scholarly journals Enhanced Mechanical and Tribological Capabilities of a Silicon Aluminum Alloy with an Electroplated Ni–Co–P/Si3N4 Composite Coating

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 120
Author(s):  
Zhijie Li ◽  
Fei Ma ◽  
Dongshan Li ◽  
Shanhong Wan ◽  
Gewen Yi ◽  
...  
Keyword(s):  
Abrasive Wear ◽  
Composite Coating ◽  
Composite Coatings ◽  
Engine Oil ◽  
Si Substrate ◽  
Wear Performance ◽  
Cobalt Layer ◽  
Hard Chrome ◽  
Electroplating Process ◽  
Hardness Values

Ni–Co–P/Si3N4 composite coatings were fabricated over an aluminum–silicon (Al–Si) substrate using a pulse-current electroplating process, in which the rapid deposition of an intermediate nickel–cobalt layer was used to improve coating adhesion. The microstructure, mechanical, and tribological behaviors of the electroplated Ni–Co–P/Si3N4 composite coating were characterized and evaluated. The results revealed that the electroplated Ni–Co–P/Si3N4 composite coating primarily consisted of highly crystalline Ni–Co sosoloid and P, and a volumetric concentration of 7.65% Si3N4. The electroplated Ni–Co–P/Si3N4 composite coating exhibited hardness values almost two times higher than the uncoated Al–Si substrate, which was comparable to hard chrome coatings. Under lubricated and dry sliding conditions, the electroplated Ni–Co–P/Si3N4 composite coating showed excellent anti-wear performance. Whether dry or lubricated with PAO and engine oil, the composite coating showed minimum abrasive wear compared to the severe adhesive wear and abrasive wear observed in the Al–Si substrate.

Wear Performance of the Plasma Sprayed Fine WC-Co Composite Powders Coatings

2012 ◽  
Vol 454 ◽  
pp. 144-147
Author(s):  
Lian Wei Yang ◽  
Jin Hui Li ◽  
Yun Dong ◽  
Xiao Ping Lin
Keyword(s):  
Wear Resistance ◽  
Brittle Fracture ◽  
Composite Coating ◽  
Plasma Spraying ◽  
Composite Coatings ◽  
Composite Powders ◽  
Wear Performance ◽  
Wear And Friction ◽  
Plasma Sprayed ◽  
Increasing Load

WC/Co; Composite coating; Plasma spraying; Friction and wear Abstract: WC- Co composite powders were synthesized by direct mechanical grinding in a rotary-vibration mill under 8h, and then analyzed by SEM and XRD. WC and WC/Co composite coatings were prepared by supersonic plasma spraying fine WC-Co composite powders. The wear and friction properties of both coatings were evaluated. The results showed that the wear resistance of the WC/Co composite coating was superior to that of the WC coating. The improvement in wear resistance of the WC/Co composite coating was attributed to its higher fracture toughness and adhesion strength as well as better thermal diffusivity. As for the WC/Co composite coating, the mechanism was mainly adhesion with micro-abrasion and fatigued-induced brittle fracture within splats, and the delamination along splat boundaries only occurred at high load. However, the failure of the WC coating was predominantly detachment of transferred film and brittle fracture within the splats and delamination along splat boundaries, which were enhanced with the increasing load.

scholarly journals Enhanced Wear Performance of Cu-Carbon Nanotubes Composite Coatings Prepared by Jet Electrodeposition

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 392 ◽  
Author(s):  
Dongdong Ning ◽  
Ao Zhang ◽  
Hui Wu
Keyword(s):  
Carbon Nanotubes ◽  
Surface Morphology ◽  
Composite Coating ◽  
Composite Coatings ◽  
Sodium Dodecyl ◽  
Wear Test ◽  
Uniform Electric Field ◽  
Wear Performance ◽  
Jet Electrodeposition ◽  
Pure Cu

Cu-carbon nanotubes (CNTs) composite coatings with high CNT content and uniformly distributed CNTs were successfully prepared via jet electrodeposition. Pristine CNTs, without any treatment like acid functionalization, were used. Anionic surfactant sodium dodecyl sulfate (SDS) was used to increase the wettability of the CNTs and improve the content of incorporated CNTs. With an appropriate SDS concentration (300 mg/L) in the electrolyte, the incorporated CNT content is as high as 2.84 wt %, much higher than the values reported using conventional electrodeposition (0.42–1.05 wt %). The high-content CNTs were uniformly distributed in the composite coating. The surface morphology of this composite coating (2.84 wt % CNTs) was flat due to the uniform electric field in jet electrodeposition. In the wear test a with load of 1 N and sliding speed of 0.02 m/s, the wear rate of this composite coating was 1.3 × 10−2 mg/Nm, 85.4% lower than that of pure Cu. The enhanced wear performance of Cu-CNTs composite coatings can be attributed to high CNT content and flat surface morphology.

