scholarly journals Effect of the detonation-spraying mode on the tribological properties of NiCr-Al2O3 coatings

2021 ◽  
Vol 5 (1) ◽  
pp. 39-44
Author(s):  
B.K. Rakhadilov ◽  
D.B. Buitkenov ◽  
E. Kabdykenova ◽  
Zh.B. Sagdoldina ◽  
L.G. Zhurerova
Keyword(s):  
Wear Resistance ◽  
Phase Composition ◽  
Tribological Properties ◽  
Volume Fraction ◽  
Oxygen Mixture ◽  
High Wear Resistance ◽  
Wear Volume ◽  
Detonation Spraying ◽  
Filling Volume ◽  
Study Results

The article presents the study results of detonation spraying parameters on the phase composition and tribological properties of NiCr-Al2O3 powder coatings. The spraying was carried out at a ratio of the acetylene-oxygen mixture O2 /C2H2=1.856. The detonation barrel filling volume with an explosive gas mixture varied from 30% to 68%. It is determined that the phase composition of the NiCr-Al2O3 coatings varies depending on the degree of detonation barrel filling. With an increase in the detonation barrel’s filling volume, the intensity of the NiCr diffraction peaks is decreased, and the intensity of the a-Al2O3 reflexes is increased, which indicates an increase in the content of the Al2O3 phase. When low filling volume, there is determined a low coating density and uneven roughness. The tribological test results showed that with an increase in the detonation barrel filling volume, there is a decrease in the wear volume, which confirms the increase in the coatings wear resistance. Determined that the lowest friction coefficient was recorded in the sample obtained at the barrel filling volume 68%. The coatings’ high wear resistance is associated with an increase in the alpha phase volume fraction of a-Al2O3 and coatings density.

scholarly journals Structural Features and Tribological Properties of Detonation Gun Sprayed Ti–Si–C Coating

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 141
Author(s):  
Bauyrzhan Rakhadilov ◽  
Dastan Buitkenov ◽  
Zhuldyz Sagdoldina ◽  
Bekbolat Seitov ◽  
Sherzod Kurbanbekov ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Volume Fraction ◽  
Structural Phase ◽  
Structural Features ◽  
High Wear Resistance ◽  
Technological Parameters ◽  
Detonation Spraying ◽  
Equal Distribution ◽  
Filling Volume ◽  
Detonation Gun

The paper considers the research results of structural-phase state and tribological characteristics of detonation coatings based on Ti–Si–C, obtained at different filling volumes of the explosive gas mixture barrel of a detonation gun. The results analysis indicates that the phase composition and properties of detonation coatings strongly depend on the technological parameters of spraying. With an increase of the explosive mixture in the filling volume of the detonation barrel up to 70% of the coatings consist mainly of the TiC phase, because high temperature leads to a strong decomposition of Ti3SiC2 powders. Thus, the XRD results confirm that at 70% of the explosive gas mixture’s filling volume, partial decomposition and disintegration of the powders occurs after detonation spraying. We established that detonation coatings based on titanium carbosilicide obtained at the explosive gas mixture’s filling volume at 60% are characterized by high wear resistance and adhesive strength. Thermal annealing was performed after spraying in the temperature range of 700–900 °C for 1 h to reduce microstructural defects and improve the Ti–Si–C coating characteristics. As a result of the heat treatment in the Ti–Si–C system at 800 °C, we observed that an increase in the volume fraction of the Ti3SiC2 and TiO2 phases led to a 2-fold increase in microhardness. This means that the after-heat-treatment can provide a sufficient reaction time for the incomplete reaction of the Ti–Si–C (TSC) coating during the detonation gun spraying. Thus, annealing can provide an equal distribution of elements in the coatings.

scholarly journals An Investigation on Tribological Properties and Lubrication Mechanism of Graphite Nanoparticles as Vegetable Based Oil Additive

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yu Su ◽  
Le Gong ◽  
Dandan Chen
Keyword(s):  
Friction Coefficient ◽  
Tribological Properties ◽  
Volume Fraction ◽  
Wear Volume ◽  
Lubrication Mechanism ◽  
Step Method ◽  
Antiwear Properties ◽  
Physical Deposition ◽  
Graphite Nanoparticles ◽  
Friction Reducing

This paper used graphite nanoparticles with the diameter of 35 and 80 nm and LB2000 vegetable based oil to prepare graphite oil-based nanofluids with different volume fractions by two-step method. The tribological properties of graphite nanoparticles as LB2000 vegetable based oil additive were investigated with a pin-on-disk friction and wear tester. Field emission scanning electron microscope (FE-SEM) and energy dispersive spectroscopy (EDS) were used to examine the morphology and the content of some typical elements of wear scar, respectively. Further, the lubrication mechanism of graphite nanoparticles was explored. It was found that graphite nanoparticles as vegetable based oil additive could remarkably improve friction-reducing and antiwear properties of pure oil. With the increase of volume fraction of graphite nanoparticles, the friction coefficient and the wear volume of disk decreased. At the same volume fraction, the smaller particles, the lower friction coefficient and wear volume. The main reason for the improvement in friction-reducing and antiwear properties of vegetable based oil using graphite nanoparticles was that graphite nanoparticles could form a physical deposition film on the friction surfaces.

