scholarly journals Effect of High−Speed Powder Feeding on Microstructure and Tribological Properties of Fe−Based Coatings by Laser Cladding

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1456
Author(s):  
Qiang Wang ◽  
Runling Qian ◽  
Ju Yang ◽  
Wenjuan Niu ◽  
Liucheng Zhou ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Laser Cladding ◽  
Tribological Properties ◽  
Wear Mechanism ◽  
High Speed ◽  
High Efficiency ◽  
Adhesive Wear ◽  
Steel Substrate ◽  
Powder Materials ◽  
Powder Feeding

In order to improve the wear resistance of 27SiMn steel substrate, Fe−based alloy coatings were prepared by laser cladding technology in the present study. In comparison to the conventional gravity powder feeding (GF) process, high−speed powder feeding (HF) process was used to prepare Fe−based alloy coating on 27SiMn steel substrate. The effect of diversified energy composition of powder materials on the microstructure and properties of coatings were systematically studied. X−ray diffractometer (XRD), optical microscope (OM) and scanning electron microscope (SEM) were used to analyze the phase structure and microstructure of Fe−based alloy coatings, and the hardness and tribological properties were measured by the microhardness tester and ball on disc wear tester, respectively. The results show that the microstructure of conventional gravity feeding (GF) coatings was composed of coarse columnar crystals. In comparison, owing to the diversification of energy composition, the microstructure of the high−speed powder feeding (HF) coatings consists of uniform and small grains. The total energy of the HF process was 75.5% of that of the GF process, proving that high−efficiency cladding can be achieved at lower laser energy. The refinement of the microstructure is beneficial to improve the hardness and wear resistance of the coating, and the hardness of the HF coating increased by 9.4% and the wear loss decreased to 80.5%, compared with the GF coating. The wear surface of the HF coating suffered less damage, and the wear mechanism was slightly adhesive wear. In contrast, wear was more serious in the GF coating, and the wear mechanism was transformed into severe adhesive wear.

scholarly journals Enhanced Tribological Properties of LA43M Magnesium Alloy by Ni60 Coating via Ultra-High-Speed Laser Cladding

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 638 ◽  
Author(s):  
Osama Asghar ◽  
Lou Li-Yan ◽  
Muhammad Yasir ◽  
Li Chang-Jiu ◽  
Li Cheng-Xin
Keyword(s):  
Wear Resistance ◽  
Magnesium Alloy ◽  
Laser Cladding ◽  
Wear Mechanism ◽  
High Speed ◽  
Surface Engineering ◽  
Energy Dispersive Spectrometer ◽  
Wear Loss ◽  
Cross Sectional ◽  
Ultra High Speed

Laser modification techniques have been widely adopted in the field of surface engineering. Among these modified techniques, ultra-high-speed laser cladding is trending most nowadays to fabricate wear-resistant surfaces. The main purpose of this research is to provide a detailed insight of ultra-high-speed laser cladding of hard Ni60 alloy on LA43M magnesium alloy to enhance its surface mechanical properties. Multiple processing parameters were investigated to obtain the optimal result. The synthesized coating was studied microstructurally by field emission scanning electron microscopy (FESEM) equipped with an energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). The microhardness and wear resistance of the Ni60 coating were analyzed under Vickers hardness and pin on disc tribometer respectively. The obtained results show that the dense Ni60 coating was fabricated with a thickness of 300 μm. No cracks and porosities were detected in cross-sectional morphology. The Ni60 coating was mainly composed of γ-Ni and hard phases (chromium carbides and borides). The average microhardness of coating was recorded as 948 HV0.3, which is approximately eight times higher than that of the substrate. Meanwhile, the Ni60 coating exhibited better wear resistance than the substrate, which was validated upon the wear loss and wear mechanism. The wear loss recorded for the substrate was 6.5 times higher than that of the coating. The main wear mechanism in the Ni60 coating was adhesive while the substrate showed abrasive characteristics.

