Characterization of the Resistance of Pyrolytic Carbon to Abrasive Wear

Si-alloyed pyrolitic carbon (PyC) is currently employed in many biomedical devices, due to its fairly good biological compatibility and non biodegradeability. For prosthetic heart valve applications, required to operate safely for many years, the resistance to abrasive wear is one of the limiting factors which must be accurately evaluated. The present study reports on abrasive wear testing of Ti/PyC and PyC/PyC sliding couples. For both couples it was found that the wear behaviour can be shifted from a low wear regime, characterised by very small wear rates and reduced scatter, to a high wear regime, characterised by high wear rates and high scatter, due to the presence of particle contamination coming from the environment and/or from the specimen polishing process. Actual biomedical devices, particularly heart valves, should not experience the high wear regime, due to the absence of any hard particle contamination source. The wear observed in these items is in fact minimal and may depend on mechanisms other than abrasive wear. In these conditions the experimental evaluation of the wear behaviour should definetely be performed by tests on actual devices.

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Influence of Load and Temperature on Abrasion of Carbidic Cast Steel and Complex Alloyed Hardfacing

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.674.313 ◽

2016 ◽

Vol 674 ◽

pp. 313-318 ◽

Cited By ~ 4

Author(s):

Markus Varga ◽

Anifa Mohamed Faruck Azhaarudeen ◽

Karl Adam ◽

Ewald Badisch

Keyword(s):

Abrasive Wear ◽

Cast Steel ◽

High Stress ◽

Linear Increase ◽

Wear Testing ◽

Wear Behaviour ◽

Complex Alloy ◽

Wear Rates ◽

Carbide Network ◽

Heavy Loads

Steel and cement industries frequently experience from the failure of its core components due to high temperature (HT) operation at heavy loads causing high stress abrasive wear. In this work the effect of load and temperature on the abrasive wear behaviour is investigated for two Fe-based materials (a ferritic cast iron with Cr-carbide network and a carbide-rich complex alloyed hardfacing) in order to select materials for plant specific demands. Thereby the role of the carbide content and its distribution is of interest. A modified ASTM G65 setup was used for HT abrasive wear testing. The applied loads were 10, 45 and 80 N, and temperatures were room temperature (RT), 500 and 700°C. During testing coefficient of friction was measured and abrasive was collected to characterise the wear behaviour (low stress/high stress condition).High stress abrasion was found to be the dominant mechanism at higher loads for all temperatures. A nearly linear increase of wear rate with raising normal loads was found for both the materials. Wear rates at RT were found to be similar for the two alloys, however the complex alloy showed increased wear at HT. The cast steel formed protective mechanically mixed layers (MML) by abrasive embedding at HT. The hardfacing on the other hand showed brittle behaviour, which worsened with temperature. Based on these results it was concluded that very hard carbide-rich hardfacings performed unbeneficial at high stress conditions and MML-forming materials should be preferred for HT operation under these conditions.

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Investigation on Two-Body Abrasive Wear Behavior of Tungsten Carbide Filled Glass Fabric-Epoxy Hybrid Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.123-125.1039 ◽

2010 ◽

Vol 123-125 ◽

pp. 1039-1042 ◽

Cited By ~ 1

Author(s):

S.P. Kumaresh Babu ◽

Anand Chairman ◽

N. Mohan ◽

Siddaramaiah

Keyword(s):

Abrasive Wear ◽

Tungsten Carbide ◽

Large Scale ◽

Hybrid Composites ◽

Wear Behavior ◽

Constant Load ◽

Glass Fabric ◽

Wear Behaviour ◽

Wear Loss ◽

Wear Rates

The effect of tungsten carbide (WC) particulate fillers incorporation on two-body abrasive wear behaviour of glass fabric reinforced-epoxy (GE) composites was investigated and findings are interpreted. The wear behaviour of the composites were performed using pin-on-disc tester at varying abrasive distances viz., 25,50,75 and 100 m at a constant load of 20 N. The experiment was conducted using two different water proof silicon carbide (SiC) abrasive papers and at two different velocity under multi-pass condition. The wear loss of the composites found increasing with increase in abrading distances. A significant reduction in wear loss and specific wear rates were noticed after incorporation of WC filler into GE composite. This result indicates a significant improvement in wear resistance after incorporation of WC filler. The WC loaded systems exhibit less wear of matrix during abrasion which in turn facilitates lower fiber damage, due to the presence of WC particles on the counter surface which act as a transfer layer and effective barrier to prevent large-scale fragmentation. The worn out surface features were examined through scanning electron microscopy (SEM) in order to probe the wear mechanism.

