Tribological Properties of PTFE Nanocomposites Filled with Alumina Nanoparticles

2012 ◽  
Vol 557-559 ◽  
pp. 534-537 ◽  
Author(s):  
Yong Ping Niu ◽  
Sa Li ◽  
Jun Kai Zhang ◽  
Li Hua Cai ◽  
Yong Zhen Zhang
Keyword(s):  
Wear Resistance ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Tribological Properties ◽  
Wear Behavior ◽  
Alumina Nanoparticles ◽  
Test Rig ◽  
Scanning Electron ◽  
Worn Surfaces

Polytetrafluoroethylene (PTFE) nanocomposites filled with alumina nanoparticles were prepared by compression molding and follow-up sintering. The tribological behaviors of PTFE nanocomposites sliding against GCr15 steel were evaluated using ball-on-disk tribology test rig. The worn surfaces of the unfilled and filled PTFE nanocomposite were investigated using a scanning electron microscope (SEM). The wear behavior of the PTFE nanocomposites was explained in terms of the topography of worn surfaces. It was found that the addition of alumina nanoparticles was effective in enhancing the wear resistance of the PTFE nanocomposite.

EFFECT OF La2O3 ADDITION ON MICROSTRUCTURE AND WEAR BEHAVIOR OF ELECTROSPARK DEPOSITED Ni-BASED COATINGS

2013 ◽  
Vol 20 (06) ◽  
pp. 1350060 ◽  
Author(s):  
GAO YUXIN ◽  
YI JIAN
Keyword(s):  
Wear Resistance ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Wear Behavior ◽  
Deposition Technique ◽  
Electrospark Deposition ◽  
X Ray ◽  
Wear Process ◽  
Hardness Tester ◽  
Scanning Electron

La 2 O 3 doped Ni -based coatings have been prepared by electrospark deposition technique. The effect of La 2 O 3 on the microstructure, hardness and wear behavior of the as-prepared Ni -based coatings is investigated by using X-ray diffractometer, scanning electron microscope, wear tribometer and Vickers hardness tester. Results indicates that the microstructure, hardness and wear resistance of La 2 O 3 doped Ni -based coatings are effectively improved as compared to the undoped one, and the coating with the addition of 2.5 wt.% La 2 O 3 shows the optimal improvement effects. The addition of La 2 O 3 can reduce the defects, refine grains and increase hardness of the coating, which can inhibit the nucleation and propagation of cracking, consequently resist cutting and fracture during the wear process. Moreover, the addition of La 2 O 3 leads to changes in abrasion mechanism of the coatings, and the reasons resulting in different abrasion mechanisms are discussed.

Tribological Properties of the Overbased Calcium Sulfonate Complex Greases

2011 ◽  
Vol 130-134 ◽  
pp. 891-894 ◽  
Author(s):  
Zhen Zhong Wen ◽  
Yan Qiu Xia ◽  
Xin Feng
Keyword(s):  
Wear Resistance ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Tribological Properties ◽  
Low Noise ◽  
High Load ◽  
Low Friction ◽  
Friction Tester ◽  
Calcium Sulfonate ◽  
Scanning Electron

The commercial greases for bearing applications should meet the requirements of the severe conditions of use (high load, low friction and low noise etc.). A kind of overbased calcium sulfonate complex greases was evaluated using an UMT-II friction tester, the commercial lithium greases as reference. The morphologies of the worn surfaces were observed using a scanning electron microscope (SEM). The results show that the overbased calcium sulfonate complex greases have stable friction coefficients as low as 0.090-0.094. At the same time, the overbased calcium sulfonate complex greases exhibited higher wear resistance than that of commercial lithium greases.

Investigating the structure, adhesion and tribological properties of Al and Zr-doped TiN coatings with various substrate bias voltage and working pressure

2020 ◽  
pp. 135065012094007
Author(s):  
Yaşar Sert ◽  
Tevfik Küçükömeroğlu ◽  
İhsan Efeoğlu
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Tribological Properties ◽  
Surface Hardness ◽  
Closed Field ◽  
X Ray Diffraction ◽  
Working Pressure ◽  
Substrate Bias Voltage ◽  
X Ray ◽  
Scanning Electron

In this study, TiAlZrN films were coated on the hardened 1.2344 (X 40 CrMoV 5 1) steels using DC power supplied closed field unbalanced magnetron sputtering (CFUBMS) technique. Structural investigations of coatings were carried out using scanning electron microscope and X-ray diffraction. The thickness of coatings was measured from the cross-sectional scanning electron microscope images, and the grain size value and residual stress were calculated by using X-ray diffraction data in the Scherrer formula. Nano indentation method was used to investigate the surface hardness for reducing the substrate effect due to very thin coating thickness (∼2–3 µm). Scratch test was performed for determining the adhesion strength of the coatings. As a tribo-test, a ball-on-disk system was used. From the results, it was understood why TiAlZrN coatings were attractive. The highest hardness was observed as 50.67 GPa, and the highest scratch resistance was reached to 56 N. Also, it was determined that the coating having the highest tribological properties (5.46 × 10−5 mm3/Nm) increased the wear resistance of the substrate six times (3.06 × 10−4 mm3/Nm).

