scholarly journals Residual Stresses on Various PVD Hard Coatings on Tube and Plate Substrates

Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1054
Author(s):  
Harri Lille ◽  
Alexander Ryabchikov ◽  
Priidu Peetsalu ◽  
Liina Lind ◽  
Fjodor Sergejev ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Rear Surface ◽  
Front Surface ◽  
Length Change ◽  
Hard Coatings ◽  
Wear Testing ◽  
Tube Length ◽  
Length Variation ◽  
Cross Sectional ◽  
Compressive Residual Stresses

In this study, the average residual stresses were determined in hard PVD nACRo (nc-AlCrN/a-Si3N4), nACo (nc-AlTiN/a-Si3N4), AlCrN, TiAlN, and TiCN commercial coatings through the deflection of the plate substrates and the simultaneous measurement of length variation in thin-walled tubular substrates. The length measuring unit was used for the measurement of any length change in the tubular substrate. A change in tube length was reduced to the deflection of the middle cross-section of the elastic element for which deformation was measured using four strain gauges. The cross-sectional microstructure and thickness of the coatings were investigated by means of scanning electron microscopy (SEM), and a determination was made of the chemical composition of the coatings and substrate by means of energy dispersive X-ray spectroscopy (EDS). The values of average compressive residual stresses, as determined by both methods, were very high (with a variation of between 2.05 and 6.63 GPa), irrespective of coating thickness, but were dependent upon the shape of the substrate and on its position in relation to the axis of the rotating cathode. The thicknesses of the coatings that were deposited on the plates with two parallel fixings (such as the nACRo coatings on the front surface at 6.8 μm and on the rear surface at 2.9 μm) and on the tubular substrates (10.0 μm) were significantly different. The higher average compressive residual stresses in the coating correlate to the higher average relative wear resistance that was obtained during field wear testing.

Average Residual Stresses in Hard Physical Vapor Deposited (PVD) Coatings

2019 ◽  
Vol 799 ◽  
pp. 20-25
Author(s):  
Harri Lille ◽  
Alexander Ryabchikov ◽  
Jakub Kõo ◽  
Valdek Mikli ◽  
Eron Adoberg ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Front Surface ◽  
Back Surface ◽  
Length Variation ◽  
Pvd Coatings ◽  
Cross Sectional ◽  
Average Residual ◽  
Thin Walled ◽  
Compressive Residual Stresses ◽  
Very High

In this study we determined average residual stresses in hard nitride PVD AlCrN, TiAlN and TiCN coatings through simultaneous measurement of length variation in thin-walled tubular substrates and of the curvature of plate substrates. A device for measurement of the length of the tube was developed. Inside the depositing chamber the tube and the plate were fixed parallel in the relation to the axis of the rotating cathode. One batch of plate samples was produced by deposition on front surface (facing the cathode) and the other batch, by deposition on back surface (with back to the cathode). The cross-sectional microstructure and thickness of the coatings were investigated by means of scanning electron microscopy (SEM). The thicknesses of the coatings deposited on front and back surfaces of the plates and on the tube were significantly different. The values of average compressive residual stresses, determined by both methods, were very high irrespective of coating thickness. It was found that the values of compressive residual stresses in the coating were dependent on the shape of the substrate and on its position in the relation to the axis of the rotating cathode.

Evaluation of Residual Stresses in PVD Coatings by Means of Strip Substrate Length Variation and Curvature Method of Plate Substrate

2017 ◽  
Vol 267 ◽  
pp. 212-218 ◽  
Author(s):  
Harri Lille ◽  
Alexander Ryabchikov ◽  
Jakub Kõo ◽  
Eron Adoberg ◽  
Liina Lind ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Length Change ◽  
Steel Plates ◽  
Length Variation ◽  
Pvd Coatings ◽  
Compressive Stresses ◽  
Steel Strips ◽  
Middle Cross Section ◽  
Method Strip