Influence Nitriding in the Electrolytic Plasma on the Tribological Properties of Low-Alloy 40Cr Steel

2013 ◽  
Vol 785-786 ◽  
pp. 848-851
Author(s):  
Mazhyn Skakov ◽  
Yerzhan Sapatayev ◽  
Michael Scheffler
Keyword(s):  
Wear Resistance ◽  
Tribological Properties ◽  
Wear Mechanism ◽  
Adhesive Wear ◽  
Plasma Nitriding ◽  
40Cr Steel

This paper presents the results of research influence nitriding in electrolytic plasma on the tribological properties of low-alloy 40Cr steel. It is shown that the process of electrolytic plasma nitriding can significantly increase the wear resistance of the samples 40Cr steel. Found that after nitriding component adhesive wear mechanism is changed to abrasion.

scholarly journals Wear Properties of TiC-Reinforced Co50 Composite Coatings from Room Temperature to High Temperature

2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Nga Thi-Hong Pham ◽  
Van-Thuc Nguyen
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Laser Cladding ◽  
Wear Mechanism ◽  
Room Temperature ◽  
Steel Substrate ◽  
Composite Coatings ◽  
H13 Steel ◽  
Fatigue Wear ◽  
Wear Rates

In this paper, the laser cladding is created by using Co50 powder and TiC mixture, covering a H13 hot-working steel substrate. The samples are analyzed by the hardness test, XRD, SEM, and friction test to identify the forming phases, microhardness distribution, and wear-resistant characteristics. The results indicated that hardness reduces from the coating zone to the substrate, achieving the highest value at the coating zone. Increasing the content of TiC results in improving the coating hardness. The coatings with 10%–20% TiC show high-quality surface morphology and macrograph. With 30% TiC, the hardness obtains a higher hardness, but the surface appears to crack. The microstructures of the coatings present a well-mixed and well-distribution of the TiC particle on the Co matrix. The friction coefficient of H13 steel and Co50 coating reaches the maximum value when the load is 50 N and mostly decreases with the increase in the load. The wear rates of H13 steel and Co50 coatings mainly increase with the increase in the load. The temperature has a greater influence on the friction coefficient of the Co50 coating. However, the temperature has a small effect on the friction coefficient of the 20% TiC coating. The wear resistance of 20% TiC coating is higher than that of H13 steel, Co50 coating, and 10% TiC composite coating. At room temperature, the wear mechanism of the coating is mainly brittle spalling, adhesive wear, and ploughing. At 700°C, the wear mechanism is mostly oxidation wear and fatigue wear. After laser cladding, the service life of the coated surface could be greatly improved. The Co + 20% TiC coating has high hardness and wear resistance.

Fabrication of SiC Particulates Reinforced MoSi2 Composite Coating by Laser Cladding

2008 ◽  
Vol 373-374 ◽  
pp. 304-307
Author(s):  
Sen Yang ◽  
Ming Run Wang ◽  
Tao Gong ◽  
Wen Jin Liu
Keyword(s):  
Wear Resistance ◽  
Laser Cladding ◽  
Continuous Wave ◽  
Steel Substrate ◽  
Laser Output Power ◽  
Scanning Velocity ◽  
Sic Particulates ◽  
Metallurgical Bond ◽  
Improve Wear Resistance

In order to improve wear resistance of carbon steel, laser cladding experiments were carried out using a 3kW continuous wave CO2 laser. The diameter of the laser beam was 3-5mm, the scanning velocity was 3-10mm/s, and the laser output power was 1.0-1.3kW. The experimental results showed that MoSi2/SiCP composites coating could be in-situ synthesized from mixture powders of molybdenum, silicon and SiC by laser cladding. A good metallurgical bond between the coating and the substrate could be achieved. The microstructures of the coating were mainly composed of MoSi2, SiC and FeSiMo phases. The average microhardness of the coating was about HV0.21300, about 6.0 times larger than that of steel substrate.

