scholarly journals Influence of nano-SiO2 on the bonding strength and wear resistance properties of polyurethane coating

2019 ◽  
Vol 26 (1) ◽  
pp. 77-83 ◽  
Author(s):  
Fangfang Wang ◽  
Lajun Feng ◽  
Huini Ma ◽  
Zhe Zhai ◽  
Zheng Liu

Abstract To improve the wear resistance of polyurethane (PU) coating and its adhesion to the steel substrate, a series of simple and practicable techniques were designed to mix nano-SiO2 with PU powder to cast a coating layer onto the steel. When the addition of nano-SiO2 was small, a network structure of PU-SiO2 was produced. It improved the wear resistance of the composite coating and its adhesion to the steel substrate. When the addition of nano-SiO2 was excessive, agglomerated nano-SiO2 particles not only affected the bond between the PU resin and the steel substrate but also became abrasive materials, intensifying the abrasion of the composite coating during friction. It resulted in lower bonding strength and poorer wear resistance of the composite coating. The wear rate and friction coefficient of 2 wt.% SiO2/PU composite coating were 1.52×10−6 cm3/min N and 0.31, respectively. Its wear resistance was about 10 times as high as that of the pure PU coating. Furthermore, a simple and practicable installation was designed to test the bonding strength between the coating and the steel substrate. The bonding strength between 2 wt.% SiO2/PU composite coating and the steel substrate was 7.33 MPa, which was 39% higher than that of the pure PU coating.

2005 ◽  
Vol 473-474 ◽  
pp. 255-260 ◽  
Author(s):  
T. Sebestyén ◽  
Gábor Buza ◽  
F. Franek ◽  
János Takács ◽  
Zoltán Kálazi ◽  
...  

In this work we intend to investigate the surface properties of laser sintered and coated parts, by measurement of friction coefficient and wear rate. The main aim of this research is to justify laser sintered prototype tools for injection molding of fibre-reinforced polymers. For increase of wear resistance we used hard Co-based and Fe-based coatings on laser-sintered phosphorous bronze and unalloyed steel substrate. Short carbon- and glass-fibre-reinforced polymers were used as counter bodies. For the tribological laboratory model tests a pin-on-disk test rig was used. In case of coated parts – with higher wear resistance – we used a cylinder-on-cylinder tribometer. The tribological properties were determined at different load conditions. Our results show that the friction coefficient and wear resistance of laser treated surfaces are good. The coefficient of friction of coated specimens is slightly less, but the wear rate is significantly less.


Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 651
Author(s):  
Weihua Wang ◽  
Faqin Xie ◽  
Xiangqing Wu ◽  
Zheng Zhu ◽  
Shaoqing Wang ◽  
...  

In order to increase the surface hardness and wear-resistance property of sled track slippers, a Ni80Al20-MoS2 composite coating was fabricated on the surface of a stainless steel 0Cr18Ni9Ti sled track slipper via atmospheric spray and hot dipping. The microstructure, composition and surface hardness of coatings under different spraying powers were characterized and measured. The wear-resistant properties of the slipper substrate and the coating were also checked. The results showed that the higher the spraying power was, the greater the smoothness, density and hardness was of the Ni80Al20 coating, while the thickness initially increased and then decreased. When the spraying power was 18 kW, the thickness was 342.5 μm, the surface hardness was 304.1 Hv0.2, and the coating was composed of Ni, Al, Ni3Al, NiAl and a little Al2O3. The friction coefficient of the slipper substrate against GCr15 balls at room temperature in air was 0.7, while the coated substrate with MoS2 lubrication film was 0.3 and the volume wear rate declined by 1/5. The friction coefficient of the Ni80Al20 coating was 0.5 and the Ni80Al20-MoS2 composite coating was 0.15, while the volume wear rate declined by 1/4 and 1/3.


2015 ◽  
Vol 642 ◽  
pp. 30-33 ◽  
Author(s):  
Jian Liang Li ◽  
Juan Juan Chen ◽  
Dang Sheng Xiong ◽  
Yong Kang Zhang ◽  
Yong Kun Qin ◽  
...  

