Influence of Combined Mechanical Processes on Tribological Properties of Tool Steels Vanadis 8 and Vancron 40 With a Similar Hardness

Surface integrity is important factor for components exposed to wear, like cold working tools, which need to possess high hardness combined with high wear resistance. Surface treatments such as grinding, hard turning, and hard turning with slide burnishing have been developed for its improvement. Vancron 40 and Vanadis 8 tool steels, of different chemical composition and different types and amounts of carbides, were now investigated. Heat treatment was carried out in vacuum furnaces with gas quenching to hardness of Vancron 64 ± 1 HRC and of Vanadis 65 ± 1 HRC. 3D topography, optical and scanning electron microscopy, X-ray diffraction and ball-on-disc tribological tests against Al2O3 and 100Cr6 balls as counterparts were used to examine wear and friction. For both steels, the lowest values of dynamic frictions and wear rates against Al2O3 counterbodies were achieved after sequential process of hard turning with slide burnishing with a burnishing force of 180 N. For alumina balls, the increase of wear resistance, achieved after hard turning plus burnishing in comparison to grinding exceeds 50 and 60%, respectively for Vanadis 8 and Vancron 40 steels.

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Impact of Mechanical Processes as a Pre-Sulphonitriding Treatment on Tribology Properties of Selected P/M Tool Steels

Materials ◽

10.3390/ma12203431 ◽

2019 ◽

Vol 12 (20) ◽

pp. 3431 ◽

Cited By ~ 1

Author(s):

Daniel Toboła

Keyword(s):

Wear Resistance ◽

Cross Sections ◽

Tool Steels ◽

X Ray Diffraction ◽

Wear Rates ◽

Different Types ◽

Pin On Disc ◽

Slide Burnishing ◽

Gas Quenching ◽

Vacuum Furnaces

We have evaluated phase composition changes in the surface layer (SL) and wear resistance of steels investigated after various mechanical processes such as a pre-sulphonitriding treatments. Two various paths of surface modification were employed: Grinding–sulphonitriding (G-SN) and hard turning–slide burnishing–sulphonitriding (T-B-SN). Studies were carried out on Vanadis 8 and Vancron 40 tool steels, which are classified as advanced powder metallurgy (P/M) high-alloyed steels with different types and amounts of carbides. Heat treatment to the final hardness of 64 ± 1 HRC (Vanadis 8) and 62 ± 1 HRC (Vancron 40) was performed in vacuum furnaces with gas quenching. Precipitation of different types such as sulfides, nitrides, and carbides was observed using X-ray diffraction analysis. Tribological properties of SL were evaluated by pin-on-disc experiments. Pins of Al2O3 and 19MnB4 steel were used as counterbodies materials. 3D surface geometrical structure measurements were also performed. Wear tracks and cross-sections of SL were observed using optical and scanning electron microscopy. The three-stage process increases the wear resistance about 37% and 30%, respectively for Vanadis 8 and Vancron 40 (in case of alumina pins), whereas values of wear rates after tests performed against steel pins were very similar for two compared processes for both steels.

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Selected properties of Vanadis 8 tool steel after grinding and hard turning

Mechanik ◽

10.17814/mechanik.2017.10.129 ◽

2017 ◽

Vol 90 (10) ◽

pp. 864-866

Author(s):

Daniel Toboła ◽

Jolanta Cyboroń ◽

Aneta Łętocha

Keyword(s):

Heat Treatment ◽

Residual Stress ◽

Wear Resistance ◽

Surface Layer ◽

Tool Steel ◽

Hard Turning ◽

Geometrical Structures ◽

Gas Quenching ◽

Vacuum Furnaces ◽

Steel Heat

Two mechanical processes of surface layer (SL) modification were performed on Vanadis 8 tool steel: grinding (G) and hard turning (HT). This steel is classified as powder metallurgy (P/M) high-alloyed tool steel. Heat treatment was carried out in vacuum furnaces with gas quenching until hardness of 64 ±1 HRC was achieved. Surface geometrical structures (SGS), microstructures, residual stress levels and wear resistance of SL resulting in these processes were compared.