Wear Resistance of Laser Cladded NiCrFeSiB Self-Fluxing Composite Coatings

2016 ◽  
Vol 254 ◽  
pp. 290-295
Author(s):  
Iosif Hulka ◽  
Ion Dragoş Uţu ◽  
Viorel Aurel Şerban ◽  
Alexandru Pascu ◽  
Ionut Claudiu Roată
Keyword(s):  
Wear Resistance ◽  
Laser Cladding ◽  
Wear Behavior ◽  
Protective Coatings ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Base Material ◽  
Laser Cladding Process ◽  
Metallurgical Bond ◽  
Feedstock Material

Laser cladding process is used to obtain protective coatings using as heat source a laser. This melts the substrate and the feedstock material to create a protective coating and provides a strong metallurgical bond with minimal dilution of the base material and reduced heat affected zone. In the present study a commercial NiCrSiFeB composition was deposited by laser cladding process using different parameters onto the surface of a steel substrate. The obtained coatings were investigated in terms of microstructure, hardness and wear behavior. The experimental results revealed that the laser power had a considerable influence on the wear resistance of NiCrSiFeB coatings.

Effects of Electrolyte Plasma Carbonitriding on Tribological Properties of High Speed Steel

2013 ◽  
Vol 712-715 ◽  
pp. 7-11 ◽  
Author(s):  
Mazhyn Skakov ◽  
Bauyrzhan Rakhadilov ◽  
Michael Sсheffler
Keyword(s):  
Wear Resistance ◽  
Tribological Properties ◽  
High Speed ◽  
High Speed Steel ◽  
Scratch Test ◽  
Abrasive Wear Resistance ◽  
R6m5 Steel ◽  
Surface Layers ◽  
Test Conditions ◽  
Modified Layer

This paper presents research of influence electrolyte plasma carbonitriding on tribological properties of R6M5 high-speed steel. Shows perspectiveness of carbonitriding high-speed steels in electrolyte plasma. The results of research demonstrated increasing wear-resistance of R6M5 steel after carbonitriding in electrolyte plasma. Under the same test conditions by the method of scratch-test have been determined that the depth of the scar of a modified layer has become less in comparison with the original sample, which indicates a significant increase of wear-resistance and hardness of the surface carbonitriding layer R6М5 steel. It was set that after electrolytic-plasma carbonitriding abrasive wear-resistance of the surface layers of R6M5 steel is increased by 25%. Introduction

The Research of Thermal Arc Sprayed Coatings Tribological Properties by Using Rubber Wheel Test

2015 ◽  
Vol 220-221 ◽  
pp. 693-697 ◽  
Author(s):  
Justinas Gargasas ◽  
Algirdas Vaclovas Valiulis ◽  
Irmantas Gedzevicius ◽  
Hanna Pokhmurska
Keyword(s):  
Wear Resistance ◽  
Mass Loss ◽  
Tribological Properties ◽  
Steel Substrate ◽  
High Wear Resistance ◽  
Tribological Behaviour ◽  
Oxide Inclusions ◽  
Porosity Of Coatings ◽  
Sprayed Coatings ◽  
Thermal Sprayed Coatings

This paper present the result obtained from new experimental STEIN-MESYFIL 953 V; STEIN-MESYFIL 954 V coatings. The surfacing material was wires of 1.6 mm diameter. The tests aimed at determining wear resistance of coatings sprayed on steel substrate. The investigation shows that the tribological behaviour of new experimental thermal arc sprayed coatings is greatly affected by its microstructural constituents such as porosity, oxide inclusions, and microhardness of coatings. Results show that increasing porosity of coatings twice, it doubles the mass loss. Results for thermal sprayed coatings of all experiments showed their high wear resistance and are discussed.

