scholarly journals Remarks on Wear Transitions Related to Hardness and Size of Abrasive Particles

2021 ◽  
Author(s):  
Giuseppe Pintaude
Keyword(s):  
Abrasive Wear ◽  
Size Effects ◽  
Critical Values ◽  
Abrasive Particles ◽  
Severe Wear ◽  
Wear Rates ◽  
Particle Fragmentation ◽  
Current State ◽  
State Of Art

Abrasive wear is highly dependent on the characteristics and properties of abrasive particles. Their hardness and size can define the severity of abrasion in terms of wear rates. Typically, critical values have been empirically determined to define the transition between mild and severe wear. This review aims to update some of the issues related to these critical values and their relations to abrasive wear. After presenting the current state-of-art, the following items are discussed: a) the scratchability of materials; b) the particle fragmentation associated with size effects; and c) description of abrasion severity.

scholarly journals Endoscopic Spine Surgery: Current State of Art and the Future Perspective

2018 ◽  
Vol 12 (1) ◽  
pp. 1-2 ◽  
Author(s):  
Andrew Seok Min Moon ◽  
Sakthivel Rajan Rajaram Manoharan
Keyword(s):  
Spine Surgery ◽  
Future Perspective ◽  
Endoscopic Spine Surgery ◽  
Current State ◽  
The Future ◽  
State Of Art

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.

Theoretical evaluation of abrasive wear behavior of B4C/ FeCrC coating layer evaluated by a Taguchi approach

2020 ◽  
Vol 62 (7) ◽  
pp. 733-738 ◽  
Author(s):  
A. K. Gür ◽  
T. Yildiz ◽  
B. Icen
Keyword(s):  
Taguchi Method ◽  
Abrasive Wear ◽  
Arc Welding ◽  
Wear Behavior ◽  
Theoretical Evaluation ◽  
Wear Rates ◽  
Abrasive Wear Behavior ◽  
Coating Layers ◽  
Plasma Transferred Arc Welding ◽  
Aisi 430

Abstract In this study, B4C and FeCrC powders were alloyed on the surface of AISI 430 by a fusion process via plasma transferred arc welding. Mixtures of these powders at various amounts were used. The microstructure and wear behavior of the obtained coating layers were investigated. The wear behavior of the coating layers was planned using the Taguchi method. Abrasive wear mass loss results were optimized with the “smaller the better” control characteristic of the Taguchi method, and the results were analyzed graphically. The actual data obtained at the end of the study were formed by using an L16 (4 × 2, 2 × 2) mixed array, and the remaining wear rates were calculated with the help of theoretical formulas in order to obtain theoretical abrasive wear results.

Characterization of the Resistance of Pyrolytic Carbon to Abrasive Wear

1995 ◽  
Vol 18 (12) ◽  
pp. 777-785 ◽  
Author(s):  
E. Vitale ◽  
P. Giusti
Keyword(s):  
Abrasive Wear ◽  
Heart Valves ◽  
Prosthetic Heart Valve ◽  
Wear Testing ◽  
Limiting Factors ◽  
Wear Behaviour ◽  
Biomedical Devices ◽  
Wear Rates ◽  
Biological Compatibility ◽  
Particle Contamination

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.

scholarly journals The Progress in Photoacoustic and Laser Ultrasonic Tomographic Imaging for Biomedicine and Industry: A Review

2018 ◽  
Vol 8 (10) ◽  
pp. 1931 ◽  
Author(s):  
Anton Bychkov ◽  
Varvara Simonova ◽  
Vasily Zarubin ◽  
Elena Cherepetskaya ◽  
Alexander Karabutov
Keyword(s):  
Ultrasonic Imaging ◽  
Tomographic Imaging ◽  
Current Paper ◽  
Laser Ultrasonic ◽  
Biological Objects ◽  
Current State ◽  
State Of Art

The current paper reviews a set of principles and applications of photoacoustic and laser ultrasonic imaging, developed in the Laser Optoacoustic Laboratories of ILIT RAS, NUST MISiS, and ILC MSU. These applications include combined photoacoustic and laser ultrasonic imaging for biological objects, and tomographic laser ultrasonic imaging of solids. Principles, algorithms, resolution of the developed methods, and related problems are discussed. The review is written in context of the current state-of-art of photoacoustic and laser ultrasonic imaging.

scholarly journals CONTINUED FRACTIONS, INTERMEDIATE FRACTIONS AND THEIR RELATION TO THE BEST APPROXIMATIONS

2020 ◽  
Vol 20 (3) ◽  
pp. 545-560
Author(s):  
LUKA MILINKOVIC ◽  
BRANKO MALESEVIC ◽  
BOJAN BANJAC
Keyword(s):  
Continued Fractions ◽  
Continued Fraction ◽  
Rational Approximations ◽  
Best Approximations ◽  
Current State ◽  
The Subject ◽  
State Of Art

The subject of this paper is the current state of art in theory of continued fractions, intermediate fractions and their relation to the best rational approximations of the first and second kind. The paper provides an overview of the some well known and even some new properties of continued fractions, and the various terms associated with them. In addition to intermediate fractions, paper considers the fine intermediate fractions and gave some statements to position these fractions in the continued fraction representation of numbers.

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