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Thick Si-doped DLC coatings with high load bearing capacity on cold working tool steels by PECVD

Journal of Tribology ◽

10.1115/1.4053191 ◽

2021 ◽

pp. 1-19

Author(s):

Xinyu Wang ◽

Xudong Sui ◽

Shuaituo Zhang ◽

Mingming Yan ◽

Yan Lu ◽

...

Keyword(s):

Wear Resistance ◽

Cold Working ◽

Chemical Vapor ◽

Tool Steels ◽

Dlc Coatings ◽

Wear Rates ◽

Si Doped ◽

Silicon Doped ◽

Hydrogenated Amorphous ◽

Degree Of Graphitization

Abstract For improving the wear resistance, thick silicon doped hydrogenated amorphous carbon (a-SiC:H) coatings were deposited on cold working tool steels by Plasma Enhanced Chemical Vapor Deposition (PECVD) technology. The increase of the acetylene (C2H2) flow rate distinctly tuned the microstructure of a-SiC:H coatings, including an increase in the coating thickness (>15 μm), a decrease in the silicon content, a greater sp2/sp3 ratio and higher degree of graphitization. The highest hardness of 19.61 GPa and the greatest critical load of 50.7 N were obtained. The coating showed low wear rates against different friction pairs and presented excellent abrasive wear resistance at high applied load and the wear rates decreased with increasing loads, which exhibited an outstanding application prospect in cold working tool steels.

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Phase, microstructure, and wear behavior of Al2O3-reinforced Fe–Si alloy-based metal matrix nanocomposites

Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications ◽

10.1177/1464420719893387 ◽

2019 ◽

Vol 234 (3) ◽

pp. 467-480

Author(s):

Akash Saxena ◽

Neera Singh ◽

Bhupendra Singh ◽

Devendra Kumar ◽

Kishor Kumar Sadasivuni ◽

...

Keyword(s):

Wear Resistance ◽

Metal Matrix ◽

Alloy Composition ◽

Wear Behavior ◽

High Hardness ◽

Industrial Applications ◽

High Wear Resistance ◽

Wear Properties ◽

Metal Matrix Nanocomposites ◽

Matrix Nanocomposites

In the present work, phase, microstructure, and wear properties of Al2O3-reinforced Fe–Si alloy-based metal matrix nanocomposites have been studied. Composites using 2 wt.% and 5 wt.% of Si and rest Fe powder mix were synthesized via powder metallurgy and sintered at different temperature schedules. Iron–silicon alloy specimens were found to have high hardness and high wear resistance in comparison to pure iron specimens. Addition of 5 wt.% and 10 wt.% alumina reinforcement in Fe–Si alloy composition helped in developing iron aluminate (FeAl2O4) phase in composites which further improved the mechanical properties i.e. high hardness and wear resistance. Formation of iron aluminate phase occurs due to reactive sintering between Fe and Al2O3 particles. It is expected that the improved behavior of prepared nanocomposites as compared to conventional metals will be helpful in finding their use for wide industrial applications.

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ELID Grinding Technology of Nano-Ceramic Scalpel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.468-471.1560 ◽

2012 ◽

Vol 468-471 ◽

pp. 1560-1563 ◽

Cited By ~ 1

Author(s):

Ji Cai Kuai ◽

Fei Hu Zhang ◽

Ya Zhong Liu

Keyword(s):

Surface Roughness ◽

Wear Resistance ◽

High Hardness ◽

High Wear Resistance ◽

Preparation Technology ◽

Elid Grinding ◽

High Toughness ◽

Edge Sharpness ◽

Cutting Experiment ◽

Promising Application

As the grain size of nano ceramic has reached nanometer grade, it possesses high hardness, high wear resistance and high toughness. Therefore, the scalpel made by nano ceramic has the virtue of high wear resistance, good corrosion resistance, long service life, non-toxic, non-static, sharp edge and so on, but the processing of this kind of scalpel is extremely difficult. This paper prepares the nano-ceramic scalpel by using ELID grinding technology, and also studies the thickness, surface roughness, edge sharpness of scalpel. The research results show that the thickness of prepared scalpel is 0.3 mm, the surface roughness is 6-60 nm and the edge radius is 200 nm, the cutting experiment on suture shows that this scalpel can meet the requirements of international standard for medical scalpel when the cutting force is less than 0.8 N. This further proves that the ELID grinding technology is suitable for the preparation of nano-ceramic scalpel. The preparation technology and technological equipment of nano-ceramic scalpel are proposed on the basis of above achievements, and this technology possesses promising application prospect.

