Microstructure and Wear Characterization of Selflubricating Al2O3 - MoS2 Composite Ceramic Coatings

1988 ◽  
Vol 140 ◽  
Author(s):  
K.A. Koshkarian ◽  
W.M. Kriven
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Crystallographic Orientation ◽  
Composite Ceramic ◽  
Ceramic Coatings ◽  
Molten State ◽  
Alumina Coatings ◽  
Pure Alumina ◽  
Wear Characterization

AbstractComposite ceramic coatings of alumina (A1203) containing some molybdenum disulfide (MoS2) were electro-codeposited on to Al metal substrates by a combination of anodic sparks deposition of A1203 and electrophoresis of MoS2. The microstructures were characterized by XRD, XPS, SEM, EDS, SNMS,TEM, SAD and relative wear resistance measurements. The coatings consisted mostly ofa-A1203 with some γ and βpresent as well. The coatings were porous and microcracked. SEM showed them to consist of circular “splats” which had rapidly crystallized from the molten state in areas ofdielectric breakdown in the coating. In the TEM the microstructure was seento contain “sets” of parallel, elongated grains having a single crystallographic orientation. The grains were separated by dislocated, low angle grain boundaries or microcracks. The sets intersected at irregularly curved interfaces and were mechanically interlocked. Quantitative SNMS indicated that up to 26 wt% MoS2 was incorporated in coatings fabricated from 5g\1 solutions. SEM\EDS as well as TEM\SAD\EDS identified 1-3μm particles of MoS2 incorporated into the 5g\1 solution derived coatings. These coatings exhibited a 50% lower wear rate than pure alumina coatings deposited under the same conditions.

Deposition and Characterization of D-Gun Sprayed WC-Co Coating with Self-Lubricating Property

2007 ◽  
Vol 544-545 ◽  
pp. 215-218
Author(s):  
Hao Du ◽  
Chao Sun ◽  
Jun Gong ◽  
Soo Wohn Lee
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Sliding Wear ◽  
Friction And Wear ◽  
Wear Track ◽  
Wear Property ◽  
Ni Powder ◽  
Lubricating Property ◽  
Detonation Gun

A WC-Co coating with self-lubricating property was deposited by detonation gun (D-gun) process, using a WC-Co powder doped with a MoS2-Ni powder, under a proper spray condition. It is proved that the MoS2 composition was kept in the resulting coating by SEM, XRD and EPMA. Evaluation on sliding wear property indicates that the MoS2 composition plays an important role in lowering both coefficient of friction and wear rate for the resulting coating, which is confirmed by observations on wear track. It suggests that the deposition of WC-Co coating with self-lubricating property by D-gun spray is feasible by controlling lubricant powder and spray conditions, which can exhibit higher sliding wear resistance.

scholarly journals Microstructure and Wear Behaviors of Plasma-Sprayed MoAlB Ceramic Coating

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 474
Author(s):  
Fuzhu Li ◽  
Shengnan Sun ◽  
Yong Xu ◽  
Lihui Tian ◽  
Yun Wang ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Plasma Spraying ◽  
Ceramic Coating ◽  
Adhesive Wear ◽  
Ceramic Coatings ◽  
Atmospheric Plasma ◽  
Wear Rates ◽  
Arc Power ◽  
Plasma Sprayed

MoAlB ceramic coatings were prepared on a 316 steel surface by atmospheric plasma spraying with different arc power levels. The phase composition, microstructure and wear resistance of coatings against GCr15 and Si3N4 counterparts were studied. The MoAlB ceramic decomposed and was oxidized to form MoB and Al2O3 during plasma spraying. With the increase of the arc power, MoAlB experienced more decomposition, but the coatings became denser. When the arc power increased from 30 to 36 kW, the wear rates of coatings against GCr15 and Si3N4 balls reduced by 91% and 78%, respectively. The characterization of wear tracks shows that when against GCr15 counterparts, the main wear mechanisms are abrasive and adhesive wear, and when against Si3N4 counterparts, fatigue and abrasive wear are dominant. The refinement of wear resistance by increasing arc power can be attributed to the improvement of density and adhesive strength among splats.

scholarly journals Tribological Behavior of Al2O3-MoO2-SiO2 Composite Ceramic Coating on Al-Zn-Mg-Cu Alloy