Experimental investigation of Mechanical and Tribological Properties of Al6061-ZrC-B4C Hybrid Composites

2020 ◽  
Author(s):  
Theerkka tharaisanan Rajamanickam ◽  
Kathiresan Marimuthu
Keyword(s):  
Tensile Strength ◽  
Wear Resistance ◽  
Impact Strength ◽  
Metal Matrix Composites ◽  
Tribological Properties ◽  
Metal Matrix ◽  
Hybrid Composites ◽  
Zirconium Carbide ◽  
High Wear Resistance ◽  
Matrix Composites

Aluminium metal matrix composites (AMMC’s) have been widely used because of their superior properties like high strength to wear ratio, high wear resistance, and higher heat conduction rate. The additions of reinforcements in the form of discontinuous particles lead to an increase in the properties of Metal Matrix Composites (MMC). In this present work, the ALMMC composite was fabricated with the addition of discontinuous reinforcement particles of Zirconium Carbide (ZrC) and Boron Carbide (B4C). The mechanical properties such as tensile strength, hardness, and impact strength were tested as per the ASTM standards. The tribological properties were tested using a pin-on-disc setup under different loading conditions (10, 20, 30, 40 N). Moreover, the morphological characterization of ALMMC was carried out by using the Scanning Electron Microscope (SEM) analysis. Furthermore, the Differential Thermal Analysis (DTA) and Thermogravimetric Analysis (TGA) was accomplished to find the thermal stability of ALMMC. The findings show that the variations of reinforcement of ZrC added had given improved properties like hardness, tensile strength, impact strength and wear resistance.

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.

Effect of carbides on the wear resistance of white cast iron alloyed with 12.7 wt.-% Cr and nickel

2020 ◽  
Vol 62 (8) ◽  
pp. 788-792
Author(s):  
Tanju Teker ◽  
S. Osman Yilmaz ◽  
Tekirdağ Teker
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Cast Iron ◽  
White Cast Iron ◽  
Volume Fraction ◽  
High Wear Resistance ◽  
Homogeneous Distribution ◽  
Nickel Concentration ◽  
Carbide Size ◽  
Wear Tests

Abstract White cast iron with about 12.7 wt.-% chromium was alloyed with Ni, W and Mo for heat treatment applications. Heat treatments were performed at a range of 850-1050 °C for 1 h in order to distribute M7C3 carbides homogeneously in an environment of high wear resistance. The contents of the C, Cr, Ni, Mo, Mn and Si elements selected for the alloys were similar, though a 6 wt.-% nickel concentration was chosen. Microstructural changes in the specimens were examined by scanning electron microscopy (SEM) and optical microscopy (OM). Macro-hardness, average carbide size and volume fraction were analyzed. Wear tests were carried out under different loads of 10, 20 and 30 N. It was seen that heat treatment changed the carbide size and homogeneous distribution of the carbides. Moreover, the addition of nickel to HCrWCI increased fracture toughness and reduced the wear rate.

scholarly journals Structural and Mechanical Properties of a-BCN Films Prepared by an Arc-Sputtering Hybrid Process

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 719
Author(s):  
Yuki Hirata ◽  
Ryotaro Takeuchi ◽  
Hiroyuki Taniguchi ◽  
Masao Kawagoe ◽  
Yoshinao Iwamoto ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Carbon Content ◽  
Photoelectron Spectroscopy ◽  
High Hardness ◽  
Film Structure ◽  
Hybrid Process ◽  
High Wear Resistance ◽  
Wear Volume

Amorphous boron carbon nitride (a-BCN) films exhibit excellent properties such as high hardness and high wear resistance. However, the correlation between the film structure and its mechanical properties is not fully understood. In this study, a-BCN films were prepared by an arc-sputtering hybrid process under various coating conditions, and the correlations between the film’s structure and mechanical properties were clarified. Glow discharge optical emission spectroscopy, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, and Raman spectroscopy were used to analyze the structural properties and chemical composition. Nanoindentation and ball-on-disc tests were performed to evaluate the hardness and to estimate the friction coefficient and wear volume, respectively. The results indicated that the mechanical properties strongly depend on the carbon content in the film; it decreases significantly when the carbon content is <90%. On the other hand, by controlling the contents of boron and nitrogen to a very small amount (up to 2.5 at.%), it is possible to synthesize a film that has nearly the same hardness and friction coefficient as those of an amorphous carbon (a-C) film and better wear resistance than the a-C film.

