Electroplated Overlays for Crankshaft Bearings

1993 ◽  
Vol 115 (4) ◽  
pp. 706-710 ◽  
Author(s):  
D. R. Eastham
Keyword(s):  
Fatigue Strength ◽  
Selection Criteria ◽  
Diffusion Rate ◽  
Diffusion Control ◽  
Wear Properties ◽  
Wear Rates ◽  
Lead Alloys ◽  
Copper Interlayer ◽  
Thin Nickel ◽  
Composite Bearing

Overlays of either lead-indium or lead-tin-copper are electroplated onto both lead-bronze and aluminum alloy crankshaft bearings to improve seizure resistance and conformability during the initial running-in period. In addition, both the corrosion resistance, particularly of lead-bronze, and the effective fatigue strength of the composite bearing are improved by this layer. The life of the overlay is largely dependent upon the diffusion rate of the low melting point species to the substrate. Thus, migration of either the indium or the tin will determine both the corrosion and wear rates of the overlay. Owing to the processing requirements, aluminum bearings require a nickel or copper interlayer prior to final overlaying with either of the lead alloys. For diffusion control reasons, when depositing lead-tin-copper onto lead-bronze it is usual to have a thin nickel dam to retard the formation of copper-tin intermetallics, which under given conditions may reduce the overall strength and adhesion; lead-indium does not require such a dam on lead-bronze. The principal differences between the two overlays lie in their respective fatigue and wear properties. Thus, lead-indium has a higher fatigue strength but lower wear resistance than lead-tin-copper. This paper compares these two major overlays and considers the selection criteria for the overlay employed.

Influence of Multiwall Carbon Nanotube on mechanical and wear properties of Copper – Iron composite

2020 ◽  
Vol 17 (1) ◽  
pp. 7570-7576 ◽  
Author(s):  
H. Sh. Hammood ◽  
S. S. Irhayyim ◽  
A. Y. Awad ◽  
H. A. Abdulhadi
Keyword(s):  
Carbon Nanotubes ◽  
Volume Fraction ◽  
Hybrid Composites ◽  
Hydraulic Press ◽  
Dry Sliding Wear ◽  
Multiwall Carbon Nanotube ◽  
Wear Properties ◽  
Sem Images ◽  
Wear Rates ◽  
Multiwall Carbon

Multiwall Carbon nanotubes (MWCNTs) are frequently attractive due to their novel physical and chemical characteristics, as well as their larger aspect ratio and higher conductivity. Therefore, MWCNTs can allow tremendous possibilities for the improvement of the necessarily unique composite materials system. The present work deals with the fabrication of Cu-Fe/CNTs hybrid composites manufactured by powder metallurgy techniques. Copper powder with 10 vol. % of iron powder and different volume fractions of Multi-Wall Carbon Nanotubes (MWCNTs) were mixed to get hybrid composites. The hybrid composites were fabricated by adding 0.3, 0.6, 0.9, and 1.2 vol.% of MWCNTs to Cu- 10% Fe mixture using a mechanical mixer. The samples were compressed under a load of 700 MPa using a hydraulic press to compact the samples. Sintering was done at 900°C for 2 h at 5ºC/min heating rate. The microscopic structure was studied using a Scanning Electron Microscope (SEM). The effect of CNTs on the mechanical and wear properties, such as micro-hardness, dry sliding wear, density, and porosity were studied in detail. The wear tests were carried out at a fixed time of 20 minutes while the applied loads were varied (5, 10, 15, and 20 N). SEM images revealed that CNTs were uniformly distributed with relative agglomeration within the Cu/Fe matrix. The results showed that the hardness, density, and wear rates decreased while the percentage of porosity increased with increasing the CNT volume fraction. Furthermore, the wear rate for all the CNTs contents increased with the applied load.

Effect of CeO2 addition on microstructure and tribological characteristics of laser cladded Cu10Al–MoS2 coating under oil lubrication

2021 ◽  
pp. 146442072110309
Author(s):  
Shao Lifan ◽  
Ge Yuan ◽  
Kong Dejun
Keyword(s):  
Abrasive Wear ◽  
Wear Mechanism ◽  
Mass Fraction ◽  
Friction Reduction ◽  
Depth Of Field ◽  
Oil Lubrication ◽  
Wear Properties ◽  
Fatigue Wear ◽  
Wear Rates ◽  
Mass Fractions