The aim of the study was to determine macroscopic residual stresses in Physical Vapor Deposits (PVD) coatings through measurement of the length variation of the strip substrates coated on both sides. The length change of the strip was reduced to the deflection of the middle cross-section of the elastic element and was recorded by four strain gauges. For validating the obtained results, the conventional curvature method was used. As an application, residual stresses in hard AlCrN PVD coatings were investigated. The coatings were nanolayered to achieve better coating toughness for blanking and punching applications. The steel strips and steel plates with two thicknesses were used as the substrate. The values of the compressive residual stresses, determined by both methods for the investigated coatings, were very high (3.3 -3.6 GPa) independent of coating thickness and practically equal within the measurement uncertainty of the method. Good agreement between the experimental results obtained with both methods suggests that the presented method, strip length variation, is applicable for determination of residual stresses in coatings. Compressive stresses in coatings are desirable as they strengthen the coating.

Comparative Tribological Behavior of V(N,C) and VC Diffusion Coatings

2010 ◽  
Vol 297-301 ◽  
pp. 1183-1189
Author(s):  
F. Fazlalipour ◽  
M. Niki Nushari ◽  
N. Shakib ◽  
Ali Shokuhfar
Keyword(s):  
Surface Morphology ◽  
Wear Mechanisms ◽  
Hard Coatings ◽  
Wear Testing ◽  
Reactive Diffusion ◽  
Chemical System ◽  
Uniform Structure ◽  
Morphological Examination ◽  
Cross Sectional ◽  
Pin On Disk

Hard coatings show various tribological behaviors against different contact materials (counter-faces) during dry sliding depended on their microstructure, surface morphology and encountered tribological systems and condition. In this work, the tribological and wear mechanisms of vanadium carbide (VC) and vanadium nitrocarbide (V(N,C)) layers were examined against WC/Co cemented tungsten carbide pin during pin-on-disk sliding wear testing. The V(N,C) layer was produced by a duplex surface treatment involving the gas pre-nitrocarburising followed by thermo-reactive diffusion (TRD) vanadizing technique. The coating layers were characterized by a cross sectional and morphological examination methods and X-ray diffraction analysis to identify damages of the coating’s surface. Wear mechanisms were determined by SEM microscope in BSI and SE mode accompanied by EDS analysis. Results revealed that the surface morphology of the V(N,C) coating consist of dense and smooth layer in comparison with the VC coating surface which reveals a non-uniform structure with chasms. It was determined that the activation of tribo-chemical system and oxidizing of the coating layer together with minor plastic deformation are the dominant wear mechanism in the V(N,C) coated steel. In the case of the VC coating, combination of abrasive wear and adhesion of pin material to coating and vice versa are the major impairing mechanisms.

TEM sample preparation of wear-tested room-temperature pulsed-laser-deposited thin films of MoS2 by ultramicrotomy

1993 ◽  
Vol 51 ◽  
pp. 1118-1119
Author(s):  
Pamela F. Lloyd ◽  
Scott D. Walck
Keyword(s):  
Thin Films ◽  
Sample Preparation ◽  
Room Temperature ◽  
High Vacuum ◽  
Pulsed Laser ◽  
Ultra High Vacuum ◽  
Wear Testing ◽  
Preparation Technique ◽  
Cross Sectional ◽  
Aerospace Applications

Pulsed laser deposition (PLD) is a novel technique for the deposition of tribological thin films. MoS2 is the archetypical solid lubricant material for aerospace applications. It provides a low coefficient of friction from cryogenic temperatures to about 350°C and can be used in ultra high vacuum environments. The TEM is ideally suited for studying the microstructural and tribo-chemical changes that occur during wear. The normal cross sectional TEM sample preparation method does not work well because the material’s lubricity causes the sandwich to separate. Walck et al. deposited MoS2 through a mesh mask which gave suitable results for as-deposited films, but the discontinuous nature of the film is unsuitable for wear-testing. To investigate wear-tested, room temperature (RT) PLD MoS2 films, the sample preparation technique of Heuer and Howitt was adapted.Two 300 run thick films were deposited on single crystal NaCl substrates. One was wear-tested on a ball-on-disk tribometer using a 30 gm load at 150 rpm for one minute, and subsequently coated with a heavy layer of evaporated gold.

