion Resistance

The paper presents the study results of a laser cladding process of C45 steel using powder mixtures. The aim of this study was to investigate the microstructure, X-ray diffraction (XRD), chemical composition (EDS), microhardness, corrosion resistance and wear resistance of the newly obtained coatings. Modified coatings were prepared using laser cladding technology. A 1 kW continuous wave Yb:YAG disk laser with a powder feeding system was applied. Two different powder mixtures as well as various laser beam parameters were used. The first powder mixture contained Fe–B, and the second mixture was Fe–B–B4C–Si. Two values of laser beam power (600 and 800 W) and three values of scanning speed (600, 800, and 1000 mm/min) were applied during the studies. As a result of the influence of the laser beam, the zones enriched with modifying elements were obtained. Based on the results of XRD, the presence of phases derived from borides and carbides was found. In all cases analyzed, EDS studies showed that there is an increased content of boron in the dendritic areas, while there is an increased silicon content in interdendritic spaces. The addition of B4C and Si improved properties such as microhardness as well as wear and corrosion resistance. The microhardness of the coating increased from approx. 400 HV to approx. 1100 HV depending on the laser parameters used. The best corrosion resistance was obtained for the Fe–B–B4C–Si coating produced using the highest laser beam scanning speed. An improvement in wear resistance can be seen after wear tests, where the weight loss decreased from about 0.08 g to about 0.05 g.

scholarly journals Synthesis of Functional Surface Layers on Stainless Steels by Laser Alloying

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 434
Author(s):  
Zoia Duriagina ◽  
Volodymyr Kulyk ◽  
Taras Kovbasiuk ◽  
Bogdan Vasyliv ◽  
Andrii Kostryzhev
Keyword(s):  
Wear Resistance ◽  
Stainless Steels ◽  
Liquid Glass ◽  
Scanning Speed ◽  
Laser Alloying ◽  
Functional Surface ◽  
Surface Layers ◽  
Aisi 304 ◽  
Aisi 420 ◽  
Phase Balance

Laser alloying is an effective method to form functional surface layers (coatings) on metallic materials, particularly on stainless steels. Unique phase balance, dislocation substructure, and a possibility to obtain gradient microstructures after laser alloying slow down the surface degradation and increase the wear resistance. In this work, the optimal parameters of laser alloying and their effects on microstructure and properties were investigated for two stainless steels: ferritic AISI 420 and austenitic AISI 304. Three types of alloying plasters were used: 85Nb + 15 graphite, 85Nb + 15 liquid glass, and 15Fe + 30Ni + 20B + 10Si + 25 liquid glass (wt.%). The laser power density of 0.3 × 105 W/cm2 and beam scanning speed of 1990 mm/min were found to generate 220–320 μm thick coatings with complex microstructures. Phase balance in the coatings was studied with X-ray diffraction and magnetometric phase analyses. High microhardness (up to 16 GPa) and wear resistance were associated with the formation of martensite with some retained austenite and Nb-, Cr-, Si-, and B-rich particles in the surface layer of AISI 420 steel, and high dislocation density austenite strengthened with Ti-, Nb-, Cr-, and Si-rich particles in AISI 304 steel.

scholarly journals Mechanical Properties of Nitrided Layer after Laser Modification

2021 ◽  
Vol 8 (1) ◽  
pp. 1-6
Author(s):  
Dominika Panfil-Pryka ◽  
Michał Kulka
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Nitrided Layer ◽  
Wear Testing ◽  
Surface Layers ◽  
Laser Modification ◽  
Gas Nitriding ◽  
Large Fluctuations ◽  
42Crmo4 Steel ◽  
Hybrid Layers

The aim of this work was to study the microstructure and friction coefficient of hybrid surface layers, produced by a controlled gas nitriding and laser modification. Nitriding is well-known technique of thermo-chemical treatment, applied in order to produce the surface layers of improved hardness and wear resistance. The phase composition and growth kinetics of the diffusion layer can be controlled using a gas nitriding with changeable nitriding potential. 42CrMo4 steel was treated by composite technology of gas nitriding and laser hardening. The nitriding processes were carried out at temperature of 580 °C for 8h. Next, the nitrided layer was laser-modified using laser TRUMPF TruDiode 3006 with maximal power of 3 kW using the two laser beam powers (P): 0.53 kW and 0.62 kW. Then, the microstructure and properties of the laser-modified nitrided layers were investigated using optical microscopy, Vickers hardness tester and friction wear testing machine. The nitrided layers were subjected to wear tests using a ball-on-disc method at room temperature. The results showed that the microstructure of the produced hybrid layers consisted of the re-melted and heat-affected zones in which martensite mainly occurred. Additional laser treatment effectively increased the hardness, especially in heat-affected zone, as well as the depth of the hardened layer. The layer after modification laser hest tretment were good friction coefficien. The curve of the friction coefficient after the nitrided layer was characterized by large fluctuations. Compared with nitriding technology , the hybrid treatment technology can effectively increase the hardness and wear resistance of the 42CrMo4 steel surface. The effect of LHT on the tribological properties was ambiguous. Although the relatively low value of the average friction coefficient (0.46) was calculated for nitrided layer, the course of friction coefficient was characterized by large fluctuations and the extended grinding-in time. Simultaneously, the course of friction coefficient was very smooth after nitriding and LHT. However, the average friction coefficient were higher, obtaining 0.60 and 0.57 for the hybrid layers, produced using P=530 W and P=620 W, respectively. Keywords: Nitriding; Laser Heat Treatment; Microstructure; Wear Resistance; Microhardness

scholarly journals Growth Kinetics and Some Mechanical Properties of Plasma Paste Borided Layers Produced on Nimonic 80A-Alloy

