Nano-Scale Fatigue Wear of Carbon Nitride Coatings: Part II—Wear Mechanisms

2003 ◽  
Vol 125 (2) ◽  
pp. 437-444 ◽  
Author(s):  
Dong F. Wang ◽  
Koji Kato
Keyword(s):  
Wear Mechanisms ◽  
Carbon Nitride ◽  
Low Cycle Fatigue ◽  
Surface Flow ◽  
Theoretical Expression ◽  
Asperity Contact ◽  
Wear Particles ◽  
Critical Number ◽  
Fatigue Wear ◽  
Nitride Coatings

This is the second part of two companion papers, the first of which reported the empirical data on wear properties in carbon nitride coatings by a spherical diamond counter-face in repeated sliding contacts through in situ examination, with an emphasis on the effect of friction cycles and normal load. The second part will concentrate on wear mechanisms for the transition from “No observable wear particles” to “Wear particle generation.” The relationship between the critical number of friction cycles, Nc, and the representative plastic strain, Δεp, at asperity contact region was confirmed to follow the Manson-Coffin equation with two empirical constants, β and C. The observed generation of wear particles in carbon nitride coatings is therefore concluded to be a low cycle fatigue wear by surface flow and surface delamination in the ploughing mode. For further predicting lifespan, a simplified theoretical expression, combining the Manson-Coffin equation with the analytical solution of a proposed elastic perfectly-plastic indentation model, gives the relation between the critical number of friction cycles, Nc, and the coating thickness h, with respect to the contact pressure P, and the radius R of the asperity on the tip of the diamond pin.

An Analytical Model of Mechanistic Wear of Polymers

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Sandip Panda ◽  
Mihir Sarangi ◽  
S. K. Roy Chowdhury
Keyword(s):  
Abrasive Wear ◽  
Wear Mechanisms ◽  
Low Cycle Fatigue ◽  
Polymer Surface ◽  
Hard Metal ◽  
Polished Surface ◽  
Asperity Contact ◽  
Sliding Interfaces ◽  
Polymer Metal ◽  
Adhesive Interactions

This paper proposes a wear model for polymers based on so-called mechanistic processes comprising both low cycle fatigue and abrasive wear mechanisms, which are prominent in polymer–metal sliding interfaces. Repeated elastic contact causes localized fatigue, whereas abrasive part is an anticipatory outcome of plastic contacts by hard metal asperities on to soft polymer surface. Further, presuming adhesive interactions in elastic–plastic contacts, asperity contact theories with necessary modifications were analyzed to assess load and separation for their subsequent use in elementary wear correlations. Both Gaussian and Weibull distributions of asperity heights were considered to include statistics of surface microgeometry. Finally, volumetric wear was written in terms of roughness parameters, material properties, and sliding distance. Validation was conducted extensively, and reliability of the formulation was achieved to a large extent. Experimental part of this work included several pin-on-disk tests using polyether ether ketone (PEEK) pins and 316L stainless steel disks. Disks with different roughness characteristics generated by polishing, turning, and milling were tested. Experimental results agreed well with predictions for the polished surface and with some deviations for other two surfaces. Further, fatigue to abrasive wear ratio was identified as an analytical tool to predict prevailing wear mechanism for polymer-metal tribo-systems. After examining the considered cases, it was both interesting and physically intuitive to observe a complete changeover in wear mechanisms following simply an alteration of roughness characteristics.

Nano-Scale Fatigue Wear of Carbon Nitride Coatings: Part I—Wear Properties

2003 ◽  
Vol 125 (2) ◽  
pp. 430-436 ◽  
Author(s):  
Dong F. Wang ◽  
Koji Kato
Keyword(s):  
Carbon Nitride ◽  
Wear Track ◽  
Wear Particles ◽  
Nitride Coating ◽  
Wear Properties ◽  
Mode Change ◽  
Nitride Coatings ◽  
Wear Mode ◽  
In Situ Examination

This paper, the first of two companion papers, reports empirical data on wear properties in carbon nitride coatings by a spherical diamond counter-face in repeated sliding contacts through in situ examination and post-sliding observation, with an emphasis on the effects of friction cycles and normal load. In the repeated sliding, a specific wear amount of about 10−9mm3/Nm was observed on the wear track of the carbon nitride coating when no wear particles were detected. On the other hand, a specific wear amount of about 10−6mm3/Nm was observed on the wear track of the carbon nitride coating, where wear particles were generated after a certain number of friction cycles. Wear rate change corresponds to a wear mode change. From in situ examination, the critical number of friction cycles, Nc, for wear particle generation is proven to be related to a wear mode change.

