scholarly journals INVESTIGATION OF CHARACTERISTICS OF SPRAYED NI-CR AND NI-CR-WC COATINGS / PURKŠTINIŲ NI-CR IR NI-CR-WC DANGŲ SAVYBIŲ TYRIMAS

2017 ◽  
Vol 8 (6) ◽  
pp. 615-620
Author(s):  
Ovidijus Jarašūnas ◽  
Olegas Černašėjus
Keyword(s):  
Wear Resistance ◽  
Elastic Modulus ◽  
Chemical Composition ◽  
Tribological Properties ◽  
Substrate Heating ◽  
Steel Substrates ◽  
Sprayed Coatings

The article deals with the flame sprayed Ni-Cr and Ni-Cr-WC coatings on construction S235 steel substrates. Before spraying, the surfaces of substrates were treated mechanically. Using the different chemical composition of Ni-Cr and Ni-Cr-WC spraying powder and additional substrate heating till 250–290 °C, were sprayed coatings. The microstructure, porosity, hardness, elastic modulus, wear resistance of the Ni-Cr and Ni-Cr-WC coatings were investigated in the work. The influence of the chemical composition and WC content of the coatings on the various physical and tribological properties of the coatings were evaluated. Also the dependence of these coatings characteristics was investigated. Straipsnyje nagrinėjamos liepsninio purškimo būdu ant konstrukcinio S235 plieno substrato užpurkštos Ni-Cr dangos. Substrato paviršiai prieš purškiant buvo apdoroti mechaniniu būdu. Naudojant skirtingos cheminės sudėties Ni-Cr ir Ni-Cr-WC purškimo miltelius ir papildomai pakaitinus substratą iki 250–290 °C temperatūros, buvo užpurkštos dangos. Darbe ištirta gautų Ni-Cr ir Ni-Cr-WC dangų mikrostruktūra, akytumas, kietumas, tamprumo modulis ir atsparumas dilimui. Įvertinta dangų cheminės sudėties ir WC karbidų įtaka įvairioms dangų fizikinėms, tribologinėms savybėms, nustatytos šių dangų charakteristikų priklausomybės.

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.

Effect of Atomic Oxygen Irradiation on the Structural and Tribological Properties of the MoS2/Al2O3/PI Composites

2016 ◽  
Vol 674 ◽  
pp. 239-243
Author(s):  
Gai Zhao ◽  
Qi Hua Wang ◽  
Irina Hussainova ◽  
Qing Jun Ding
Keyword(s):  
Wear Resistance ◽  
Chemical Composition ◽  
Tribological Properties ◽  
Photoelectron Spectroscopy ◽  
Atomic Oxygen ◽  
Wear Behavior ◽  
Low Earth Orbit ◽  
High Wear Resistance ◽  
Composite Surface ◽  
Good Thermal Stability

Polyimide (PI) composites have been widely used in a space science due to extraordinary properties, such as excellent mechanical and electrical properties, good thermal stability and chemical inertness, as well as high wear resistance. However, atomic oxygen (AO), as one of the main radiated constituents in low earth orbit, had an important influence on the structrural and tribological properties of the polyimide matrix. To investigate the mechanism of AO erosion on polyimide, MoS2/Al2O3/PI composites were fabricated by means of a hot-press molding technique and irradiated by AO in a ground-based simulation system. The chemical composition change of the irradiated surface was examined by X-ray photoelectron spectroscopy (XPS). Then, the friction and sliding wear behavior against GCr15 steel balls were evaluated in a ground-based simulation facility using ball-on-disk tribology test rig. The worn morphologies and radiated surfaces of the materials were observed by Scanning electron microscope (SEM) to reveal the wear mechanism. Experimental analysis indicated that oxidation induced by AO irradiation and degradation of PI molecular chains on the composite’ surface results in change in chemical composition and formation of “carpet-like” structures. Affected layer, gradually formed during the process of irradiation, plays an important role for wear performance of the materials increasing friction coefficient and wear rate. Incorporation of Al2O3 nanofibers and MoS2 nanoparticles is shown to be favourable for AO resistance, which is helpful for improvement in wear resistance of the PI.