INFLUENCE OF TEMPERING ON THE MICROSTRUCTURE PERFORMANCE OF THE LASER-TREATED COATINGS ON 45 STEEL

2013 ◽  
Vol 20 (05) ◽  
pp. 1350048 ◽  
Author(s):  
Xiaodong Hu ◽  
Yajiang Li
Keyword(s):  
Residual Stress ◽  
Wear Resistance ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Steel Substrate ◽  
Laser Alloying ◽  
Micro Hardness ◽  
Transmission Electron ◽  
Intensity Transfer ◽  
Scanning Electron

Effect of the tempering on the microstructures and tribological properties of the laser alloying coatings is investigated. Laser alloying of the T - Co 50/ TiC mixed powders on a 45 steel substrate can form a hard composite coating, which increased the micro-hardness and wear resistance of the substrate greatly. Such laser alloying coating was investigated by means of a scanning electron microscope (SEM) and a transmission electron microscope (TEM). Experimental results indicate that the tempering is able to remove the accumulation of the residual stress in a certain extent, improving the plastic and toughness properties of such coating; moreover, tempering also improves greatly the formation mechanism, making the coating have enough ability of the intensity transfer, which is beneficial in preventing the crack propagation of the interface in such coating, leading to an improvement of the wear resistance.

PHASE CONSTITUENTS AND MICROSTRUCTURE OF Ti3Al/Fe3Al + TiN/TiB2 COMPOSITE COATING ON TITANIUM ALLOY

2011 ◽  
Vol 18 (03n04) ◽  
pp. 103-108 ◽  
Author(s):  
JIANING LI ◽  
CHUANZHONG CHEN ◽  
CUIFANG ZHANG
Keyword(s):  
Wear Resistance ◽  
Titanium Alloy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Composite Coating ◽  
Laser Cladding ◽  
X Ray Diffraction ◽  
X Ray ◽  
Laser Cladding Process ◽  
Scanning Electron

Laser cladding of the Fe3Al + B4C/TiN + Al2O3 pre-placed powders on the Ti-6Al-4V alloy can form the Ti3Al/Fe3Al + TiN/TiB2 composite coating, which improved the wear resistance of the Ti-6Al-4V alloy surface. In this study, the Ti3Al/Fe3Al + TiN/TiB2 composite coating has been researched by means of X-ray diffraction and scanning electron microscope. It was found that during the laser cladding process, Al2O3 can react with TiB2 , leading to the formations of Ti3Al and B . This principle can be used to improve the Fe3Al + B4C/TiN laser-cladded coating on the Ti-6Al-4V alloy. Furthermore, during the cladding process, C consumed the oxygen in Fe3Al + B4C /TiN + Al2O3 molten pool, which retarded the productions of the redundant metal oxides.

Deposition of TiC on γ-TiAl Alloys by Directly Applying Voltages

2005 ◽  
Vol 107 ◽  
pp. 145-150 ◽  
Author(s):  
Chatdanai Boonruang ◽  
Titipun Thongtem ◽  
Michael J. McNallan ◽  
Somsorn Singkarat ◽  
Somchai Thongtem
Keyword(s):  
Wear Resistance ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Electrical Power ◽  
Knoop Hardness ◽  
Rutherford Backscattering ◽  
Energy Dispersive ◽  
Tial Alloys ◽  
X Ray ◽  
Scanning Electron

Two γ-TiAl alloys, Ti-47Al-2Nb-2Cr (MJ12) and Ti-47Al-2Nb-2Mn-0.8TiB2 (MJ47), were pressed in C powder to form rods and carburized by directly applying electrical power through them at 274.3 ± 26.4 W, 80 A for MJ12 and at 293.4 ± 16.8 W, 80 A for MJ47 in Ar atmosphere. The alloys were analysed using an x-ray diffractometer (XRD), a scanning electron microscope (SEM) equipped with an energy dispersive x-ray (EDX) analyser and a Rutherford backscattering spectrometer (RBS) incorporated with NUSDAN solfware. Knoop hardness and wear resistance were improved and found to be in accord with the analytical results.