In order to improve the friction and wear properties of Cu10Al–MoS2 coating, the addition of CeO2 is one of the present research hot spots. In this work, Cu10Al–MoS2 coatings with different CeO2 mass fractions were successfully fabricated on Q235 steel using a laser cladding. The microstructure and phase compositions of obtained coatings were analyzed using an ultra-depth of field microscope and X-ray diffraction, respectively. The friction-wear test was carried out under oil lubrication using a ball-on-disk wear tester, and the effects of CeO2 mass fraction on the microstructure, hardness, and friction-wear properties were studied, and the wear mechanism was also discussed. The results show that the laser cladded Cu10Al–MoS2 coatings with the different CeO2 mass fractions were mainly composed of Cu9Al4, Cu, AlFe3, Ni, MoS2, and CeO2 phases. The Vickers-hardness (HV) of Cu10Al–8MoS2–3CeO2, Cu10Al–8MoS2–6CeO2, and Cu10Al–8MoS2–9CeO2 coatings was 418, 445, and 457 HV0.3, respectively, which indicates an increase in hardness with the increase of CeO2 mass fraction. The average coefficients of friction (COF) and wear rates decrease with the increase of CeO2 mass fraction, presenting the outstanding friction reduction and wear resistance performances. The wear mechanism of Cu10Al–MoS2 coatings is changed from abrasive wear with slight fatigue wear to abrasive wear with the increase of CeO2 mass fraction.

Wear Properties of Y-TZP Ceramics Dispersed with Second Phase Particles

2008 ◽  
Vol 368-372 ◽  
pp. 744-747
Author(s):  
Xiao Ping Liang ◽  
Shao Bo Xin ◽  
Xiao Hui Wang ◽  
Zheng Fang Yang
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Mass Fraction ◽  
Normal Load ◽  
Roller Bearing ◽  
Second Phase ◽  
Wear Properties ◽  
Wear Rates ◽  
Second Phase Particles ◽  
Better Than

The wear properties of ADZ (alumina dispersed in Y-TZP) and MDZ (mullite dispersed in Y-TZP) were investigated by using a ring-on-block tribometer. The results showed that for Y-TZP ceramic, the addition of alumina phase (with 10-20% in mass fraction) leads to an improved wear resistance. With the increase of the normal load, the wear rates of ADZ ceramics increase. Under low and medium normal load (100N and 300N), the wear resistance is controlled by the hardness of ceramics, and under high normal load (500N) the fracture toughness is obviously contributed to the wear resistance of the ceramics. For MDZ ceramic, the wear resistance of 15MDZ (15wt% mullite dispersed in Y-TZP) is better than that of 20 MDZ (20wt% mullite) under the normal load from 100 N to 500 N. The mechanical properties of 15MDZ are worse than that of Y-TZP ceramic, but the wear resistance is enhanced due to the action of “needle roller bearing” of the fractured rod-like mullite particles.

Evaluation of Total Ankle Arthroplasty Using Highly Crosslinked Ultrahigh-Molecular-Weight Polyethylene Subjected to Physiological Loading

2019 ◽  
Vol 40 (8) ◽  
pp. 880-887 ◽  
Author(s):  
Jeffrey E. Bischoff ◽  
Mehul A. Dharia ◽  
Justin S. Hertzler ◽  
Oliver N. Schipper
Keyword(s):  
Fatigue Strength ◽  
Fatigue Testing ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Fatigue Loading ◽  
Strength Properties ◽  
Total Ankle Arthroplasty ◽  
Wear Properties ◽  
Ankle Arthroplasty ◽  
Walking Gait

Background: Highly crosslinked polyethylene (HXLPE) was developed for its superior wear properties in comparison to conventional polyethylene (CPE). Concern over fatigue resistance has prevented widespread adoption of HXLPE for use in total ankle arthroplasty (TAA). The aim of this study was to determine whether HXLPE has sufficient fatigue strength for total ankle arthroplasty under simulated physiologically relevant motion profiles and loading in the ankle. Methods: Physiologic load and motion profiles representative of walking gait were incorporated into a computational model of a semiconstrained, fixed-bearing TAA to determine the loading state with highest stresses in the HXLPE bearing. Subsequent fatigue testing to 10 million cycles (Mc) at 5600 N was performed to assess bearing strength. Results: Peak stresses in the bearing were predicted at peak axial load and peak dorsiflexion during gait, occurring near heel off. All samples withstood 10 Mc of fatigue loading at that orientation without polyethylene bearing fracture. Conclusion: HXLPE had sufficient fatigue strength to withstand 10 Mc of loading at more than 5 times body weight at the point of peak stresses during simulated gait in total ankle arthroplasty. Clinical Relevance: HXLPE may be mechanically strong enough to withstand the in vivo demands of the ankle. Improvements in wear afforded by HXLPE can be obtained without compromising sufficient polyethylene strength properties in total ankle arthroplasty.