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Laser alloying of bearing steel with boron and self-lubricating addition

Archives of Mechanical Technology and Materials ◽

10.1515/amtm-2016-0002 ◽

2016 ◽

Vol 36 (1) ◽

pp. 7-11 ◽

Cited By ~ 5

Author(s):

Mateusz Kotkowiak ◽

Adam Piasecki ◽

Michał Kulka

Keyword(s):

Wear Resistance ◽

Calcium Fluoride ◽

High Hardness ◽

Bearing Steel ◽

Operating Conditions ◽

High Wear Resistance ◽

Laser Alloying ◽

Amorphous Boron ◽

Rolling Bearings ◽

Borided Layer

Abstract 100CrMnSi6-4 bearing steel has been widely used for many applications, e.g. rolling bearings which work in difficult operating conditions. Therefore, this steel has to be characterized by special properties such as high wear resistance and high hardness. In this study laser-boriding was applied to improve these properties. Laser alloying was conducted as the two step process with two different types of alloying material: amorphous boron only and amorphous boron with addition of calcium fluoride CaF2. At first, the surface was coated with paste including alloying material. Second step of the process consisted in laser re-melting. The surface of sample, coated with the paste, was irradiated by the laser beam. In this study, TRUMPF TLF 2600 Turbo CO2 laser was used. The microstructure, microhardness and wear resistance of both laser-borided layer and laser-borided layer with the addition of calcium fluoride were investigated. The layer, alloyed with boron and CaF2, was characterized by higher wear resistance than the layer after laser boriding only.

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Enhancing Wear Resistance of Selective Laser Melted Parts: Influence of Energy Density

Journal of Tribology ◽

10.1115/1.4047297 ◽

2020 ◽

Vol 142 (11) ◽

Cited By ~ 2

Author(s):

Y. Yang ◽

Y. Zhu ◽

H. Yang

Keyword(s):

Wear Resistance ◽

Energy Density ◽

Process Parameters ◽

High Hardness ◽

Scanning Speed ◽

Cellular Structures ◽

Wear Rates ◽

Scratch Tests ◽

Hatch Spacing ◽

Metal Additive

Abstract Selective laser melting (SLM) is a rapidly developing metal additive manufacturing technology. SLM process parameters have a direct impact on the microstructure of parts, which further affect wear behaviors. Increasing the wear resistance by tailoring process parameters, instead of postprocessing, is crucial for enhancing surface properties of the SLM-fabricated parts with complicated structures. In this study, 316L stainless steel samples were fabricated using different energy densities by varying hatch spacing and scanning speed. The relative density and hardness were measured, and the microstructures were examined. The wear resistance was evaluated by performing scratch tests. Results show that high hardness was found in the bottom region of the samples by small hatch spacings and the highest hardness of 302.8 ± 4.3 HV was measured in the sample by a hatch spacing of 10 μm. With the increase of energy density from 178 to 533 J/mm3 by reducing hatch spacing, the fraction of cellular structures decreases and columnar structures are more likely to be aligned in a relatively constant tilted angle from the build direction, which significantly improve the ability to resist slipping and deformation, indicated by 90.1%, 45.0%, and 15.7% reductions in wear rates under 1, 3, and 5 N, respectively. With the increase of energy density from 182 to 545 J/mm3 by reducing the scanning speed, the number of cellular structures increases but pores also form, which negatively affects wear resistance.

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Effect of Nickel–Phosphorus and Nickel–Molybdenum Coatings on Electrical Ablation of Small Electromagnetic Rails

Coatings ◽

10.3390/coatings10111082 ◽

2020 ◽

Vol 10 (11) ◽

pp. 1082

Author(s):

Li-Shan Hsu ◽

Pao-Chang Huang ◽

Chih-Cheng Chou ◽

Kung-Hsu Hou ◽

Ming-Der Ger ◽

...

