scholarly journals Effect of TiB2 Content on Properties of Nickel-Coated Graphite Self-Lubricating Coating Prepared by Laser Cladding

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1501
Author(s):  
Shanshan Liu ◽  
Ming Pang
Keyword(s):  
Laser Cladding ◽  
Composite Coatings ◽  
Friction Reduction ◽  
Wear Volume ◽  
Wear Loss ◽  
Wear Properties ◽  
Hardness Tester ◽  
Graphite Morphology ◽  
Energy Spectrometer ◽  
Tib2 Coating

To improve the anti-wear and friction-reducing properties of self-lubricating coatings, Ni60/Nickel-coated graphite/TiB2 composite coatings with different contents were prepared by laser cladding. The coating properties were characterized by X-ray diffractometer (XRD), scanning electron microscope (SEM), energy spectrometer (EDS), electrochemical workstation, micro-Vickers hardness tester, and friction and wear tester. The results showed that with the increase in TiB2 content, the graphite morphology changed from spherical at 0 wt.% TiB2 content to a little black graphite alone at 14 wt.% TiB2 to irregular agglomerates at 22 wt.% TiB2. Furthermore, the hardness of the coatings increased with increasing TiB2 content, and the 63% Ni60 + 15% nickel-coated graphite + 22% TiB2 coating had the highest hardness. TiC and Cr7C3 were generated in the coatings with the addition of nickel-coated graphite, creating a dispersion reinforcement effect, so that the hardness of these coatings was higher than that of the 86% Ni60 + 0% nickel-coated graphite + 14% TiB2 coating without the addition of nickel-coated graphite. In addition, the 71% Ni60 + 15% Ni-coated graphite + 14% TiB2 coating had the lowest friction coefficient, wear loss, and wear volume, thus exhibiting excellent friction reduction and anti-wear properties. The 71% Ni60 + 15% nickel-coated graphite + 14% TiB2 coating had excellent corrosion resistance.

scholarly journals Laser Cladding of Ni-Co-W Composite Coating on Stainless Steel to Enhance Wear Resistance

2021 ◽  
Author(s):  
Linlin ZHANG ◽  
Dawei ZHANG
Keyword(s):  
Stainless Steel ◽  
Wear Resistance ◽  
Composite Coating ◽  
Laser Cladding ◽  
Composite Coatings ◽  
Eutectic Structure ◽  
Wear Properties ◽  
Fine Grained ◽  
Noticeable Improvement ◽  
Enhance Wear Resistance

Ni-Co-W composite coatings modified by different contents of Co-based alloy powder in the Ni-based alloy with 35 wt.% WC (Ni35WC) were deposited on stainless steel by laser cladding. The influence of compositional and microstructural modification on the wear properties has been comparatively investigated by XRD, SEM, and EDS techniques. It was found that the austenite dendrites in the modified coating adding 50 wt.% Co-based alloy were refined and a lot of Cr23C6 or M23(C, B)6 compounds with fine lamellar feature were formed around austenitic grain boundaries or in the intergranular regions. The contribution of element Co to the modification of Ni35WC coating is that it cannot only promote the formation of more hard compounds to refine austenite grains, but also refine the size of precipitates, and change the phase type of eutectic structure as a result of disappeared Cr boride brittle phases. A noticeable improvement in wear resistance is obtained in the Ni35WC coating with 50 wt.% Co-based alloy, which makes the wear rate decreased by about 53 % and 30% by comparison to that of the substrate and the Ni35WC coating, respectively. It is suggested that the improvement is closely related to the composite coating being strengthened owing to the increase of coating hardness, formation of a fine-grained microstructure caused by Co, and fine hard precipitate phases in the eutectic structure.