The Effect of Tribofilm Formation and Humidity on the Friction and Wear Properties of Ceramic Materials

1992 ◽  
Vol 114 (1) ◽  
pp. 131-140 ◽  
Author(s):  
K. Komvopoulos ◽  
H. Li
Keyword(s):  
Steady State ◽  
Wear Debris ◽  
Friction And Wear ◽  
Ceramic Materials ◽  
Composition Analysis ◽  
Wear Properties ◽  
Qualitative Comparison ◽  
Wear Rates ◽  
Subsurface Material ◽  
Friction And Wear Properties

The processes of tribofilm formation and disruption and the predominant tribo-mechanisms of unlubricated ceramic materials were investigated experimentally. Sliding experiments in humidity controlled atmospheres revealed that the formation of interfacial tribofilms significantly affects the steady-state friction and wear properties of ceramics. Scanning electron microscopy and various composition analysis techniques demonstrated that although tribochemical reactions might occur, the principal mechanisms of tribofilm formation were the generation, agglomeration, and compaction of fine wear debris produced from both sliding surfaces. The tribofilms exhibited different tribological characteristics, depending on their elemental compositions and the humidity. For all the ceramic pairs tested, the steady-state coefficients of friction decreased with relative humidity. In contrast to the conventional fracture toughness approach, surface profilometry and microscopy studies showed that the highest wear rates were encountered with the toughest ceramic. Plowing grooves parallel to the direction of sliding, fine wear debris of round and cylindrical shapes, microcracking, and localized delamination of the tribofilms were identified. Microscopic observations suggested that damage of the subsurface material adjacent to the interface of the tribofilms was immeasurable. Qualitative comparison of the topographical features of worn surfaces indicated that, depending on the humidity and the type of ceramic, microplasticity, microfracture, and delamination of the tribofilms were the prevailing steady-state tribomechanisms.

Tribological Behaviors of Polymer Based Composites under Alkaline Conditions

2012 ◽  
Vol 510 ◽  
pp. 563-568
Author(s):  
Yan Ji Zhu ◽  
Hui Juan Qian ◽  
Gui Ying Wang ◽  
Huai Yuan Wang
Keyword(s):  
Wear Resistance ◽  
Frame Structure ◽  
Alkaline Condition ◽  
Wear Properties ◽  
Friction Coefficients ◽  
Wear Rates ◽  
Transfer Films ◽  
Peek Composite ◽  
Alkaline Conditions ◽  
Ptfe Composites

In this paper, polyetheretherketone (PEEK) and polytetrafluoroethylene (PTFE) based composites reinforced with various amounts of potassium titanate whiskers (PTWs) or short carbon fibers (CF) were designed and fabricated respectively. The friction and wear properties of PEEK and PTFE based composites sliding under rigorous alkaline were comparatively investigated. Also, the morphologies of the worn and counterpart surfaces were studied by scanning electron microscopy (SEM). Because of the stable tunnel crystal structure and frame structure micro-reinforcement capacity, PTWs show outstanding performances in increasing the wear resistance and reducing the friction coefficients of both PEEK and PTFE based composites under alkaline. However, CF leads to the degradation of wear resistance and the increase of friction coefficient of PEEK based composites under alkaline. Furrows and abrasive wear were the main mechanisms for CF/PTFE/PEEK and CF/PTFE composites sliding in alkali. The results show that PTW/PTFE composites exhibit higher wear resistance under lower load, while PTW/PTFE/PEEK composite is more suitable for higher load under alkaline condition. Owing to the primary cooling and boundary lubricating effects of alkali, the wear rates and friction coefficients of PTFE composites and PTW/PTFE/PEEK composites decreased obviously, though the transfer films onto the counterpart steel surface were hindered considerably.

Effect of hybrid surface treatment composed of nitriding and DLC coating on friction-wear properties and fatigue strength of alloy steel

2016 ◽  
Vol 661 ◽  
pp. 105-114 ◽  
Author(s):  
Tatsuro Morita ◽  
Kenta Inoue ◽  
Xiaoteng Ding ◽  
Yoshitaka Usui ◽  
Masaru Ikenaga
Keyword(s):  
Fatigue Strength ◽  
Surface Treatment ◽  
Alloy Steel ◽  
Wear Properties ◽  
Dlc Coating

Solvent-Selection Criteria Based on Diffusion Rate and Mixing Quality for Steam/Solvent Applications in Heavy-Oil and Bitumen Recovery