Assessment of Tribological Properties of Low Friction Thin Layers Produced by Vacuum Methods

2019 ◽  
Vol 293 ◽  
pp. 125-140
Author(s):  
Agnieszka Paradecka ◽  
Krzysztof Lukaszkowicz ◽  
Jozef Sondor
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Chemical Analysis ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Structural Changes ◽  
Thin Layers ◽  
Low Friction ◽  
Topographic Analysis ◽  
Steel Substrates

Low friction thin layers are an excellent alternative for conventional coatings. They provide increased life of the elements, to which they were applied, due to enhancing the hardness or chemical and electrochemical resistance. They help to avoid the cracks, oxidation, as well as possible structural changes during the element's work. However, they primarily improve tribological properties by increasing wear resistance and reducing the friction. This also applies to components operating under variable conditions such as load, speed, temperature. The presented article analyzes the properties of various low-friction thin layers deposited by vacuum methods on the steel substrates. DLC, TiC, MoS2, CrCN thin layers were chosen, as they achieve the lowest possible coefficient of friction. In the framework of this work the measurements of adhesion of the investigated layers to the substrate as well as the friction coefficient, chemical analysis, microstructure and topographic analysis of the low-friction layers were carried out.

Tribological properties and microstructures of Al2O3-TiC-TiB2 reinforced composites

2017 ◽  
Vol 24 (5) ◽  
pp. 715-720
Author(s):  
Peng Li
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Elastic Modulus ◽  
Dilution Rate ◽  
Tribological Properties ◽  
Molten Pool ◽  
Aviation Material ◽  
Reinforced Composites ◽  
Stabilized Zirconia ◽  
Yttria Partially Stabilized Zirconia

AbstractTi-3Al-2V alloy is an important aviation material but shows poor resistance to slid wear. Laser cladding of the Fe3Al-B4C pre-placed powders on a Ti-3Al-2V substrate can form the TiC-TiB2 reinforced composites, which improved the wear resistance of the substrate. In this study, it was noted that the addition of the Al2O3 and 7 wt.% yttria partially stabilized zirconia (YPSZ) was able to further increase the wear resistance of such composites. Al2O3 increased the dilution rate of the substrate to the laser molten pool to a certain extent; moreover, Al2O3 improved the hardness, elastic modulus and the mechanical properties of such laser clad composites. The YPSZ addition led t-ZrO2-ZrSiO4 to be produced in such composites.

scholarly journals Tribological behavior of low-alloyed steel after nitriding

2020 ◽  
Vol 26 (3) ◽  
pp. 78-83
Author(s):  
Martin Vicen ◽  
Otakar Bokůvka ◽  
Ružica Nikolić ◽  
Jozef Bronček
Keyword(s):  
Wear Resistance ◽  
Chemical Composition ◽  
Tribological Properties ◽  
Tribological Behavior ◽  
Nitride Layer ◽  
Substrate Material ◽  
Alloyed Steel ◽  
Nano Indentation ◽  
Indentation Tests ◽  
Low Alloyed Steel

AbstractThe tribological properties of the nitride layer applied to the low-alloyed steel were investigated in this research. Experimental work included determination if the chemical composition, wear resistance, Rockwell, Vickers and nano-indentation tests, both of the substrate material – the low-alloyed steel and the deposited nitride layer. From the results obtained in those experiments authors concluded that applying the nitride layer does not significantly improve the tribological properties of the tested lowalloyed steel samples, thus this process is not recommended for achieving that purpose.

scholarly journals Effect of Negative Bias Voltage on Tribological Properties under High Relative Humidity Environment and Corrosion Resistance of Boron Carbide Coatings

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1518
Author(s):  
Ping Zhong ◽  
Xueqian Cao ◽  
Lunlin Shang
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Elastic Modulus ◽  
Relative Humidity ◽  
Bias Voltage ◽  
Tribological Properties ◽  
Negative Bias ◽  
Negative Bias Voltage ◽  
Excellent Corrosion Resistance ◽  
Humidity Environment

Humid air is a very important service environment, in which metal friction parts should be enhanced to offer excellent corrosion resistance and wear resistance. The B4C coating is an excellent candidate material to enhance the corrosion resistance and tribological behaviors. The purpose is to investigate the effect of negative bias voltages on the tribological properties of B4C coatings under a high relative humidity environment. Amorphous B4C coatings were successfully prepared by closed field unbalanced magnetron sputtering technology and its microstructure, hardness, elastic modulus, adhesive force and tribological properties were systematically studied. Results demonstrate that the B4C coatings deposited at each negative bias voltage have a columnar structure and the surface roughness remained unchanged (about 1.0 nm), while the thickness, hardness, elastic modulus and adhesion force increase first and then decrease with the negative bias voltage increasing. Among them, the B4C (−50 V) coating showed the best mechanical properties. It should be noted that the B4C (−50 V) coating with an excellent corrosion resistance also exhibits the lowest friction coefficient (~0.15) and wear resistance (7.2 × 10−7 mm3·N−1·m−1) under humid air (85% RH). This is mainly due to the tribochemical reaction of B4C during a sliding process to produce boric acid at the sliding interface. B4C coatings can provide an excellent corrosion resistance and high wear resistance due to their high chemical stability and high hardness.