A New Approach of Abrasive Wear Performance of Flame Sprayed NiCrSiBFeC/SiC Composite Coating

Wear ◽  
2021 ◽  
pp. 203887
Author(s):  
Hipólito Carvajal Fals ◽  
Denilson Aguiar ◽  
Leonardo Fanton ◽  
Maria Júlia Xavier Belém ◽  
Carlos Roberto Camello Lima
Keyword(s):  
Abrasive Wear ◽  
Composite Coating ◽  
Wear Performance ◽  
New Approach

Preparation and tribological properties of MoS2/graphite composite coatings modified by La2O3

2018 ◽  
Vol 70 (8) ◽  
pp. 1422-1430
Author(s):  
Ming Qiu ◽  
Rui Zhang ◽  
Yingchun Li ◽  
Hui Du ◽  
Xiao Xu Pang
Keyword(s):  
Service Life ◽  
Abrasive Wear ◽  
Composite Coating ◽  
Tribological Properties ◽  
Wear Mechanisms ◽  
Adhesive Wear ◽  
Composite Coatings ◽  
The Self ◽  
Graphite Composite ◽  
Content Type

PurposeThe MoS2/graphite composite coatings modified by La2O3through spraying technique were successfully prepared on the inner rings of spherical plain bearings. As a comparison, unmodified coatings were also prepared. This paper aims to study the La-modified MoS2/graphite composite coating experimentally and improve the tribological performance of self-lubricating spherical plain bearings.Design/methodology/approachThe performance of La2O3toward the friction coefficient, temperature rise and wear rate of the coatings was studied by a self-made tribo-tester under different swing cycles. And the texture, surface morphology and element composition of the coatings were characterized by scanning electron microscope, energy dispersive spectroscopy and X-ray diffractometry.FindingsThe additives La2O3refined the coatings’ microstructure and improved the tribological properties of the coatings. The oxidation of Mo + 4 to Mo + 6 was effectively inhibited. And the amount of abrasive grains, peeling pits and local cracks on the coatings surface decreased and homogeneous lubricating films formed, which were attributed to the existence of La2O3. The wear mechanisms of unmodified coatings were severe abrasive wear, adhesive wear and delamination wear. However, it exhibited superior wear resistance of the La-modified coatings to unmodified coatings, presenting slight abrasive wear and adhesive wear. The service life of bearings was prolonged under the protection of the modified coatings.Originality/valueThe paper proposed a new modified MoS2/Graphite composite coating for the self-lubricating spherical plain bearings. The investigation on the friction, wear and temperature increase behaviors and the wear mechanisms of the coatings are beneficial to prolonging the service life of the self-lubricating spherical plain bearings.

scholarly journals Influence of Pulse Current Forward-Reverse Duty Cycle on Structure and Performance of Electroplated W–Cu Composite Coatings

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1233
Author(s):  
Yuchao Zhao ◽  
Nan Ye ◽  
Haiou Zhuo ◽  
Chaolong Wei ◽  
Weiwei Zhou ◽  
...  
Keyword(s):  
Composite Coating ◽  
Duty Cycle ◽  
Electrode Materials ◽  
Pulse Current ◽  
Electrical Discharge Machining ◽  
Composite Coatings ◽  
Electrical Contact ◽  
Pulse Plating ◽  
Fusion Welding ◽  
Raw Material

Tungsten-copper (W–Cu) composites are widely used as electrical contact materials, resistance welding, electrical discharge machining (EDM), and plasma electrode materials due to their excellent arc erosion resistance, fusion welding resistance, high strength, and superior hardness. However, the traditional preparation methods pay little attention to the compactness and microstructural uniformity of W–Cu composites. Herein, W–Cu composite coatings are prepared by pulse electroplating using nano-W powder as raw material and the influence of forward-reverse duty cycle of pulse current on the structure and mechanical properties is systematically investigated. Moreover, the densification mechanism of the W–Cu composite coating is analyzed from the viewpoints of forward-pulse plating and reverse-pulse plating. At the current density (J) of 2 A/dm2, frequency (f) of 1500 Hz, forward duty cycle (df) of 40% and reverse duty cycle (dr) of 10%, the W–Cu composite coating rendered a uniform microstructure and compact structure, resulting in a hardness of 127 HV and electrical conductivity of 53.7 MS/m.