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 915
Author(s):  
Diping Zeng ◽  
Zhiyi Liu ◽  
Lihua Zou ◽  
Haijiang Wu
Keyword(s):  
Wear Resistance ◽  
Tribological Behavior ◽  
Composite Coatings ◽  
Sodium Molybdate ◽  
Wear Test ◽  
Composite Ceramic ◽  
Ceramic Coatings ◽  
Wear Properties ◽  
Mullite Phase ◽  
Cu Alloy

In order to enhance wear properties of Al-Zn-Mg-Cu alloy parts, Al2O3-MoO2-SiO2 composite ceramic coatings are formed on Al-Zn-Mg-Cu alloy by the DC micro-arc oxidation (MAO) method in the silicate electrolyte with sodium molybdate. Effects of sodium molybdate concentration on the structure characteristics and wear resistance of the composite ceramic coatings are analyzed by scanning electron microscopy, X-ray diffraction and the wear test, respectively. Analyses indicate that the composite coating consists of different states of Al2O3, MoO2 and mullite phase. With the addition of molybdate in the electrolyte, the morphology and structure are changed. The tribological behavior is greatly affected by the surface characteristics and hardness of the coatings. The composite coatings formed by adding 3 g/L of sodium molybdate electrolyte have the best wear resistance.

Increasing in wear resistance of excavating machine elements

2020 ◽  
pp. 306-308
Author(s):  
V.S. Bochkov
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Thermomechanical Treatment ◽  
Cold Work ◽  
Hadfield Steel ◽  
Outer Side ◽  
Viii And Ix ◽  
Machine Elements ◽  
The Impact

The relevance of the search for solutions to increase the wear resistance of bucket teeth of excavating machine type front shovel is analyzed. The reasons for the wear of the teeth are considered. It is determined that when excavating machines work for rocks of VIII and IX categories, impact-abrasive wear of the inner side of the teeth and abrasive external wear occurs. It is proved that the cold-work hardening of Hadfield steel (the teeth material), which occurs during the excavating machine teeth work in the rocks of VIII and IX categories, reduces the impact-abrasive wear rate on the inner side of the teeth and does not affect the abrasive wear of the outer. The methods for thermomechanical treatment of the outer side of the excavating machine tooth is proposed. It can increase the wear resistance of Hadfield steel (110G13L) up to 1.7 times and lead to the self-sharpening effect of the tooth due to equalization of the wear rate of the outer and inner parts of the tooth. The efficiency factor of thermomechanical treatment to reduce the of abrasive wear rate of Hadfield steel is experimentally proved.

scholarly journals A Comprehensive Investigation on 3D Printing of Polyamide 11 and Thermoplastic Polyurethane via Multi Jet Fusion

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2139
Author(s):  
Wei Shian Tey ◽  
Chao Cai ◽  
Kun Zhou
Keyword(s):  
Tensile Strength ◽  
Flexural Strength ◽  
Wear Rate ◽  
Mechanical Performance ◽  
Thermoplastic Polyurethane ◽  
Print Quality ◽  
Polyamide 11 ◽  
Powder Bed

Multi Jet Fusion (MJF) is a recently developed polymeric powder bed fusion (PBF) additive manufacturing technique that has received considerable attention in the industrial and scientific community due to its ability to fabricate functional and complex polymeric parts efficiently. In this work, a systematic characterization of the physicochemical properties of MJF-certified polyamide 11 (PA11) and thermoplastic polyurethane (TPU) powder was conducted. The mechanical performance and print quality of the specimens printed using both powders were then evaluated. Both PA11 and TPU powders showed irregular morphology with sharp features and had broad particle size distribution, but such features did not impair their printability significantly. According to the DSC scans, the PA11 specimen exhibited two endothermic peaks, while the TPU specimen exhibited a broad endothermic peak (116–150 °C). The PA11 specimens possessed the highest tensile strength in the Z orientation, as opposed to the TPU specimens which possessed the lowest tensile strength along the same orientation. The flexural properties of the PA11 and TPU specimens displayed a similar anisotropy where the flexural strength was highest in the Z orientation and lowest in the X orientation. The porosity values of both the PA11 and the TPU specimens were observed to be the lowest in the Z orientation and highest in the X orientation, which was the opposite of the trend observed for the flexural strength of the specimens. The PA11 specimen possessed a low coefficient of friction (COF) of 0.13 and wear rate of 8.68 × 10−5 mm3/Nm as compared to the TPU specimen, which had a COF of 0.55 and wear rate of 0.012 mm3/Nm. The PA11 specimens generally had lower roughness values on their surfaces (Ra < 25 μm), while the TPU specimens had much rougher surfaces (Ra > 40 μm). This investigation aims to uncover and explain phenomena that are unique to the MJF process of PA11 and TPU while also serving as a benchmark against similar polymeric parts printed using other PBF processes.