Cross-sectional Mapping of Residual Stresses Using the Contour Method

2019 ◽  
Vol 88 (6) ◽  
pp. 472-475
Author(s):  
Daisuke TAKAKURA ◽  
Hiroshi FUKAZAWA ◽  
Mitsuyoshi TSUNORI
Keyword(s):  
Residual Stresses ◽  
Contour Method ◽  
Cross Sectional

scholarly journals X-ray Determination of Compressive Residual Stresses in Spring Steel Generated by High-Speed Water Quenching

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1154
Author(s):  
Diego E. Lozano ◽  
George E. Totten ◽  
Yaneth Bedolla-Gil ◽  
Martha Guerrero-Mata ◽  
Marcel Carpio ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Residual Stresses ◽  
High Speed ◽  
Spring Steel ◽  
X Ray Diffraction ◽  
Laboratory Equipment ◽  
X Ray ◽  
Water Chamber ◽  
Hardened Case ◽  
Compressive Residual Stresses

Automotive components manufacturers use the 5160 steel in leaf and coil springs. The industrial heat treatment process consists in austenitizing followed by the oil quenching and tempering process. Typically, compressive residual stresses are induced by shot peening on the surface of automotive springs to bestow compressive residual stresses that improve the fatigue resistance and increase the service life of the parts after heat treatment. In this work, a high-speed quenching was used to achieve compressive residual stresses on the surface of AISI/SAE 5160 steel samples by producing high thermal gradients and interrupting the cooling in order to generate a case-core microstructure. A special laboratory equipment was designed and built, which uses water as the quenching media in a high-speed water chamber. The severity of the cooling was characterized with embedded thermocouples to obtain the cooling curves at different depths from the surface. Samples were cooled for various times to produce different hardened case depths. The microstructure of specimens was observed with a scanning electron microscope (SEM). X-ray diffraction (XRD) was used to estimate the magnitude of residual stresses on the surface of the specimens. Compressive residual stresses at the surface and sub-surface of about −700 MPa were obtained.

scholarly journals Thermal Effects on Surface and Subsurface Modifications in Laser-Combined Deep Rolling

2021 ◽  
Vol 5 (2) ◽  
pp. 55
Author(s):  
Robert Zmich ◽  
Daniel Meyer
Keyword(s):  
Surface Layer ◽  
Residual Stresses ◽  
Thermal Loads ◽  
Deep Rolling ◽  
Mechanical Loads ◽  
Thermomechanical Process ◽  
Compressive Stresses ◽  
New Process ◽  
Negative Effect ◽  
Compressive Residual Stresses

Knowledge of the relationships between thermomechanical process loads and the resulting modifications in the surface layer enables targeted adjustments of the required surface integrity independent of the manufacturing process. In various processes with thermomechanical impact, thermal and mechanical loads act simultaneously and affect each other. Thus, the effects on the modifications are interdependent. To gain a better understanding of the interactions of the two loads, it is necessary to vary thermal and mechanical loads independently. A new process of laser-combined deep rolling can fulfil exactly this requirement. The presented findings demonstrate that thermal loads can support the generation of residual compressive stresses to a certain extent. If the thermal loads are increased further, this has a negative effect on the surface layer and the residual stresses are shifted in the direction of tension. The results show the optimum range of thermal loads to further increase the compressive residual stresses in the surface layer and allow to gain a better understanding of the interactions between thermal and mechanical loads.

scholarly journals Additive Manufactured 316L Stainless-Steel Samples: Microstructure, Residual Stress and Corrosion Characteristics after Post-Processing

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 182
Author(s):  
Suvi Santa-aho ◽  
Mika Kiviluoma ◽  
Tuomas Jokiaho ◽  
Tejas Gundgire ◽  
Mari Honkanen ◽  
...  
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Sample Surface ◽  
Post Processing ◽  
Magnesium Chloride Solution ◽  
Manufacturing Method ◽  
Four Point Bending ◽  
Traditional Manufacturing ◽  
Processing Steps ◽  
Compressive Residual Stresses