scholarly journals Effect of physical and chemical factors, arising in elements of implantation systems, on central screws of heads at rehabilitation of patients in orthopedic dentistry clinic

2020 ◽  
Vol 4 (34) ◽  
pp. 35-39
Author(s):  
S. G. Nikitin ◽  
Yu. Yu. Pervov ◽  
R. A. Saleev ◽  
M. A. Amkhadova
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Phase Composition ◽  
Surface Structure ◽  
Functional Properties ◽  
Tribological Properties ◽  
Biological Media ◽  
Relevant Today ◽  
Chemical Factors ◽  
Physical And Chemical

This article is devoted to the question of one of the remote complications in dental implantology — fracture of the central screw of the abutment. Systematic studies of the influence of chemical and phase composition, volume and surface structure of products from titanium-based alloys on the functional properties of the «implant-screw-abutment» system, including corrosion resistance in biological media, have not been carried out. Therefore, the problem of establishing patterns of influence of these factors on the corrosion resistance of the elements of implantation systems, namely the central screw, and the study of its tribological properties (wear resistance), are relevant today.

Microstructure and Tribological Properties of Stellite21 Coating by Electro-Spark Deposition

2013 ◽  
Vol 423-426 ◽  
pp. 939-943 ◽  
Author(s):  
Qi Feng Jing ◽  
Ye Fa Tan ◽  
Hui Yong Ji ◽  
Xiao Long Wang ◽  
Li Gao ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Phase Composition ◽  
Abrasive Wear ◽  
Tribological Properties ◽  
Wear Mechanism ◽  
Alloy Coating ◽  
Fatigue Wear ◽  
Compact Structure

Setellite21 cobalt-based alloy coating was deposited on 45 steel by electro-spark deposition. Microstructure and phase composition of the coating were analyzed. Wear resistance and wear mechanism of the coating were researched. The results indicate that the coating with compact structure is mainly composed of Co, Co6W6C, CoCx and CoCr. Average microhardness of the coating is 445.34 HV0.5, which is about 2 times to that of the substrate. The coating presents excellent wear resistance with no obvious peelings and scratches. Wear resistance of the coating is about 2.3~2.7 times to that of the substrate. Wear mechanism of the coating mainly contains abrasive wear and fatigue wear, and along with oxidization wear.

Effects of titania on tribological and thermal properties of polymer/graphene nanocomposites

2019 ◽  
Vol 33 (8) ◽  
pp. 1030-1047 ◽  
Author(s):  
UO Uyor ◽  
API Popoola ◽  
OM Popoola ◽  
VS Aigbodion
Keyword(s):  
Thermal Stability ◽  
Wear Resistance ◽  
Vinylidene Fluoride ◽  
Polymeric Materials ◽  
Solid Lubrication ◽  
High Wear Resistance ◽  
Wear Volume ◽  
Graphene Nanocomposites ◽  
Solution Blending ◽  
Pure Pvdf

In most engineering applications where fluid lubrication is practically impossible such as high temperature environment, solid lubrication becomes an alternative option. Polymers such as polytetrafluoroethylene are often used for solid lubrication due to their ability to provide low friction on interfacial sliding conditions. However, polymeric materials often show low wear resistance, which limits their applications. Therefore, there is need for high wear resistance polymers or polymer composites for such application. In this study, wear resistance of poly (vinylidene fluoride) (PVDF) was improved by incorporating hydroxylated titanium dioxide (TD-OH) and functionalized graphene nanoplatelets (fGNPs). The composites were fabricated by solution blending and further processed by melt compounding. Raman and X-ray diffractometer were used to characterize the particles, while morphological study and wear scars on the composite samples were examined using scanning electron microscope. From the results obtained, wear volume (WV) reduced from about 0.6255 mm3 for pure PVDF to 0.2439 mm3 for 3.34 wt% fGNPs composite and further reduced to 0.1473 mm3 with the addition of 10 wt% TD-OH to 3.34 wt% fGNPs composite. These are about 61% and 76% reduction respectively, compared to pure PVDF. It was noted that increase in TD-OH content up to 20 wt% in fGNPs binary composites increased the WV of the ternary composites. This indicates that ceramic nano-fillers at appropriate proportions in polymer/graphene composites can enhance the wear resistance of such composites. On the other hand, the ternary composites showed lower thermal stability compared to the binary composites, which was attributed to low thermal stability product(s) of chemical reaction between fGNPs and TD-OH in the PVDF matrix.

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