The dependence of the transition from severe to mild wear on load and surface roughness when the oxide particles are supplied before sliding

Wear ◽  
1990 ◽  
Vol 139 (2) ◽  
pp. 319-333 ◽  
Author(s):  
A. Iwabuchi ◽  
H. Kubosawa ◽  
K. Hori
Keyword(s):  
Surface Roughness ◽  
Mild Wear ◽  
Oxide Particles

Particle detachment due to wheel rotation

2020 ◽  
pp. 1420326X2093516
Author(s):  
Jinwei Song ◽  
Hua Qian ◽  
Xiaohong Zheng
Keyword(s):  
Surface Roughness ◽  
Silicon Dioxide ◽  
Adhesion Force ◽  
Aluminium Oxide ◽  
Theoretical Models ◽  
Wheel Speed ◽  
Spherical Particles ◽  
Wheel Surface ◽  
Particle Detachment ◽  
Oxide Particles

Particle detachment induced by a rotating wheel was investigated theoretically and experimentally. The developed theoretical models were used to reveal how the particle detaches from a wheel surface to the surrounding air. The corresponding experiments were carried out to validate proposed models. Two groups of spherical particles were considered, i.e. silicon dioxide and aluminium oxide particles. Different forces and force moments acting on individual particles were analysed. The criteria for the rolling detachment of particles were considered. The detachment diameters under various conditions were calculated. The results show that the particle detachment was dominated by the removal and resistant forces acting on particles, including the gravity force, adhesion force, hydrodynamic force and centrifugal force. Different relevant parameters can affect particle detachment through these forces, including surface roughness, wheel speed, particle size and properties. A higher wheel speed, larger particle sizes and higher wheel surface roughness were shown to have a conducive influence on particle detachment. The resistant and removal force moments could be affected by the particle properties at the same time; therefore, the detachment diameters of the aluminium oxide particles are similar to those of silicon dioxide. This study can contribute towards the estimation of particle emissions from vehicles.

Oxidation Behaviors of Inconel 740H in Air and Dynamic Steam

2016 ◽  
Vol 35 (7) ◽  
pp. 697-704
Author(s):  
Jintao Lu ◽  
Zhen Yang ◽  
Songqian Xu ◽  
Haiping Zhao ◽  
Y. Gu
Keyword(s):  
Surface Roughness ◽  
Oxidation Product ◽  
Oxidation Rate ◽  
Power Plants ◽  
Oxidation Behavior ◽  
Test Environment ◽  
Parabolic Law ◽  
Oxide Particles ◽  
Pure Steam ◽  
Oxidation Behaviors

AbstractInconel 740H alloy is a candidate material for 700°C advanced ultra-supercritical (A-USC) coal-fired power plants application as superheater/reheater tube. In this work, oxidation behavior of Inconel 740H alloy was studied in static air at 750°C and 850°C, and in dynamic pure steam at 750°C, respectively. The alloy was oxidized approximately following a parabolic law in three test environment. In the static air, the oxidation rate at 850°C was about 50 times of that at the 750°C. More NiCrMn spinal and TiO2 were detected after oxidation at 850°C. Cr2O3, however, was the main oxidation product at 750°C. In the pure steam, Cr2O3 was still the main oxidation product. The oxidation rate was about 2.6 times of that in static air, but the surface roughness was much smaller and edges of oxide particles were more blurred. There was no evidence of cracks or spallation in three test environments.

The formation of surface films at the transition between mild and severe metallic wear

1963 ◽  
Vol 273 (1355) ◽  
pp. 466-483 ◽  
Keyword(s):  
Surface Film ◽  
Surface Films ◽  
Surface Layers ◽  
Severe Wear ◽  
Wear Process ◽  
High Speeds ◽  
Mild Wear ◽  
Oxide Particles ◽  
Heavy Loads ◽  
Micro Analysis

The conditions of sliding have been found in which a transition occurs between the régimes of mild and severe wear for a leaded brass (60/40 brass containing 2% lead) sliding on hardened steel without lubrication. At light loads, low speeds, and low temperatures, mild wear begins when sufficient time is available to establish a protective surface film by oxidation; in addition, mild wear also occurs at heavy loads, high speeds and high temperatures because of an increase in the rate of oxidation. The topography and composition of the films generated on the brass during mild wear have been examined by reflexion electron microscopy and X-ray micro-analysis. The presence of a relatively large proportion of iron oxide in the surface layers, originating from the steel, increases their hardness and, in turn, causes wear of the steel itself. The variation of the rates of mild wear with load and speed is complex and, in contrast to the severe wear process, there is no unique mechanism of wear. It is concluded that mild wear of brass results from the combined effects of intermittent metal-to-metal contact, abrasion by oxide particles, and flaking of the oxide layers from the surface.

scholarly journals Can PEEK Be an Implant Material? Evaluation of Surface Topography and Wettability of Filled Versus Unfilled PEEK With Different Surface Roughness

2017 ◽  
Vol 43 (6) ◽  
pp. 456-461 ◽  
Author(s):  
Tarek Elawadly ◽  
Iman A. W. Radi ◽  
Amr El Khadem ◽  
Reham B. Osman
Keyword(s):  
Surface Roughness ◽  
Aluminum Oxide ◽  
Dental Implants ◽  
Contact Angles ◽  
Material Evaluation ◽  
Implant Material ◽  
Significant Difference ◽  
Bonferroni Test ◽  
Oxide Particles ◽  
Titanium Dental Implants