Study on the Tribological Properties of Low-Power Plasma-Sprayed Al-Cu-Cr Quasicrystalline Coating

2009 ◽  
Vol 610-613 ◽  
pp. 641-646 ◽  
Author(s):  
Ying Qing Fu ◽  
Feng Zhou ◽  
De Ming Yang ◽  
Nan Xiang Li ◽  
Yang Gao
Keyword(s):  
Wear Resistance ◽  
Low Power ◽  
Tribological Properties ◽  
Volume Fraction ◽  
Steel Substrate ◽  
Wear Test ◽  
Quasicrystalline Phase ◽  
Dry Sliding Wear ◽  
1045 Steel ◽  
Sprayed Coatings

Al-Cu-Cr quasicrystalline coatings were prepared by low power plasma spraying with axially-fed powder systerm. The Al65Cu20Cr15 powders were deposited on AISI 1045 steel substrate at the power ranged from 4.0 to 5.5 kW. The effects of H2/Ar flow ratio on the phase composition, microstructure and tribological properties of the as-sprayed coatings were investigated. The XRD results showed that the feedstock powders and as-sprayed coatings contained a predominant icosahedral quasicrystalline phase I-Al65Cu24Cr11 and three minor crystalline phases, including a body-centered cubic α-Al69Cu18Cr13, a monoclinic θ-Al13Cr2 (i.e. Al83Cu4Cr13) and a hexagonal ε-Al2Cu3. A qualitative analysis on the XRD patterns indicated that the volume fraction of any crystalline phase (α, ε or θ) in the coatings increased, while the quasicrystalline I-phase decreased with the rise of hydrogen (H2) content in the working gas. However, as increasing the plasma power, the friction and wear resistance of the coating were improved under the same dry sliding wear test conditions. The improvementincrease of the wear resistance may be attributed to the high hardness of quasicrystal.

scholarly journals The Effect of Polytetrafluoroethylene (PTFE) Particles on Microstructural and Tribological Properties of Electroless Ni-P+PTFE Duplex Coatings Developed for Geothermal Applications

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 670
Author(s):  
Gifty Oppong Boakye ◽  
Arna María Ormsdóttir ◽  
Baldur Geir Gunnarsson ◽  
Sandeep Irukuvarghula ◽  
Raja Khan ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Tribological Properties ◽  
Complex Geometry ◽  
Corrosion And Wear ◽  
Functional Layer ◽  
Scaling Properties ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
Duplex Coating ◽  
Wear Protection

The selection of electroless nickel-phosphorus plating (ENP) has been inclined towards their properties and advantages with complex geometry applications. These properties include coating uniformity, low surface roughness, low wettability, high hardness, lubricity, and corrosion- and wear-resistance. Materials used in geothermal environments are exposed to harsh conditions such as high loads, temperature, and corrosive fluids, causing corrosion, scaling, erosion and wear of components. To improve the corrosion- and wear-resistance and anti-scaling properties of materials for geothermal environment, a ENP duplex coating with PTFE nanoparticles was developed and deposited on mild steel within the H2020 EU Geo-Coat project. ENP thin adhesive layer and ENP+PTFE top functional layer form the duplex structure of the coating. The objective of this study was to test the mechanical and tribological properties of the developed ENP-PTFE coatings with varying PTFE content. The microstructural, mechanical and tribological properties of the as-deposited coating with increasing PTFE content in the top functional layer in the order: ENP1, ENP2 and ENP3 were evaluated. The results showed maximum wear protection of the substrates at the lowest load; however, increasing load and sliding cycles increased the wear rates, and 79% increased lubrication was recorded for the ENP2 duplex coating. The wear performance of ENP3 greatly improved with a wear resistance of 8.3 × 104 m/mm3 compared to 6.9 × 104 m/mm3 for ENP2 and 2.1 × 104 m/mm3 for ENP1. The results are applicable in developing low friction, hydrophobic or wear-resistive surfaces for geothermal application.

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