MICROSTRUCTURE AND DRY SLIDING WEAR RESISTANCE OF LASER CLADDING Ti-Al-Si COMPOSITE COATING

2017 ◽  
Vol 24 (Supp01) ◽  
pp. 1850009 ◽  
Author(s):  
H. X. ZHANG ◽  
H. J. YU ◽  
C. Z. CHEN ◽  
J. J. DAI
Keyword(s):  
Wear Resistance ◽  
Laser Cladding ◽  
Composite Coatings ◽  
Energy Dispersive Spectrometer ◽  
Wear Test ◽  
Dry Sliding Wear ◽  
Test Machine ◽  
Transmission Microscopy ◽  
Hardness Tester ◽  
Three Samples

In order to improve the wear resistance of Ti alloys, different mass ratios of Ti-Si-Al powders were designed to fabricate hard phases reinforced intermetallic matrix composite coatings on the Ti-6Al-4V substrate by laser cladding. The corresponding coatings were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and high resolution transmission microscopy (HRTEM). The HV-1000 hardness tester and MM200 wear test machine were employed to test the hardness and the wear resistance of the composite coatings, respectively. The composite coatings mainly consisted of the reinforcements of Ti5Si3, Ti3AlC2 and Ti7Al5Si[Formula: see text] and the matrix of Ti3Al, TiAl, TiAl3 and [Formula: see text]-Ti. The micro-hardness of the Ti-35Al-15Si coating was from 956 HV[Formula: see text] to 1130 HV[Formula: see text], which was approximately 3–4 times of the substrate and the highest in the three samples. The wear rate of the Ti-35Al-15Si coating was 0.023[Formula: see text]cm3[Formula: see text][Formula: see text][Formula: see text]min[Formula: see text], which was about 1/4 of the Ti-6Al-4V substrate. It was the lowest in the three samples.

scholarly journals Tribological behavior of ammonium-based protic ionic liquid as lubricant additive

Friction ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 169-178
Author(s):  
Hong Guo ◽  
Patricia Iglesias
Keyword(s):  
Ionic Liquid ◽  
Tribological Behavior ◽  
Low Cost ◽  
Disk Surface ◽  
Optical Microscope ◽  
Friction Reduction ◽  
Proton Nuclear Magnetic Resonance ◽  
Wear Volume ◽  
Wear Properties ◽  
Protic Ionic Liquid

Abstract In this study, the tribological behavior of an ammonium-based protic ionic liquid (PIL) as an additive in a base mineral oil (MO) is investigated on a steel-steel contact at room temperature and 100 °C. Tri-[bis(2-hydroxyethylammonium)] citrate (DCi) was synthesized in a simple and low-cost way, and the ionic structure of DCi was confirmed by proton nuclear magnetic resonance (1H NMR). The stability measurement of 1 wt% DCi to a MO was investigated, and the lubricating ability and anti-wear properties of DCi as an additive in MO were also examined using a custom-designed reciprocating ball-on-flat tribometer. Optical microscope and profilometry were used to obtain the worn morphology of the steel disks. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were carried out to investigate the wear mechanism and to analyze the surface interactions between the rubbing components. When 1 wt% DCi is added into the base MO, frictional performance is improved at both temperatures studied with a friction reduction of 29.0% and 35.5%, respectively. Moreover, the addition of 1 wt% DCi to MO reduced the wear volume 59.4% compared to the use of MO. An oxygen-richened tribolayer is confirmed by EDS on the disk surface when DCi was used as additive under 100 °C.

scholarly journals Black phosphorus quantum dots: A new-type of water-based high-efficiency lubricant additive

Friction ◽  
2020 ◽  
Author(s):  
Weiwei Tang ◽  
Zhiqiang Jiang ◽  
Baogang Wang ◽  
Yufeng Li
Keyword(s):  
Quantum Dots ◽  
High Efficiency ◽  
Lubricant Additive ◽  
Black Phosphorus ◽  
Friction Reduction ◽  
Wear Volume ◽  
Wear Properties ◽  
Water Based ◽  
Black Phosphorus Quantum Dots ◽  
Base Liquid

AbstractBlack phosphorus quantum dots (BPQDs), obtained via a typical solution-based top-down method, were used as water-based lubricant additives. BPQDs exhibited remarkable friction reduction and anti-wear properties even at the ultra-low concentration of 0.005 wt%, which reduced the friction coefficient and wear volume of the base liquid by 32.3% and 56.4%, respectively. In addition, the load-supporting capacity of the base liquid increased from 120 N to over 300 N. BPQDs-based additives exhibited a relatively long lifetime at a relatively high load of 80 N. The performance of BPQDs considerably exceeded that of the BP; this may be attributed to their small and uniform particle size, good dispersion stability in water, and high reactivity at the frictional surfaces. The results of the surface wear resistance analysis demonstrated that a robust tribochemical film with a thickness of approximately 90 nm was formed on the rubbing surface lubricated with 0.005 wt% of BPQDs dispersion. Moreover, the film served as a direct evidence of the excellent tribological performance of BPQDs.