Effect of Incident Angle on Laser Transformation Hardening Layer Microstructure and Properties

2010 ◽  
Vol 148-149 ◽  
pp. 606-610
Author(s):  
Xing Wu Qiu
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Co2 Laser ◽  
Incident Angle ◽  
X Ray ◽  
Laser Transformation Hardening ◽  
40Cr Steel ◽  
Scanning Electron

Laser transformation hardening was carried out by HL-1500 CO2 laser on 40Cr steel. The macroscopic and properties were analysised by scanning electron microscope, X-ray diffractometer, microhardness meter and potentiostat. The result indicated that, the hardening layer is mainly constitute by Fe-Cr, C0.09Fe1.91, Fe2Si. After laser transformation hardening the hardness enhanced greatly, the maximum of hardness appears in the subsurface, which value is as about four times as that of the substrate, both wear resistance and corrosion resistance are improved. With the increase of the laser incident angle, microstructure’s inhomogeneity becomes larger, properties become decreased.

Influence of Ultrasonic Peening on Wear Resistance of U70 Rails

2010 ◽  
Vol 97-101 ◽  
pp. 1471-1474 ◽  
Author(s):  
Zhao Xia Chen ◽  
Bo Lin He
Keyword(s):  
Plastic Deformation ◽  
Wear Resistance ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Plastic Deformation Zone ◽  
Wear Property ◽  
Ultrasonic Peening ◽  
The Matrix ◽  
The One ◽  
Scanning Electron

The surface of U70 rails was treated by ultrasonic peening method. Keeping the electric current 1.5 A, the amplitude 24 µm and the frequency 10000 HZ during the treatment, the peening duration was 10 min, 20 min, 40 min and 60 min respectively. The wear property, wear appearance, and structural appearance of specimens have been studied by M-2000 wear tester and 6360LA scanning electron microscope. Results show that ultrasonic peening treatment can significantly improve the wear resistance of U70 rails, and the longer the peening duration, the stronger the wear resistance. The wear mass loss of the specimen with 60 min treatment is only 27 % of the one untreated. The reason is that ultrasonic peening can form plastic deformation zones. The depth of plastic deformation zones increases with the peening duration. The depth of plastic deformation zones of the specimen with 60 min treatment is nearly 100 µm. Longer peening duration means severer plastic deformation. In the plastic deformation zone, ferrite is refined to smaller grains so that the matrix is strengthened.

MICROSTRUCTURES AND WEAR RESISTANCE OF THE ARGON ARC CLAD NICKEL-BASED COMPOSITES ON TITANIUM ALLOY

2019 ◽  
Vol 26 (08) ◽  
pp. 1950047
Author(s):  
JIANING LI ◽  
MOLIN SU ◽  
LIWEI ZHANG
Keyword(s):  
Wear Resistance ◽  
Titanium Alloy ◽  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Nanoscale Particles ◽  
Amorphous Phases ◽  
Transmission Electron ◽  
Titanium Alloy Substrate ◽  
Scanning Electron

The composites were obtained by the argon-arc cladding (AAC) of the Deloro22-Si3N4-Fe pre-placed powders on a TA1 titanium alloy substrate, which improved the wear resistance of the substrate. Such composites were investigated by means of the scanning electron microscope (SEM), the microscope and the high resolution transmission electron microscope (HRTEM). The results indicated that the amorphous phases were produced in such AAC composites, increasing the wear resistance. With addition of Y2O3, lots of the micro/nanoscale particles were formed, which further improved the wear resistance of such AAC composites.

Effects of MgO Addition Level on Microstructure and Wear Resistance of Ni-WC Vacuum Fusion Sintering Coating

2010 ◽  
Vol 154-155 ◽  
pp. 942-945 ◽  
Author(s):  
Ya Nan Wang ◽  
Li Ying Han ◽  
Xiao Da Wang
Keyword(s):  
Wear Resistance ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Base Metal ◽  
Energy Dispersive Spectrometer ◽  
Longitudinal Section ◽  
Surface Microstructure ◽  
Compound Coatings ◽  
Addition Level ◽  
Scanning Electron

Ni-WC-MgO compound coatings were made by way of Vacuum Fusion Sintering (VFS). Effects of MgO addition level on the microstructures of coating surface and longitudinal section, element diffusion in fusion sintering area and wear resistance were analyzed through scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). The results showed as the following: MgO addition made coating and matrix combined closely; there existed obvious transition region. When the addition level of MgO was 0.5%, the coating had the fewest defects and best combination. Ni, Cr, W, C and other elements in the coating diffused to the direction of the base metal while Fe in the base metal diffused to the coating, during which the diffusion of Fe and Ni was most obvious at the junction. Therefore, when the addition level of MgO was 0.5%, the surface microstructure of the coating was the densest and finest, and the wear resistance of the coating was the best.

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