scholarly journals Research study of the elastic-strength and tribological characteristics of the surface after laser processing of the slurry coatings

2021 ◽  
Vol 2131 (5) ◽  
pp. 052032
Author(s):  
E Vasilkova ◽  
Ph Myasnikov ◽  
N Myasnikova
Keyword(s):  
Laser Processing ◽  
Base Material ◽  
Steel Sample ◽  
Tribological Characteristics ◽  
Surface Layers ◽  
Slurry Coating ◽  
Modified Surface ◽  
Laser Impact ◽  
Elastic And Plastic Deformation ◽  
Composite Slurry

Abstract The research paper examines the results of applying the proposed method of the laser processing of the composite slurry coating on the steel samples` surface such as 12Kh2N4A-Sh. An increase in the elastic-strength and tribological characteristics` surface occurs as a result of the imposition of several physicochemical processes in the laser-impact zone on the applied composite slurry coating with an epoxy element as the base material with the laser thermal hardening, the diffusion influence on the atomic boron along grain boundaries, carbonization and the formation of a modified surface layer. The conducted research shows the gradient structure of the surface layers. The coating composition varies in the studied samples, however, for all experimental samples, the elastic-strength and tribological characteristics are higher than the corresponding characteristics of the standard steel sample as 12Kh2N4A-Sh, which has undergone the cementation process. The calculated values of the resistance indicators of the elastic and plastic deformation are confirmed by the conducted tribological tests. It is given the higher efficiency of the laser processing method of the slurry coating and it is concluded the prospects of the proposed method.

scholarly journals Surface Modification of a Nickel-Free Austenitic Stainless Steel by Low-Temperature Nitriding

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1845
Author(s):  
Francesca Borgioli ◽  
Emanuele Galvanetto ◽  
Tiberio Bacci
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Low Temperature ◽  
Stainless Steels ◽  
Volume Fraction ◽  
Surface Hardness ◽  
Austenitic Stainless Steels ◽  
Surface Layers ◽  
Modified Surface

Low-temperature nitriding allows to improve surface hardening of austenitic stainless steels, maintaining or even increasing their corrosion resistance. The treatment conditions to be used in order to avoid the precipitation of large amounts of nitrides are strictly related to alloy composition. When nickel is substituted by manganese as an austenite forming element, the production of nitride-free modified surface layers becomes a challenge, since manganese is a nitride forming element while nickel is not. In this study, the effects of nitriding conditions on the characteristics of the modified surface layers obtained on an austenitic stainless steel having a high manganese content and a negligible nickel one, a so-called nickel-free austenitic stainless steel, were investigated. Microstructure, phase composition, surface microhardness, and corrosion behavior in 5% NaCl were evaluated. The obtained results suggest that the precipitation of a large volume fraction of nitrides can be avoided using treatment temperatures lower than those usually employed for nickel-containing austenitic stainless steels. Nitriding at 360 and 380 °C for duration up to 5 h allows to produce modified surface layers, consisting mainly of the so-called expanded austenite or gN, which increase surface hardness in comparison with the untreated steel. Using selected conditions, corrosion resistance can also be significantly improved.

scholarly journals Effect of Preliminary Irradiation of 321 Steel Substrates with High-Intense Pulsed Ion Beams on Scratch Test Results of Subsequently Deposited AlN Coatings

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1169
Author(s):  
Vladislav Tarbokov ◽  
Sergey Pavlov ◽  
Egor Smolyanskiy ◽  
Vladimir Uglov ◽  
Mikhail Slobodyan ◽  
...  
Keyword(s):  
Ion Beam ◽  
Energy Levels ◽  
Scratch Test ◽  
Future Research ◽  
Surface Layers ◽  
Emission Signal ◽  
Future Research Directions ◽  
Modified Surface ◽  
Scratch Tests ◽  
Steel Substrates

The paper presents the effect of irradiation of 321 steel substrates with a high-intense pulsed ion beam (HIPIB) on changes in functional properties of the surface layers and tribological characteristics of AlN coatings subsequently deposited above by the reactive magnetron sputtering method. The morphology of the modified surface layers, their microhardness and free surface energy levels are presented for different HIPIB energy densities. HIPIB irradiation of the substrates caused variations in the results of scratch tests combined with the acoustic emission signal processing. Their analysis has enabled concluding that the crack initiation threshold could be at least doubled for the studied coating/substrate system due to preliminary HIPIB irradiation. Finally, the obtained data were discussed, and future research directions were proposed.