Keyword(s):

Wear Resistance ◽

High Hardness ◽

Electrical Energy ◽

High Wear Resistance ◽

X Ray Diffraction ◽

Molybdenum Coating ◽

Surface Areas ◽

Heat Treated ◽

Electrochemically Deposited ◽

Iron Material

The electromagnetic rail catapult is a device that converts electrical energy into kinetic energy, which means that the strength of electrical energy directly affects the muzzle speed of armature. In addition, the electrical conductivity, electromagnetic rails and armature surface roughness, and the holding force of the rail are influencing factors that cannot be ignored. However, the electric ablation on the surface of the electromagnetic rails caused by high temperatures seriously affects the service life performance of the electromagnetic catapult system. In this study, electrochemically deposited nickel-phosphorus and nickel-molybdenum alloy coatings are plated on the surface of electromagnetic iron rails and their effects on the reduction of ablation are investigated. SEM (scanning electron microscopy) with EDS (energy dispersive spectroscopy) detector, XRD (X-ray diffraction), 3D optical profiler, and Vickers microhardness tester are used. Our results show that the sliding velocity of the armature decreases slightly with the increased roughness of the rail coating surface. On the other hand, the area of electric ablation on the rail surface is inversely related to the hardness of the rail material. The electrically ablated surface areas of the rails are in: annealed nickel–molybdenum < nickel–molybdenum < annealed nickel–phosphorus < nickel–phosphorus < iron material. Heat treatment at 400 and 500 °C, respectively for Ni–P and Ni–Mo alloys, significantly increases hardness due to the precipitation of intermetallic compounds such as Ni3P and Ni4Mo phases. Comprehensive data analysis shows that the annealed nickel–molybdenum coating has the best electrical ablation wear resistance. The possible reason for that might be attributed to the high hardness of the heat-treated nickel–molybdenum coating. In addition, the thermal resistance capability of molybdenum is better than that of phosphorus, which might also contribute to the high wear resistance to electric ablation.

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Comparison of Tribological Performances of High Density Polyethylene Enhanced With Carbon Nanofibers

Volume 2: Biomedical and Biotechnology ◽

10.1115/imece2012-86150 ◽

2012 ◽

Author(s):

Songbo Xu ◽

Aydar Akchurin ◽

X. W. Tangpong ◽

Tian Liu ◽

Weston Wood ◽

...

Keyword(s):

Wear Resistance ◽

High Density Polyethylene ◽

Carbon Nanofiber ◽

Optical Microscope ◽

High Density ◽

High Wear Resistance ◽

Melt Mixing ◽

Wear Rates ◽

Silane Coating ◽

Bearing Materials

High density polyethylene (HDPE) is widely used as bearing material in industrial application because of its low friction and high wear resistance properties. Carbon nanofiber (CNF) reinforced HDPE nanocomposites are promising materials for biomedical applications as well, such as being the bearing materials in total joint replacements. The main objective of the present study is to investigate how the wear of HDPE can be altered by the addition of either pristine or silane treated CNFs at different loading levels (0.5 wt.% and 3 wt.%). Two types of silane coating thicknesses, 2.8 nm and 46 nm, were applied on the surfaces of oxidized CNFs to improve the interfacial bonding strength between the CNFs and the matrix. The CNF/HDPE nanocomposites were prepared through melt mixing and hot-pressing. The coefficients of friction (COFs) and wear rates of the neat HDPE and CNF/HDPE nanocomposites were determined using a pin-on-disc tribometer under dry sliding conditions. The microstructures of the worn surfaces of the nanocomposites were characterized using both scanning electron microscope (SEM) and optical microscope to analyze their wear mechanisms. Compared with the neat HDPE, the COF of the nanocomposites were reduced. The nanocomposite reinforced with CNFs coated with the thicker silane coating (46 nm) at 0.5 wt.% loading level was found to yield the highest wear resistance with a wear rate reduction of nearly 68% compared to the neat HDPE.

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