The Influence of Temperature on Failure Development in Steels Under Transition to Seizure

1996 ◽  
Vol 118 (3) ◽  
pp. 527-531 ◽  
Author(s):  
L. Rapoport
Keyword(s):  
Wear Mechanisms ◽  
Skin Effect ◽  
Oxide Films ◽  
Disk Surface ◽  
Wear Particles ◽  
Temperature Model ◽  
Mechanical Instability ◽  
Infinite Body ◽  
Temperature Instability ◽  
Adhesion Interaction

Seizure phenomena in pin-on-disk tests have been studied for “soft” and “hard” steel specimens. Differences in competing and dominant wear mechanisms under steady state friction have been preserved for “soft” and “hard” specimens in the region of transition to seizure or galling. Severe wear was observed for “soft” specimens under all loads tested, while adhesion and splitting off of wear particle conglomerates (microseizure) were identified for “hard” specimens. The contact temperature, calculated in accordance with the temperature model of plastically deformed contact spots (Kuhlmann-Wilsdorf), has appeared to be low for “soft” specimens and not sufficient for adhesion interaction. The effect of oxide films on the friction of “hard” specimens has been estimated in accordance with the temperature model for a coated semi-infinite body (Tian and Kennedy). The insulated oxide films on the surface of “hard” specimens create the “skin effect” and lead, therefore, to raising the temperature up to the temperature of adhesion interaction. Temperature instability of hard surfaces has been demonstrated to result from the “skin effect” and from a disturbance in equilibrium of formation and failure of oxide films. It has been shown that for “soft” specimens the prime cause of transition to seizure was the mechanical interlocking between the wear particles and the soft disk surface combined with mechanical instability, while for “hard” specimens the cause was temperature instability. A more realistic temperature model of the contact has been considered, which takes into account some competing wear mechanisms (oxidational wear, ploughing, delamination) and the effect of wear particles.

Influence of Particle Size of Wheat Powder on Roller Wear Properties

2015 ◽  
Vol 1120-1121 ◽  
pp. 1316-1319
Author(s):  
Liang Peng Jiang ◽  
Ke Ping Zhang ◽  
Jun Min Ma
Keyword(s):  
Weight Loss ◽  
Particle Size ◽  
Wear Behavior ◽  
Low Cycle Fatigue ◽  
Milling Process ◽  
Wear Properties ◽  
Fatigue Wear ◽  
Wear Performance ◽  
Powder Particles ◽  
Three Body

Wheat milling process involves multiple grinding procedures, the wheat powder particles size in different grinding procedure are difference. In order to study the influence of particle size of wheat powder on roller wear performance in different grinding procedure, abrasion experiments were carried out by MLS-225 three-body abrasive wear tester, while different sizes were chosen as abrasive, alloy white iron which frequently used as roller metal materials was chosen as wear sample, wear weight loss and surface microstructure were chosen as the main evaluation indicators. The results showed that the weight loss of samples were showed a linear relationship with wheat the size of wheat powder. The main wear behavior was mainly mechanical polishing while particle sizes was smaller one. For the larger size, wear was made by multiple plastic deformation and low cycle fatigue wear mechanism.

Corrosive-wear behavior of LSP/MAO treated magnesium alloys in physiological environment with three pH values

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yongshui Shen ◽  
Tongjin Sun ◽  
Tao Zhu ◽  
Ying Xiong
Keyword(s):  
Abrasive Wear ◽  
Wear Mechanisms ◽  
Adhesive Wear ◽  
Laser Shock ◽  
Corrosion Wear ◽  
Fatigue Wear ◽  
Wear Rates ◽  
Ph Values ◽  
Wear And Corrosion ◽  
Micro Arc Oxidation

Abstract A laser shock peening (LSP) layer, a micro-arc oxidation (MAO) coating, and an LSP/MAO composite coating were fabricated on the surface of AZ80 magnesium alloy by laser shock and micro-arc oxidation process. The ball-disc grinding method was used to perform wear test on the three treated specimens in simulated body fluids (SBF) with pH values of 4, 7.4 and 9. The morphology and element content of worn surface were investigated by scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). The results indicated that the wear rates of the three treated specimens in three pH environment in numerical order were pH 4 > pH 7.4 > pH 9, respectively. The wear rates of the three treated specimens in the same pH environment were arranged in the order of MAO > LSP > LSP/MAO, respectively. The main wear mechanisms of the LSP specimen in pH 4 environment were fatigue wear and corrosion wear, while it were corrosion wear and adhesive wear in pH 7.4 and pH 9 environments. Abrasive wear, fatigue wear and corrosion wear were the main wear mechanisms of the MAO specimen in pH 4 environment, while abrasive wear, adhesive wear and corrosion wear were the main wear mechanisms of that in pH 7.4 and pH 9 environments. The corrosion wear resistance of the LSP/MAO specimen in SBF solution with three pH values was improved due to the synergism of LSP fine crystal layer and MAO coating.

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