2016 ◽  
Vol 19 (04) ◽  
pp. 620-632 ◽  
Author(s):  
A.. Marciales ◽  
T.. Babadagli
Keyword(s):  
Heavy Oil ◽  
Selection Criteria ◽  
Diffusion Rate ◽  
Asphaltene Precipitation ◽  
Solvent Selection ◽  
Solvent Injection ◽  
Mixing Quality ◽  
Bitumen Recovery ◽  
Static Conditions

Summary Heavy-oil and bitumen recovery requires high recovery factors to offset the extreme high cost of investments and operations. Attention has been given to solvent injection for this purpose, and it has been observed that high recoveries are achievable when it is combined with steam injection. Heavier (“liquid”) solvents (liquid at ambient conditions) are especially becoming more popular because of availability and transportation. High oil prices will allow the application of this kind of technique if a proper design is made to retrieve the injected solvent efficiently. “Liquid” solvents are advantageous because they yield a better-quality mixing (especially with very heavy oils and bitumen) but a lower diffusion rate than lighter solvents such as propane or butane. Despite this understanding, there still is not a clear screening criterion for solvent selection to mitigate both diffusion rate and the quality of the mixture. In this study, two main solvent-selection-criteria parameters—diffusion rate and mixing quality—were considered to evaluate solvent-injection efficiency at different temperatures. An optical method under static conditions and image-processing techniques were proposed to determine 1D diffusivity of liquid solvent into a wide range of oil samples in a capillary tube. This sampling range varies from 40-cp oil to 250-cp oil, for which digital-image treatment was developed. X-ray computerized tomography (CT) was applied for heavier (and darker) oils (viscosity range of 20,000 cp to 400,000 cp). The diffusion coefficients were then computed through nonlinear curve fitting on the basis of an optimization algorithm to ensure that the obtained values were in agreement with available analytical solutions. Next, viscosity measurements and asphaltene precipitation for the same heavy-oil/solvent mixtures were performed to determine the mixing quality. The ideal solvent types for different oil types were determined by using the results from the diffusion-rate and mixing-quality experiments. The experimental and semianalytical outcome of this research would be useful in the determination of the best solvent type for a given oil and in understanding the key factors that influence the quality of mixtures including viscosity reduction and probable asphaltene precipitation.

Phase transformation effects on the wear properties of alumina gel–polymer matrix nanocomposites

2001 ◽  
Vol 16 (6) ◽  
pp. 1680-1685 ◽  
Author(s):  
Jiazhong Luo ◽  
John Lannutti ◽  
Robert Seghi
Keyword(s):  
Phase Transformation ◽  
Polymer Matrix ◽  
Polymer Matrix Composites ◽  
Growth Patterns ◽  
Matrix Composites ◽  
Wear Properties ◽  
Wear Rates ◽  
Alumina Gel ◽  
Matrix Nanocomposites ◽  
Polymer Matrix Nanocomposites

A phase transformation in an alumina gel provided an elegant means of isolating the effect of filler properties on the wear resistance of particle-reinforced thermosetting polymer–matrix composites. This transformation was useful because it takes place without significantly altering filler porosity. This produced a wear surface apparently reflecting the vermicular growth patterns in the γ-alumina in the δ-aluminum monohydrate matrix. Nucleation of γ-alumina in the gel matrix produced wear rates comparable to commercial composites.

Tribologische Charakterisierung von Polymerfasern unter Trockenreibung, Mischreibung und Hydrodynamik mittels einer optimierten Pin-on-Disc-Prüfmethode

2021 ◽  
Vol 68 (3-4) ◽  
Author(s):  
Regine Schmitz ◽  
Frank Haupert ◽  
Justus Rüthing ◽  
Michael Sigrüner ◽  
Nicole Strübbe
Keyword(s):  
Fiber Material ◽  
Test Method ◽  
Polymer Fibers ◽  
Test Sequence ◽  
Material Surface ◽  
Wear Properties ◽  
Line Load ◽  
Wear Rates ◽  
Single Fibers ◽  
Pin On Disc

Based on the conventional pin-on-disc test method, a tribology test rig was adapted and optimized regarding its ability to characterize polymer fibers. The method is explained and first applications in the field of tribological characterization of single fibers are presented. The test sequence to investigate the polymer fibers (diameters of only a few 100 µm) is generated in such a way that data can be recorded continuously as a function of time in the wear range from a few 10 µm to several 100 µm even during the first few minutes. The test mode starts by applying line load and dynamically progresses to area load by changing the contact area during the measurement. It is shown that single fibers can be characterized with respect to their friction and wear properties in different tribological systems. The dependence of the wear rates of fiber material, surface roughness of the counter bodies and lubrication rates is presented.

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