Microstructure and Wear Properties of Laser Synthesized Composite Coatings on Ti-6Al-4V

2012 ◽  
Vol 217-219 ◽  
pp. 1354-1358
Author(s):  
Jin Nan Zhao ◽  
Jing Liang ◽  
Sui Yuan Chen ◽  
Chang Sheng Liu ◽  
Feng Hua Liu
Keyword(s):  
Weight Loss ◽  
Laser Cladding ◽  
Powder Mixture ◽  
Composite Coatings ◽  
Scanning Speed ◽  
Pulse Frequency ◽  
Wear Property ◽  
X Ray Diffraction ◽  
Wear Properties ◽  
Metallurgical Bonding

Ti-6Al-4V, C and TiB2 powders (71.5%Ti-6Al-4V+ 26.2%TiB2+2.3%C in wt. %) were prepasted and then laser clad on Ti-6Al-4V substrates. Laser cladding was carried out with a Nd:YAG pulse laser with the parameters of defocus length 15mm, pulse frequency 15Hz, scanning speed 2-4mm/s, electric current 200-240A. Microstructure and phases were analyzed with the Optical Microscopy(OM), Scanning Electron Microscopy(SEM) and X-Ray Diffraction(XRD). Laser cladding layers with smooth surfaces, good metallurgical bonding with no cracks and pores were formed. The average thickness of the coatings is approximately 80μm. Reactions among Ti, C and TiB2 in the laser molten pool cause in-situ synthesis of TiB, TiB2 and TiC reinforcements. The average microhardness is 836HV, which is more than twice that of the Ti-6Al-4V substrate (320HV). Friction coefficients of the cladding coatings fluctuate between 0.26-0.3. Laser cladding specimen with powder mixture of 71.5%Ti-6Al-4V+ 26.2%TiB2+2.3%C (weight loss 0.0007g after sliding 245m) possesses better wear property than that of the specimen with powder mixture of 90%Ti-6Al-4V+ 10%B4C (weight loss 0.0068g).

MICROSTRUCTURE AND WEAR PROPERTIES OF LASER CLAD TiB2 + TiC/Fe COMPOSITE COATING

2012 ◽  
Vol 19 (05) ◽  
pp. 1250052 ◽  
Author(s):  
X. H. WANG ◽  
M. ZHANG ◽  
B. S. DU ◽  
S. LI
Keyword(s):  
Wear Resistance ◽  
Composite Coating ◽  
Laser Cladding ◽  
Volume Fraction ◽  
Composite Coatings ◽  
Wear Properties ◽  
Friction Coefficients ◽  
Iron Based

Iron-based composite coatings reinforced with TiB2–TiC multiple ceramic have been fabricated from a precursor of B4C , TiO2 and Al powders by laser cladding. The effect of TiO2 and Al on the microstructure and wear properties of the coatings was investigated. The results showed that the volume fraction, type and size of the reinforcements were influenced by the content of TiO2 and Al . TiB2 and TiC were evenly distributed in the coating; however, most of Al2O3 were ejected from the coatings, only few of them retained in the coating acting as nucleation core of reinforcement or inclusion. The microhardness and wear resistance of the coatings were improved, whereas the friction coefficients of the coatings were considerably lower than that of substrate.

scholarly journals Effect of Ni/MoS2 Addition on Microstructure and Properties of Supersonic Plasma-Sprayed Ni-Based Composite Coatings

2021 ◽  
Author(s):  
Xinsheng WANG ◽  
Wenbin HE ◽  
Junjian HOU ◽  
Kun LIU ◽  
Xihao YAN
Keyword(s):  
Friction And Wear ◽  
Composite Coatings ◽  
Tool Material ◽  
Friction Reduction ◽  
Fatigue Performance ◽  
Fatigue Properties ◽  
Wear Properties ◽  
Wear Performance ◽  
Supersonic Plasma ◽  
Plasma Sprayed