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Evaluation of Abrasive Wear Resistance of Fe-Cr-C Hardfacing Alloys Deposited on Active Components of the Agricultural Components

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1029.188 ◽

2014 ◽

Vol 1029 ◽

pp. 188-193

Author(s):

Ramona Monica Dobra ◽

Nicolae Farbas ◽

Doru Romulus Pascu

Keyword(s):

Abrasive Wear ◽

Low Carbon Steel ◽

Base Material ◽

Surface Characteristics ◽

Wear Testing ◽

Wear Behaviour ◽

Welding Parameters ◽

Low Carbon ◽

Active Components ◽

Abrasive Wear Behaviour

In most of the engineering applications, such as mining, agriculture, metallurgy, the equipments fail due to abrasive wear. Hardfacing is one of the most economical and most widely used methods of improving surface characteristics of engineering equipments (wear, corrosion) without changing the bulk properties of the components.Fe-Cr-C hardfacing alloys are well known for their excellent performances under severe wear conditions. The wear behaviour of hardfacing alloys depends on their chemical composition, on the microstructure obtained after welding, of the welding technology, respectively the welding parameters which strongly influence, for example, the dilution with the base material or formation of precipitated hard phases.The aim of this study was to characterize the microstructure of Fe-Cr-C hardfacing alloys and to investigate their abrasive wear behaviour. The research has been carried out using four types of Fe-Cr-C hardfacing alloys (8 12, 16 and 20 % Cr). The alloys were deposited on the low-carbon steel S355 JR by manual arc welding method. The abrasion wear testing was carried out using the Taber Rotary Abraser Equipment. The microstructure characterization and surface analysis were performed using optical microscopy and HV 10 hardness tests.

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An Investigation of the Thermal Sprayed Molybdenum Coatings Behaviour to Micro-Abrasion Wear

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.841.15 ◽

2016 ◽

Vol 841 ◽

pp. 15-20

Author(s):

Gheorghe Matache ◽

Alexandru Paraschiv ◽

Cristian Puscasu

Keyword(s):

Experimental Data ◽

Wear Rate ◽

Electric Arc ◽

Wear Testing ◽

Wear Behaviour ◽

Small Scale ◽

Wear Rates ◽

Wear Mode ◽

Three Body Abrasion ◽

Three Body

The wear behaviour of thick molybdenum coatings deposited by electric arc thermal spray on steel support was investigated by micro-abrasion, a relatively recent introduced method for small scale wear testing. The wear mechanisms and wear rates without coatings penetration were investigated with respect of time corresponding to primary and secondary wear stages. The micro-abrasion of Mo coatings using SiC abrasive slurry have been discussed and wear scar characteristics were evaluated based on the experimentally results. The worn surfaces of the tested specimen were examined by SEM and the specific wear rate was calculated from experimental data. For the testing durations used it was identified the change from grooving to rolling wear corresponding to the transition of wear mode from two-body to three body-abrasion.

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Abrasive Wear Behaviour of Plasma Sprayed Al2O3 / TiO2 Coatings

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.b7604.129219 ◽

2019 ◽

Vol 9 (2) ◽

pp. 5020-5023

Keyword(s):

Abrasive Wear ◽

Wear Behaviour ◽

High Wear Resistance ◽

Homogeneous Distribution ◽

Premature Failure ◽

Wear Rates ◽

Spray Coatings ◽

Abrasive Wear Behaviour ◽

Plasma Sprayed ◽

Cylinder Bore

Premature failure due to abrasive wear is observed in high powered engine in recent decades, despite of stringent maintenance procedures comparative to older engine. Plasma spray coatings are recurrently used to circumvent the abrasive wear in aerospace, defense and certain automotive applications like piston pump, cylinder bore etc. This work is to identify the most influencing wear parameters namely sliding speed (SS), applied load (AL) and sliding distance (SD) of the composite coated steel. Initially the surface morphology and elemental analysis was carried out to analyze the surface roughness and homogeneous distribution of the composites. Furthermore wear analyzes results indicates that the composite coating has high wear resistance and specific wear rates are ranging from 0.52346 × 10-5 m 3 / N-m to 3.25711× 10-5 m 3 / N-m