The graphene containing Ni-based composite coatings with different graphene addition amounts were prepared on 45 steel surface by using dipulse composite electrodeposition technology. The tribological behavior of composite coating was tested by against GCr15 steel pin under the dry condition. The friction coefficient of composite coating is 20-30% lower than pure Cr coating, their wear rates are almost in the same magnitude. Compared with 45 steel, the friction coefficient of composite coating decreases and wear rate falls over 50%.


2010 ◽  
Vol 97-101 ◽  
pp. 1377-1380 ◽  
Author(s):  
Jun Hai Liu ◽  
Ji Hua Huang ◽  
Jun Bo Liu ◽  
Gui Xiang Song

A new type in situ reinforcing phase TiC+Cr7C3 ceramal composite coating was fabricated on substrate of Q235 steel by plasma transferred arc (PTA) weld-surfacing process using the mixture of ferrotitanium, ferrochromium, ferroboron and ferrosilicium powders. Microstructure and wear performance of the coating were investigated by means of X-ray diffraction (XRD), scanning electron micrograph (SEM), energy dispersive X-ray analysis (EDS), microhardness tester and wear tester. Results show that the composite coating consists of TiC, primary phase Cr7C3 , (Cr,Fe)7C3 and austenite. The composite coating is metallurgically bonded to the Q235 steel substrate. TiC particles present cubic and “dendrite flower-like” shape in the composite coating. The coating has high microhardness and excellent wear resistance under dry-sliding wear test conditions.


2010 ◽  
Vol 150-151 ◽  
pp. 1106-1109 ◽  
Author(s):  
Yong Kun Wang ◽  
Li Chen ◽  
Zhi Wei Xu

The glass fiber (GF) reinforced epoxy (EP) composites filled by nano-Al2O3, nano-TiO2, nano-SiO2 and multi-walled carbon nanotubes (MWCNTs) were prepared. The friction and wear behavior of composites under dry condition were evaluated with block-on-ring friction and wear tester. The morphologies of the worn surfaces of the composites were analyzed by scanning electric microscopy (SEM). The results show that 0.5 wt% MWCNTs and nano-TiO2 can significantly lower the friction coefficient and specific wear rate of composites, respectively, while 0.5 wt% nano-SiO2 and nano-Al2O3 can slightly lower the friction coefficient and specific wear rate of the composites.


2016 ◽  
Vol 53 (1) ◽  
pp. 66-74
Author(s):  
J. Lungevics ◽  
A. Leitans ◽  
J. Rudzitis ◽  
N. Bulahs ◽  
P. Nazarovs ◽  
...  

Abstract Carbon-copper composite coatings reinforced with titanium were deposited using high power magnetron sputtering technique. Tribological and metrological tests were performed using Taylor Hobson Talysurf Intra 50 measuring equipment and CSM Instruments ball-on-disk type tribometer. Friction coefficient and wear rate were determined at 2N, 4N, 6N loads. It was revealed that friction coefficient decreased at a higher Ti concentration, which was particularly expressed at bigger applied loads. However, wear volume values tended to increase in the beginning, till Ti concentration reached about 11 %, but then decreased, thus providing better nanocoating wear resistance.


2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Dongya Zhang ◽  
Zhongwei Li ◽  
Feng Gao ◽  
Xian Wei ◽  
Yuquan Ni

Abstract In this study, composite coatings of polyvinylidene fluoride (PVDF) and epoxy resin deposited with La2O3 and MoS2 nanoparticles on the surface of a Babbitt alloy have been studied in order to improve its tribological performance. A pin-on-disc tribometer was used to evaluate the tribological properties of the Babbitt alloys with and without the composite coatings. The results showed that compared with the polymer-La2O3 composite coating, the polymer-MoS2 composite coating was more effective in reducing the friction coefficient and the wear rate of the Babbitt substrate under both dry and boundary lubrication conditions compared with the polymer-La2O3 composite coating. However, the wear rate of the Babbitt alloy with the polymer-La2O3 composite coating was lower than that of the alloy with the polymer-MoS2 composite coating. The wear scratches were analyzed using a scanning electron microscope (SEM). The worn surface of the polymer-La2O3 coating was much smoother and more continuous than that of the polymer-MoS2 coating, meanwhile transfer films were respectively detected on the pin surfaces. The addition of nanoparticles can reduce the wear rate and friction coefficient of polymer composite coating by forming a transfer film. Hence, the polymer composite coating can protect the Babbitt substrate.