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5146
Author(s):  
Natalia Makuch ◽  
Piotr Dziarski ◽  
Michał Kulka ◽  
Mourad Keddam
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Growth Kinetics ◽  
High Hardness ◽  
Gas Mixture ◽  
Processing Temperature ◽  
Surface Layers ◽  
Nimonic 80A ◽  
Boron Source ◽  
Plasma Paste Boriding

Plasma paste boriding was employed in order to produce the boride layers on Nimonic 80A-alloy. The process was carried out at temperatures of 1023 K, 1073 K and 1123 K for 3, 4 and 6 h in a gas mixture of 50% H2-50% Ar. Borax paste was used as a boron source. The microstructure of the produced surface layers consisted of the mixture of nickel borides and chromium borides. The effect of processing temperature and duration on the thickness of the borided layers was observed. The theoretical thicknesses of the borided layers were estimated using an integral diffusion model. A good correlation was obtained between the theoretical (modeled) and experimental depths of the plasma paste borided layers. The boride layers were characterized by a high hardness ranging from 1160 HV to 2132 HV. The multiphase character of the produced layers resulted in differences in hardness. A significant improvement of the wear resistance of the plasma paste borided Nimonic 80A-alloy was observed in comparison with the non-borided alloy.

scholarly journals Pulsed UV Laser Processing of Carbosilane and Silazane Polymers

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 372 ◽  
Author(s):  
Samuel Ligon ◽  
Gurdial Blugan ◽  
Jakob Kuebler
Keyword(s):  
Laser Beam ◽  
Laser Processing ◽  
Scanning Speed ◽  
Inert Atmosphere ◽  
Laser Wavelength ◽  
Uv Laser ◽  
Glass Substrates ◽  
Polymer Precursors ◽  
Laser Systems ◽  
Pre Treatment

Freestanding SiCNO ceramic pieces with sub-mm features were produced by laser crosslinking of carbosilane and silazane polymer precursors followed by pyrolysis in inert atmosphere. Three different pulsed UV laser systems were investigated, and the influence of laser wavelength, operating power and scanning speed were all found to be important. Different photoinitiators were tested for the two lasers operating at 355 nm, while for the 266 nm laser, crosslinking occurred also without photoinitiator. Pre-treatment of glass substrates with fluorinated silanes was found to ease the release of green bodies during solvent development. Polymer crosslinking was observed with all three of the laser systems, as were bubbles, surface charring and in some cases ablation. By focusing the laser beam several millimeters above the surface of the resin, selective polymer crosslinking was observed exclusively.

scholarly journals Effect of Laser Parameters on Sequential Laser Beam Micromachining and Micro Electro-Discharge Machining

2021 ◽  
Author(s):  
Mir Akmam Noor Rashid ◽  
Tanveer Saleh ◽  
Wazed Ibne Noor ◽  
Mohamed Sultan Mohamed Ali
Keyword(s):  
Laser Beam ◽  
Laser Power ◽  
Short Circuit ◽  
Scanning Speed ◽  
Hole Drilling ◽  
Machining Time ◽  
Research Attention ◽  
Pilot Hole ◽  
Electro Discharge Machining ◽  
Input Parameters

Abstract Laser beam micromachining (LBMM) and micro electro-discharge machining (µEDM) based sequential micromachining technique, LBMM-µEDM has drawn significant research attention to utilizing the advantages of both methods, i.e. LBMM and µEDM. In this process, a pilot hole is machined by the LBMM and subsequently finishing operation of the hole is carried out by the µEDM. This paper presents an experimental investigation on the stainless steel (type SS304) to observe the effects of laser input parameters (namely laser power, scanning speed, and pulse frequency) on the performance of the finishing technique that is the µEDM in this case. The scope of the work is limited to 1-D machining, i.e. drilling micro holes. It was found that laser input parameters mainly scanning speed and power influenced the output performance of µEDM significantly. Our study suggests that if an increased scanning speed at a lower laser power is used for the pilot hole drilling by the LBMM process, it could result in significantly slower µEDM machining time. On the contrary, if the higher laser power is used with even the highest scanning speed for the pilot hole drilling, then µEDM processing time was faster than the previous case. Similarly, µEDM time was also quicker for LBMMed pilot holes machined at low laser power and slow scanning speed. Our study confirms that LBMM-µEDM based sequential machining technique reduces the machining time, tool wear and instability (in terms of short circuit count) by a margin of 2.5 x, 9 x and 40 x respectively in contrast to the pure µEDM process without compromising the quality of the holes.

Modelling of laser cladding of medium carbon steel - a first approach

2004 ◽  
Vol 120 ◽  
pp. 405-412
Author(s):  
J. Ahlström ◽  
B. Karlsson ◽  
S. Niederhauser
Keyword(s):  
Carbon Steel ◽  
Laser Beam ◽  
Laser Cladding ◽  
Rapid Heating ◽  
Current Model ◽  
Substrate Material ◽  
Medium Carbon Steel ◽  
Medium Carbon ◽  
Heating And Cooling ◽  
Railway Wheels

A model on laser cladding of medium carbon steel, used in railway wheels and rails, is developed and implemented. When the laser beam is scanned over the surface during the cladding operation, phase transformations occur in the topmost layer of the substrate material due to rapid heating and cooling. The hardened regions may later be annealed, either during subsequent passes of the laser beam or by for example induction heating. The current model is a first step towards judging the resulting microstructure and hardness in the heat affected zone under the clad.

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