Polyetheretherketone (PEEK) composites are biocompatible materials that may overcome the esthetic and allergic problems of titanium dental implants. However, their potential for osseointegration with a subsequent survival rate is still questionable. The aim of this study was to evaluate the surface roughness and wettability of different surface-treated filled and unfilled PEEK specimens, which may be indicative of the osseointegration behavior and potential use of PEEK as an implant material. Unfilled, ceramic-filled (CFP) and carbon fiber-reinforced (CFRP) PEEK discs were prepared and left untreated or were surface treated with 50 μ, 110 μ, or 250 μ aluminum oxide particles. The roughness average (Ra) value of each disc was evaluated using a contact stylus profilometer. Their contact angles were measured to evaluate their wettability, which was compared among PEEK discs using ANOVA, followed by Bonferroni test for pairwise comparisons (P ≤ .05). Regarding the surface roughness, a significant difference was found between unfilled and filled PEEK when untreated and bombarded with 50 or 110 microns of aluminum oxide particles. For the contact angle, a significant difference was found only among the untreated PEEK materials. Among the evaluated PEEK materials, CFRP50, CFRP110 and CFP110 showed the most favorable Ra values with good wettability properties, thus being potential substrates for dental implants.

The effect of oxide particles supplied at the interface before sliding on the severe-mild wear transition

Wear ◽  
1988 ◽  
Vol 128 (2) ◽  
pp. 123-137 ◽  
Author(s):  
Akira Iwabuchi ◽  
Kiyoshi Hori ◽  
Hiroshi Kubosawa
Keyword(s):  
Mild Wear ◽  
Oxide Particles ◽  
Wear Transition

Is the Er:YAG laser affect the surface characteristics and bond strength of Y-TZP?

2021 ◽  
Vol 32 (6) ◽  
pp. 83-92
Author(s):  
Celso Bernardo de Souza-Filho ◽  
Izabela C. M. Moris ◽  
Vivian Colucci ◽  
Adriana Cláudia Lapria Faria ◽  
Érica A. Gomes
Keyword(s):  
Surface Roughness ◽  
Bond Strength ◽  
Aluminum Oxide ◽  
Vickers Microhardness ◽  
Er:Yag Laser ◽  
Surface Characteristics ◽  
Resin Cement ◽  
Dihydrogen Phosphate ◽  
Significant Difference ◽  
Oxide Particles

Abstract This study evaluated the surface characteristics and bond strength of Y-TZP treated with Er:YAG laser at different focal distances. 120 Y-TZP blocks were divided into five groups (n=24), according to the surface treatment: no treatment (C-); sandblasting with silica-coated aluminum oxide particles (C+); and Er:YAG laser application at focal distances of 1mm (Er:YAG-1), 4mm (Er:YAG-4), and 7mm (Er:YAG-7). Surface characteristics were analyzed using Vickers microhardness, confocal laser microscope, scanning electron microscopy (SEM), and X-ray diffractometer (XRD). For the bond strength test, 100 Y-TZP blocks were subdivided into two subgroups (n=10), according to the resin cement used: with (MDP+) or without 10-methacryloyloxydecyl dihydrogen phosphate (MDP-). The Vickers microhardness and surface roughness were analyzed by one-way ANOVA and bond strength by two-way ANOVA and Tukey's test for both (α=0.05). Vickers microhardness differences were not observed between the groups (p>0.05); C+ showed higher surface roughness values. SEM images showed micromorphological differences between the groups. The XRD data detected tetragonal crystals for C- and, for the other groups, tetragonal and monoclinic peaks. For bond strength, no statistically difference significance were observed among the cements with or without MDP (p>0.05) but showed significant difference between the surface treatments (C+ > C- = Er:YAG1 > Er:YAG4 = Er:YAG7) (p<0.05). Suggested that the Er:YAG laser cannot replace conventional treatment with aluminum oxide particles and the presence of MDP in the resin cement had no influence on the bond strength.

Paper 12: Mild Wear of Unlubricated Hard Steels in Air and Carbon Dioxide

1967 ◽  
Vol 182 (14) ◽  
pp. 97-106 ◽  
Author(s):  
W. T. Clark ◽  
C. Pritchard ◽  
J. W. Midgley
Keyword(s):  
Carbon Dioxide ◽  
Wear Rate ◽  
Wear Debris ◽  
Protective Layer ◽  
Spinel Oxide ◽  
Wear Process ◽  
Dry Air ◽  
Specimen Temperature ◽  
Mild Wear ◽  
Oxide Particles

A study has been made of the wear of various hard steels sliding unlubricated in dry air and in dry carbon dioxide at temperatures up to 500°C. Over the range of loads and speeds employed the wear is of a mild character and the wear debris is of oxide particles, no metallic debris being formed. The characteristics of the wear process depend on the type of oxide formed under the particular conditions of specimen temperature and surrounding atmosphere. In dry air, the wear rate increases with temperature to a maximum which depends on the type of steel, and then decreases at higher temperatures. Below the maximum, α-Fe2O3 is formed and is swept clean of the surface by the sliding process. The oxidation rate determines the wear rate which is independent of the load at constant specimen temperature. Above the maximum the spinel (Fe3O4) type oxide is formed which is adherent and wear protective. In dry carbon dioxide, spinel oxide is formed at all temperatures in the range 20–500°C and the wear rate is low, except at high temperatures when the steel becomes too soft to support the protective layer.

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