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Bi-unicondylar knee prosthesis functional assessment utilizing force-control wear testing

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1243/09544119jeim726 ◽

2009 ◽

Vol 224 (7) ◽

pp. 813-821 ◽

Cited By ~ 8

Author(s):

M Spinelli ◽

S Affatato ◽

M K Harman ◽

J D DesJardins

Keyword(s):

Knee Replacement ◽

Knee Prosthesis ◽

Experimental Simulation ◽

Wear Testing ◽

In Vivo Studies ◽

Wear Behaviour ◽

Unicompartmental Knee Replacement ◽

Wear Rates ◽

Anterior Posterior ◽

Cycling Time

Recent in vivo studies have identified variations in knee prosthesis function depending on prosthesis geometry, kinematic conditions, and the absence/presence of soft-tissue constraints after knee replacement surgery. In particular, unicondylar knee replacements (UKR) are highly sensitive to such variations. However, rigorous descriptions of UKR function through experimental simulation studies, performed under physiological force-controlled conditions, are lacking. The current study evaluated the long-term functional performance of a widely used fixed-bearing unicompartmental knee replacement, mounted in a bi-unicondylar configuration (Bi-UKR), utilizing a force-controlled knee simulator during a simulated (ISO 14243) walking cycle. The wear behaviour, the femoral—tibial kinematics, and the incurred damage scars were analysed. The wear rates for the medial and the lateral compartments were 10.27 ± 1.83 mg/million cycles and 4.49 ± 0.53 mg/million cycles, respectively. Although constant-input force-controlled loading conditions were maintained throughout the simulation, femoral—tibial contact point kinematics decreased by 65 to 68 per cent for average anterior/posterior travel and by 58 to 74 per cent for average medial/lateral travel with increasing cycling time up to 2 million cycles. There were no significant differences in damage area or damage extent between the medial and the lateral compartments. Focal damage scars representing the working region of the femoral component on the articular surface extended over a range of 16—21 mm in the anterior—posterior direction. Kinematics on the shear plane showed slight variations with increasing cycling time, and the platform exhibited medial pivoting over the entire test. These measures provide valuable experimental insight into the effect of the prosthesis design on wear, kinematics, and working area. These functional assessments of Bi-UKR under force-controlled knee joint wear simulation show that accumulated changes in the UKR articular conformity manifested as altered kinematics both for anterior/posterior translations and internal/external rotations.

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Vanadium Additions to a High-Cr White Iron and its Effects on the Abrasive Wear Behavior.

MRS Advances ◽

10.1557/adv.2020.414 ◽

2020 ◽

Vol 5 (59-60) ◽

pp. 3077-3089

Author(s):

Alexeis Sánchez ◽

Arnoldo Bedolla-Jacuinde ◽

Francisco V. Guerra ◽

I. Mejía

Keyword(s):

Heat Treatment ◽

Abrasive Wear ◽

Volume Fraction ◽

Wear Behavior ◽

Wear Behaviour ◽

White Iron ◽

Heat Treated ◽

Bulk Hardness ◽

Abrasive Wear Behavior ◽

Vanadium Carbides

AbstractFrom the present study, vanadium additions up to 6.4% were added to a 14%Cr-3%C white iron, and the effect on the microstructure, hardness and abrasive wear were analysed. The experimental irons were melted in an open induction furnace and cast into sand moulds to obtain bars of 18, 25, and 37 mm thickness. The alloys were characterized by optical and electronic microscopy, and X-ray diffraction. Bulk hardness was measured in the as-cast conditions and after a destabilization heat treatment at 900°C for 45 min. Abrasive wear resistance tests were undertaken for the different irons according to the ASTM G65 standard in both as-cast and heat-treated conditions under a load of 60 N for 1500 m. The results show that, vanadium additions caused a decrease in the carbon content in the alloy and that some carbon is also consumed by forming primary vanadium carbides; thus, decreasing the eutectic M7C3 carbide volume fraction (CVF) from 30% for the base iron to 20% for the iron with 6.4%V;but overall CVF content (M7C3 + VC) is constant at 30%. Wear behaviour was better for the heat-treated alloys and mainly for the 6.4%V iron. Such a behaviour is discussed in terms of the CVF, the amount of vanadium carbides, the amount of martensite/austenite in matrix and the amount of secondary carbides precipitated during the destabilization heat treatment.

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