Additive manufacturing (AM) is a relatively new manufacturing method that can produce complex geometries and optimized shapes with less process steps. In addition to distinct microstructural features, residual stresses and their formation are also inherent to AM components. AM components require several post-processing steps before they are ready for use. To change the traditional manufacturing method to AM, comprehensive characterization is needed to verify the suitability of AM components. On very demanding corrosion atmospheres, the question is does AM lower or eliminate the risk of stress corrosion cracking (SCC) compared to welded 316L components? This work concentrates on post-processing and its influence on the microstructure and surface and subsurface residual stresses. The shot peening (SP) post-processing levelled out the residual stress differences, producing compressive residual stresses of more than −400 MPa in the AM samples and the effect exceeded an over 100 µm layer below the surface. Post-processing caused grain refinement and low-angle boundary formation on the sample surface layer and silicon carbide (SiC) residue adhesion, which should be taken into account when using the components. Immersion tests with four-point-bending in the heated 80 °C magnesium chloride solution for SCC showed no difference between AM and reference samples even after a 674 h immersion.

Ultrasonic Evaluation of Compressive Residual Stress of Surface Treated Metals

2005 ◽  
Vol 490-491 ◽  
pp. 184-189 ◽  
Author(s):  
Farid Belahcene ◽  
Xiaolai Zhou ◽  
Jian Lu
Keyword(s):  
Experimental Data ◽  
Residual Stresses ◽  
Nondestructive Evaluation ◽  
Subsurface Layer ◽  
Surface Mechanical Attrition Treatment ◽  
Shallow Subsurface ◽  
Ultrasonic Evaluation ◽  
Mechanical Attrition ◽  
Machine Parts ◽  
Compressive Residual Stresses

Shot peening is an effective method of improving fatigue performance of machine parts in the industry by producing a thin surface layer of compressive residual stresses that prevents crack initiation and retards crack growth during service. Nondestructive evaluation of the prevailing compressive residual stresses in the shallow subsurface layer is realized by the critically refracted longitudinal (Lcr) waves. This paper presents experimental data obtained on SMAT (surface mechanical attrition treatment) steel alloy S355 sample. Comparative travel-time shows that there are statistically significant differences in treated and untreated specimen. With knowledge of the acoustoelastic constants which are obtained by a test calibration, the experimental data indicates that compressive residual stresses are distributed near subsurface (hundreds of micron). These stress results show that the Lcr technique is efficient for evaluation of residual stresses after the surface treatment.

The Residual Stresses Generated by Deep Rolling and their Stability in Fatigue & Application to Deep-Rolled Crankshafts

2006 ◽  
Vol 524-525 ◽  
pp. 45-50 ◽  
Author(s):  
H. Michaud ◽  
Jean Michel Sprauel ◽  
F. Galzy
Keyword(s):  
Residual Stresses ◽  
Fatigue Resistance ◽  
Experimental Validation ◽  
Crack Arrest ◽  
Cyclic Fatigue ◽  
Rolling Process ◽  
Fatigue Behaviour ◽  
Deep Rolling ◽  
Bending Fatigue ◽  
Compressive Residual Stresses

In this work, the effect of steel grade on the fatigue resistance of deep-rolled crankshafts is analysed. In the first part of this paper, the mechanisms leading to the increase of the fatigue resistance brought by the deep rolling treatment, is presented. This reinforcement is mainly linked to crack arrest due both to a decrease of the in-depth stress concentration factor and to remaining compressive residual stresses induced by the deep rolling. In a second part, an analytical model of residual stresses generation by deep-rolling and fatigue is presented. In this model the low cyclic fatigue behaviour of the steel is taken into account, and the residual stress stability with bending fatigue cycling can be predicted. After a presentation of the experimental validation on two different microstructures (baintic and ferrito- perlitic), this model is used for analysing the main parameters of the deep-rolling process and fatigue resistance.

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