Influence of thermal cycling modes on VK8 hard alloy mechanical and tribological properties

2020 ◽  
pp. 55-65
Author(s):  
S. I. Bogodukhov ◽  
E. S. Kozik ◽  
E. V. Svidenko
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Wear Resistance ◽  
Thermal Cycling ◽  
Hard Alloy ◽  
Tribological Properties ◽  
High Speed ◽  
Metal Cutting ◽  
Hard Alloys ◽  
Mechanical And Tribological Properties

Hard alloys are popular materials widely used in the toolmaking industry. Refractory carbides included in their composition make carbide tools very hard (80 to 92 HRA) and heat-resistant (800 to 1000 °С) so as they can be used at cutting speeds several times higher than those used for high-speed steels. However, hard alloys differ from the latter by lower strength (1000 to 1500 MPa) and the absence of impact strength, and this constitutes an urgent problem. We studied the influence of thermal cycling modes on the mechanical and tribological properties of VK8 (WC–8Co) hard alloy used in the manufacture of cutters and cutting inserts for metal working on metal-cutting machines. As the object of study, we selected 5×5×35 mm billets made of VK8 (WC–8Co) alloy manufactured by powder metallurgy methods at Dimitrovgrad Tool Plant. The following criteria were selected for heat treatment mode evaluation: Vickers hardness, flexural strength, and mass wear resistance (as compared to the wear of asreceived samples that were not heat treated). Plates in the initial state and after heat treatment were subjected to abrasion tests. Wear results were evaluated by the change in the mass of plates. Regularities of the influence of various time and temperature conditions of heat treatment on the tribological properties of products made of VK group tungsten hard alloys were determined. An increase in the number of thermal cycling cycles improved such mechanical properties of the VK8 hard alloy as strength and hardness. When repeating the cycles five times, an increase in abrasive wear resistance was obtained compared to the initial nonheat-treated sample. The elemental composition of the VK8 hard alloy changed insignificantly after thermal cycling, only a slight increase in oxygen was observed on the surface of plates. The grain size after thermal cycling increased in comparison with the initial VK8 hard alloy. It was found that VK8 hard alloy thermocyclic treatment leads to a change in the phase composition. X-ray phase analysis showed the presence of a large amount of α-Co with an hcp-type lattice on the surface of a hard alloy and a solid solution of WC in α-Co. A change in the cobalt modification ratio causes a decrease in microstresses. An analysis of the carbide phase structure state showed that the size of crystallites and microstresses changed after thermal cycling. The lattice constant of the cobalt cubic solid solution decreased, which may indicate a decrease in the amount of tungsten carbide and carbon dissolved in it. Statistical processing of experimental results included the calculation of the average value of the mechanical property, its dispersion and standard deviation in the selected confidence interval.

Process Optimization and Properties of Laser Cladding High Vanadium High Speed Steel Coatings on Nodular Cast Iron

2013 ◽  
Vol 712-715 ◽  
pp. 611-614 ◽  
Author(s):  
Ni Jun Xu ◽  
Jian Bin Lv ◽  
Ting Sun ◽  
Chang Sheng Liu
Keyword(s):  
Wear Resistance ◽  
Cast Iron ◽  
Laser Cladding ◽  
High Speed ◽  
High Speed Steel ◽  
Nodular Cast Iron ◽  
Vanadium Content ◽  
Treatment Technology ◽  
Metallurgical Bonding ◽  
Steel Rolls

As withstanding very high loads, thermal cycling leading to thermal fatigue, and severe environmental in the steel industry, rolls with long service life are specially required. High speed steel with high vanadium content is a newly-developed wear-resistance material that has been studied and used in some countries for making steel rolls. As a surface treatment technology, laser cladding can fabricate coating to improve the wear resistance of substrate. In this paper, the substrates for laser cladding were nodular cast iron rolls, Nd: YAG solid pulsed laser was used to explore the feasibility of preparation high vanadium high speed steel (HVHSS) coatings. The Nd: YAG laser cladding results that the coated layers combined metallurgically with the substrate with a lot of microcracks. The average microhardness up to 650 HV is more than 2 times as high as that of the substrate. After laser remelting, a fully dense and crack free HVHHS coating with an excellent metallurgical bonding was deposited. The presence of VC in the coating mainly improves the microhardness of coating up to about 650 HV.

Sign in / Sign up

Export Citation Format

Share Document