Abnormal tool wear is a significant problem encountered in machining. MoS2 has the function of friction reduction; thus, to mitigate friction, two Ni-based coatings, Ni60 and Ni60 + 15 wt.% Ni/MoS2, were obtained on tungsten steel using supersonic plasma technology. The microstructure, phase structure, microhardness, fatigue properties, and friction and wear properties of the two coatings were characterized. The results show that the two plasma-sprayed Ni-based coatings have desirable structures. The addition of Ni-coated MoS2 can effectively improve the hardness of the coatings, with values reaching as high as 735 HV. The speed of rotation of the friction ball was set as 200 r/min, and the cutting force was 201.6 N. The fatigue performance as well as the friction and wear performance of the coating are simulated using ANSYS. The fatigue performance is improved by 12.6 % after adding 15 wt.% Ni/MoS2, and the friction system of the coating becomes stable after 25 min of contact. The addition of 15 wt.% Ni/MoS2 can effectively improve the performance of the tool material.

Plasma Sprayed Self-Lubricating Cr2O3-CaF2 Coatings: Friction and Wear Properties

1998 ◽  
Author(s):  
F. Vos ◽  
L. Delaey ◽  
M. De Bonte ◽  
L. Froyen
Keyword(s):  
Friction And Wear ◽  
Solid Lubricant ◽  
Composite Coatings ◽  
Substrate Surface ◽  
Wear Test ◽  
Ceramic Coatings ◽  
Wear Volume ◽  
Wear Properties ◽  
Wear And Friction ◽  
Friction And Wear Properties

Abstract An alternative production route to obtain thermally sprayed self-lubricating ceramic coatings is proposed and microstructural, friction and wear properties of these coatings are discussed. A preliminary powder treatment shows to induce a higher degree of homogeneity compared to conventionally deposited composite coatings, offering some perspectives for a further improvement of the lubricating and wear properties. This approach is illustrated using CaF2 as a solid lubricant dispersed in a Cr2O3 matrix, where the high melting point of the latter (Tm{Cr2O3} =2460°C) necessitates plasma spraying as deposition technique. The microstructure of the coatings is evaluated by a metallographic study of sections perpendicular and parallel to the substrate surface. Wear and friction behaviour is evaluated using reciprocating wear test Wear tracks are analysed by means of laser profilometry. The results are discussed in relation to test and production parameters. Test temperature as well as solid lubricant concentration predominantly affects the wear and friction properties. Using a surface temperature of 400°C a friction coefficient of 0.25 and a wear volume of 37*103 µm3 after 10.000 cycles are obtained for a coating containing 16 vol.% of CaF2.

Effect of Ultrasonic Vibration on the Friction and Wear Properties of GCr15/45# Steel Frictional Pairs Lubricated by n-Al2O3 Additives

2012 ◽  
Vol 538-541 ◽  
pp. 1920-1923
Author(s):  
Yu Lin Qiao ◽  
Shan Lin Yang ◽  
Yan Zang ◽  
Xin Yu Dong ◽  
Qing Sheng Cui
Keyword(s):  
Friction Coefficient ◽  
Ultrasonic Vibration ◽  
Photoelectron Spectroscopy ◽  
Friction And Wear ◽  
Ball Bearing ◽  
Wear Scar ◽  
Friction Reduction ◽  
Wear Volume ◽  
Wear Properties ◽  
Friction And Wear Properties

The friction and wear properties of GCr15/45# steel frictional pairs lubricated by n- Al2O3 additives under ultrasonic vibration or not were studied. The scanning electron microscope(SEM), X-ray photoelectron spectroscopy(XPS) and energy dispersive spectrometer (EDS) were carried out to analyse the wear scar surface. The effect mechanism of ultrasonic vibration on friction pairs was discussed. The results indicated that ultrasonic vibration could decrease the friction and wear of GCr15/45# friction pairs, when the content of n-Al2O3 was 0.5wt%, the effect of ultrasonic vibration on friction pairs was most obvious. The friction coefficient, wear volume and wear scar depth under ultrasonic vibration decreased 10%, 34% and 13%, respectively. The friction reduction and anti-wear mechanism of n-Al2O3 was single “micro ball bearing” without ultrasonic vibration, and it changed to “micro ball bearing” and adsorption penetration film with ultrasonic vibration, so the friction coefficient and wear volume was reduced.

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