scholarly journals Preparation and Degradation Characteristics of MAO/APS Composite Bio-Coating in Simulated Body Fluid

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 667
Author(s):  
Zexin Wang ◽  
Fei Ye ◽  
Liangyu Chen ◽  
Weigang Lv ◽  
Zhengyi Zhang ◽  
...  
Keyword(s):  
Simulated Body Fluid ◽  
Composite Coating ◽  
Body Fluid ◽  
Composite Coatings ◽  
Degradation Process ◽  
Ceramic Coatings ◽  
Immersion Test ◽  
Substrate Material ◽  
Atmospheric Plasma

In this work, ZK60 magnesium alloy was employed as a substrate material to produce ceramic coatings, containing Ca and P, by micro-arc oxidation (MAO). Atmospheric plasma spraying (APS) was used to prepare the hydroxyapatite layer (HA) on the MAO coating to obtain a composite coating for better biological activity. The coatings were examined by various means including an X-ray diffractometer, a scanning electron microscope and an energy spectrometer. Meanwhile, an electrochemical examination, immersion test and tensile test were used to evaluate the in vitro performance of the composite coatings. The results showed that the composite coating has a better corrosion resistance. In addition, this work proposed a degradation model of the composite coating in the simulated body fluid immersion test. This model explains the degradation process of the MAO/APS coating in SBF.

Evaluation of Slurry Erosive Wear Performance of Plasma-Sprayed Flyash-TiO2 Composite Coatings

2021 ◽  
Vol 7 (3) ◽  
Author(s):  
R. Keshavamurthy ◽  
B. E. Naveena ◽  
C. S. Ramesh ◽  
M. R. Haseebuddin
Keyword(s):  
Composite Coatings ◽  
Erosive Wear ◽  
Wear Performance ◽  
Plasma Sprayed

scholarly journals Isothermal Oxidation Performance of Laser Cladding Assisted with Preheat (LCAP) Tribaloy T-800 Composite Coatings Deposited on EN8

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 843
Author(s):  
Sipiwe Trinity Nyadongo ◽  
Sisa Lesley Pityana ◽  
Eyitayo Olatunde Olakanmi
Keyword(s):  
Iron Oxide ◽  
Composite Coating ◽  
Laser Cladding ◽  
Composite Coatings ◽  
Parabolic Rate Constant ◽  
Mass Gain ◽  
Isothermal Oxidation ◽  
Operational Parameters ◽  
Temperature Oxidation ◽  
Service Environments

It is anticipated that laser cladding assisted with preheat (LCAP)-deposited Tribaloy (T-800) composite coatings enhances resistance to structural degradation upon exposure to elevated-temperature oxidation service environments. The oxidation kinetics of LCAP T-800 composite coatings deposited on EN8 substrate and its mechanisms have not been explored in severe conditions that are similar to operational parameters. The isothermal oxidation behaviour of the T-800 composite coating deposited on EN8 via LCAP was studied at 800 °C in air for up to 120 h (5 × 24 h cycles) and contrasted to that of uncoated samples. The mass gain per unit area of the coating was eight times less than that of the uncoated EN8 substrate. The parabolic rate constant (Kp) for EN8 was 6.72 × 10−12 g2·cm−4·s−1, whilst that for the T-800 composite coating was 8.1 × 10−13 g2·cm−4·s−1. This was attributed to a stable chromium oxide (Cr2O3) layer that formed on the coating surface, thereby preventing further oxidation, whilst the iron oxide film that formed on the EN8 substrate allowed the permeation of the oxygen ions into the oxide. The iron oxide (Fe2O3) film that developed on EN8 spalled, as evidenced by the cracking of oxide when the oxidation time was greater than 72 h, whilst the Cr2O3 film maintained its integrity up to 120 h. A parabolic law was observed by the T-800 composite coating, whilst a paralinear law was reported for EN8 at 800 °C up to 120 h. This coating can be used in turbine parts where temperatures are <800 °C.

Sign in / Sign up

Export Citation Format

Share Document