2019 ◽  
Vol 71 (9) ◽  
pp. 1064-1071 ◽  
Author(s):  
Alagarsamy S.V. ◽  
Ravichandran M.

Purpose Aluminium and its alloys are the most preferred material in aerospace and automotive industries because of their high strength-to-weight ratio. However, these alloys are found to be low wear resistance. Hence, the incorporation of ceramic particles with the aluminium alloy may be enhanced the mechanical and tribological properties. The purpose of this study is to optimize the specific wear rate and friction coefficient of titanium dioxide (TiO2) reinforced AA7075 matrix composites. The four wear control factors are considered, i.e. reinforcement (Wt.%), applied load (N), sliding velocity (m/s) and sliding distance (m). Design/methodology/approach The composites were fabricated through stir casting route with varying weight percentages (0, 5, 10 and 15 Wt.%) of TiO2 particulates. The mechanical properties of the composites were studied. The specific wear rate and friction coefficient of the newly prepared composites was determined by using a pin-on-disc apparatus under dry sliding conditions. Experiments were planned as per Taguchi’s L16 orthogonal design. Signal-to-noise ratio analysis was used to find the optimal combination of parameters. Findings The mechanical properties such as yield strength, tensile strength and hardness of the composites significantly improved with the addition of TiO2 particles. The analysis of variance result shows that the applied load and reinforcement Wt.% are the most influencing parameters on specific wear rate and friction coefficient during dry sliding conditions. The scanning electron microscope morphology of the worn surface shows that TiO2 particles protect the matrix from more removal of material at all conditions. Originality/value This paper provides a solution for optimal parameters on specific wear rate and friction coefficient of aluminium matrix composites (AMCs) using Taguchi methodology. The obtained results are useful in improving the wear resistance of the AA7075-TiO2 composites.


2019 ◽  
Vol 25 (3) ◽  
pp. 252-258
Author(s):  
Geng TIANYUAN ◽  
Cunshan WANG

Ni-based alloy cladding layers with different graphene sheet additions were prepared by laser cladding on the 40CrNi2Si2MoV steel substrate. The influence of the graphene sheet on the microstructure and properties of the cladding layers was investigated. The results show that owing to the diffusion-reaction dissolution, the graphene sheet addition does not bring a corresponding change in the phase constitutions of the cladding layers, i. e., the cladding layers are still composed of γ-Ni, Ni3B, and M7C3 phases. But what has changed is that the solidified structure is refined, and the volume fractions of the eutectic and the carbide are increased with the increase of graphene sheet addition. As a result, the hardness and the wear resistance of the cladding layers gradually increase, whereas the friction coefficient firstly decreases and then increases, with the lowest friction coefficient obtained at 0.5 vol.% graphene sheet addition. Compared to the Ni-based alloy cladding layers with micro-size graphite additions, the studied cladding layers exhibit improved hardness and wear resistance, good forming quality, and increased friction coefficient. DOI: http://dx.doi.org/10.5755/j01.ms.25.3.19173


Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1805
Author(s):  
Yu ◽  
Zhang ◽  
Tang ◽  
Gao

(1) In order to improve the properties of antifriction and wear resistance of polyimide (PI) composite under high temperature conditions, (2) 3-Aminopropyltriethoxysilane (APTES) and Lanthanum (La) salt modifications were employed to manufacture poly-p-phenylenebenzobisoxazole (PBO)/PI composites with different interface properties. The representative ambient temperatures of 130 and 260 °C were chosen to study the friction and wear behavior of composites with different interface properties. (3) Results revealed that while both modification methods can improve the chemical activity of the surface of PBO fibers, the La salt modification is more effective. The friction coefficient of all composites decreases with the increase of sliding velocity and load at two temperatures, and the specific wear rate is increases. Contrary to the situation in the 130 °C environment, the wear resistance of the unmodified composite in the 260 °C environment is greatly affected by the sliding velocity and load, while the modified composites are less affected. Under the same test parameters, the PBO–La/PI composite has the lowest specific wear rate and friction coefficient, and (4) La salt modification is a more effective approach to improve the properties of antifriction and wear resistance of PI composite than APTES modification in high ambient temperatures.


Sign in / Sign up

Export Citation Format

Share Document