In Situ Produced MMC Layer by Laser Melt Injection

2010 ◽  
Vol 649 ◽  
pp. 61-66
Author(s):  
Zoltán Kálazi ◽  
Viktória Janó ◽  
Gábor Buza
Keyword(s):  
Carbon Content ◽  
Composite Layer ◽  
Pure Titanium ◽  
Base Material ◽  
Titanium Content ◽  
Steel Sample ◽  
Low Carbon ◽  
The Matrix ◽  
Ti Powder

Tungsten (W) based alloy composite layer reinforced with TiC particles has been successfully prepared on unalloyed steel sample by LMI technology. In order to obtain in situ produced TiC reinforcement, pure titanium has been introduced to the melt pool. WC powder was added for increasing the carbon content of the layer in order to avoid the softening of the matrix (with low carbon content) during TiC formation. The present study aims to investigate the optimum amount of injected WC and Ti powder to improve wear resistance and hardness of the layer. Samples were investigated using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The maximum hardness of the layer has been reached ~900HV in case of 2-4wt% of titanium content. Ti has been collected all of the carbon from the matrix when titanium content was 9,6wt%, which resulted that the austenite and (Fe,W)6C phases have been disappeared. Only α-Fe and TiC phases were presented in the layer. The hardness of the layer reduced to the hardness of the base material.

Properties of modified surface layers of industrial steel samples processed by pulsed plasma streams

Vacuum ◽  
2000 ◽  
Vol 58 (2-3) ◽  
pp. 195-201 ◽  
Author(s):  
I.E. Garkusha ◽  
O.V. Byrka ◽  
V.V. Chebotarev ◽  
N.T. Derepovski ◽  
G. Müller ◽  
...  
Keyword(s):  
Pulsed Plasma ◽  
Surface Layers ◽  
Modified Surface

Study on the friction characteristics of 304 steel with composite surface modification

2017 ◽  
Vol 69 (2) ◽  
pp. 248-258 ◽  
Author(s):  
Wengang Chen ◽  
Xueyuan Liu ◽  
Lili Zheng
Keyword(s):  
Surface Modification ◽  
Friction And Wear ◽  
Steel Surface ◽  
Testing Machine ◽  
Wear Testing ◽  
Tribological Characteristics ◽  
Textured Surface ◽  
Content Type ◽  
Good Basis ◽  
Modified Surface

Purpose This paper aims to clarify the friction properties of 304 steel surface modification. The surface modification includes laser texturing processing and nitriding treatment on 304 steel surface, and then the friction properties’ test was conducted on different friction directions and different upper test samples by using microfriction and wear testing machine. Design/methodology/approach The diameter and spacing of 100-, 150-, 200-, 300-μm pit array on the surface of 304 steel were calculated using a M-DPSS-50 semiconductor laser device. Then, the textured surface was nitriding-treated using a nitriding salt bath device. The chemical composition, surface morphology and surface microhardness of the composite-modified surface were measured by X-ray diffraction and by using an optical microscope and a microhardness tester. The tribological characteristics of the composite-modified surface were tested by MRTR microcomputer-controlled multifunctional friction and wear testing machine. Findings The result showed that a rule pit texture surface was obtained by the texture processing. The microhardness of nitriding treatment surface reached 574.27HV0.1, which significantly higher than 222.58HV0.1 of 304 steel. The composite-modified surface has excellent anti-friction and wear resistance properties when the upper specimen was GCr15 steel and ZrO2, respectively. The composite-modified surface has excellent anti-friction and anti-wear properties after long time friction under different angles. However, the friction coefficient and wear morphology of the friction pairs are not affected by the friction angle. Research limitations/implications Because of the chosen research approach, the research results may lack generalizability. Therefore, researchers are encouraged to test the proposed propositions further. Practical implications The paper conducted a systematic study of the tribological characteristics of 304 steel composite modification surface and provided a good basis for the extensive application of 304 steel. Social implications The study provides a good basis for the extensive application of 304 steel. Originality/value This paper fulfils an identified need to study the extensive application of 304 steel.