Microstructure and Grain Abrasion Properties of Cr3C2-NiCr Coating Prepared by Laser Cladding Method

2012 ◽  
Vol 271-272 ◽  
pp. 3-7
Author(s):  
Long Wei ◽  
Zong De Liu ◽  
Xin Zhi Li ◽  
Ming Ming Yuan ◽  
Cheng Yuan Zhong
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Laser Cladding ◽  
Micro Hardness ◽  
High Quality ◽  
Wear Resistant ◽  
Hardness Tester ◽  
Technology Analysis ◽  
Main Component

Cr3C2-NiCr has high quality of wear resistant properties and is widely used in abrasive environment. In this paper, Cr3C2-NiCr coating was prepared on 45 steel by laser cladding technology. Analysis and research of the coatings were achieved by SEM and XRD to determine the main component and the different region on coatings. The hardness and the element component were investigated by micro-hardness tester and EDS. Abrasion tests were performed to contrast the wear resistance of two materials. The results indicate that the hardness of the coatings is nearly 3 times as the substrate. The coatings are well combined with the substrate and the phase of Cr3C2 has a large proportion in the coatings. Abrasion tests show that the average of wear rate on substrate is 5.2 times as the coatings.

Wear Behavior and Structural Characterization of a Nitrogen Implanted Ti6Al4V Alloy at Different Temperatures

1983 ◽  
Vol 27 ◽  
Author(s):  
R. Martinella ◽  
G. Chevallard ◽  
C. Tosello
Keyword(s):  
Wear Resistance ◽  
Structural Characterization ◽  
Wear Behavior ◽  
Hardened Layer ◽  
Structural Modifications ◽  
Theory Comparison ◽  
Different Temperatures ◽  
Nitrogen Ions ◽  
Wear Tests

ABSTRACTMechanically polished Ti6Al4V samples were implanted with 100 key nitrogen ions to a fluence of 5.1017 ions/cm2 at two different bulk tenneratures: 370°C and 470°C. Wear tests were carried out with a reciprocating slidina tribotester. Structural modifications and wear morphologies were studied by TEM and SEM. 370°C implanted sample showed the same wear behavior as unimplanted ones, while 470°C implanted sample showed better wear resistance because of a TiN hardened layer. Correlations- between microstructural modifications, wear behavior and mechanisms are reported: results agree with the delamination theory. Comparison with ion- and gas-nitrided samples are presented.

Laser Sintering of Nano-Al2O3 Powders on Plasma Sprayed Ceramic Based Coatings

2007 ◽  
Author(s):  
Lida Shen ◽  
Yinhui Huang ◽  
Zongjun Tian ◽  
Guoran Hua
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Plasma Spraying ◽  
Bond Coat ◽  
Continuous Wave ◽  
Ceramic Coatings ◽  
Laser Sintering ◽  
Al2o3 Ceramic ◽  
Plasma Sprayed ◽  
Steel Substrates

This paper describes an investigation of nano-Al2O3 powders reinforced ceramic coatings, which has included NiCrAl and Al2O3+13%wt.TiO2 coats pre-produced by atmosphere plasma spraying, implemented by laser sintering. Commercial NiCrAl powders were plasma sprayed onto 45 Steel substrates to give a bond coat with thickness of ∼100μm. The 600μm thick Al2O3+13%wt.TiO2 based coating was also plasma sprayed on top of the NiCrAl bond coat. With 2.5kw continuous wave CO2 laser, nano-Al2O3 ceramic powders were laser sintered on the based Coatings. The micro structure and chemical composition of the modified Al2O3+13%wt.TiO2 coatings were analyzed by such detection devices as scanning electronic microscope (SEM) and x-ray diffraction (XRD). Microhardness, wear resistance and corrosion resistance of the modified coatings were also tested and compared with that of the unmodified. The results show that the crystal grain size of Al2O3 had no obvious growth. In addition, due to the nanostructured Al2O3 ceramic phases, the coatings exhibited higher microhardness, better wear resistance and corrosion resistance than those unmodified counterparts. The complex process of plasma spraying with laser sintering as a potential effective way of the application of ceramic nano materials was also simply discussed and summarized in the end.

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