scholarly journals Characterization of the Surface Layer of Mg Enriched with Al and Si by Thermochemical Treatment

2017 ◽  
Vol 17 (4) ◽  
pp. 195-199 ◽  
Author(s):  
R. Mola ◽  
E. Stępień ◽  
M. Cieślik
Keyword(s):  
Solid Solution ◽  
Thermochemical Treatment ◽  
Heating Time ◽  
Substrate Material ◽  
Surface Layers ◽  
X Ray ◽  
Three Phase ◽  
Distribution Of Elements ◽  
Modified Surface

AbstractThe modified surface layers of Mg enriched with Al and Si were fabricated by thermochemical treatment. The substrate material in contact with an Al + 20 wt.% Si powder mixture was heated to 445°C for 40 or 60 min. The microstructure of the layers was examined by OM and SEM. The chemical composition of the layer and the distribution of elements were determined by energy dispersive X-ray spectroscopy (EDS). The experimental results show that the thickness of the layer is dependent on the heating time. A much thicker layer (1 mm) was obtained when the heating time was 60 min than when it was 40 min (600 μm). Both layers had a non-homogeneous structure. In the area closest to the Mg substrate, a thin zone of a solid solution of Al in Mg was detected. It was followed by a eutectic with Mg17Al12and a solid solution of Al in Mg. The next zone was a eutectic with agglomerates of Mg2Si phase particles; this three-phase structure was the thickest. Finally, the area closest to the surface was characterized by dendrites of the Mg17Al12phase. The microhardness of the modified layer increased to 121-236 HV as compared with 33-35 HV reported for the Mg substrate.

Rapidly Solidified Microstructure in Surface Layers of Laseralloyed Mo on Fe-C Substrates

1981 ◽  
Vol 8 ◽  
Author(s):  
T. R. Tucker ◽  
A. H. Clauer ◽  
S. L. Ream ◽  
C. T. Walters
Keyword(s):  
Continuous Wave ◽  
Base Material ◽  
Laser Beams ◽  
Continuous Wave Laser ◽  
Surface Layers ◽  
Spray Process ◽  
Plasma Spray Process ◽  
Heat Effects ◽  
Rapidly Solidified ◽  
Original Coating

ABSTRACTShaped continuous-wave laser beams have been used to alloy molybdenum coatings into Fe-C substrates. The Mo overlay was first deposited by the plasma spray process in an inert gas environment. Slowly scanned laser radiation then melted a layer 2 to 5 times the thickness of the original Coating causing the two metallic species to mix. Melt proceeded from the coating/substrate interface, the Mo melt temperatures being significantly higher than that of the base material. Fusion zone microstructures for individual melt passes appeared to be homogeneous, and molybdenum composition was found to be relatively uniform. With overlapping melt passes, the microstructures became more complex with heat effects apparent in the overlap regions.

scholarly journals Electron Microscopic Characterization of Mechanically Modified Surface Layers of Deep Rolled Steel

Procedia CIRP ◽  
2016 ◽  
Vol 45 ◽  
pp. 367-370 ◽  
Author(s):  
L. Ehle ◽  
J. Kämmler ◽  
D. Meyer ◽  
A. Schwedt ◽  
J. Mayer
Keyword(s):  
Rolled Steel ◽  
Surface Layers ◽  
Electron Microscopic ◽  
Modified Surface
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