Wear Mechanism of Ceramic Materials in Dry Rolling Friction

1986 ◽  
Vol 108 (4) ◽  
pp. 522-526 ◽  
Author(s):  
S. S. Kim ◽  
K. Kato ◽  
K. Hokkirigawa ◽  
H. Abe´
Keyword(s):  
Silicon Nitride ◽  
Wear Rate ◽  
Contact Area ◽  
Ceramic Materials ◽  
Rolling Friction ◽  
Bearing Steel ◽  
Rolling Contact ◽  
Hertzian Contact ◽  
Real Contact Area ◽  
Wear Process

Wear tests in dry rolling contact were carried out at room temperature on five ceramic materials, such as silicon nitride, silicon carbide, cermet, titania, and alumina. The results showed that wear rate of silicon nitride was smaller than any of the other ceramic materials and bearing steel. Observations of worn surface and wear debris revealed that ceramic materials have two types of wear, one related to real contact area and another related to Hertzian contact area. It was also found that brittle fracture dominates the wear process of ceramic materials in dry rolling contact. Based on the experimental results, wear rate of ceramic materials was expressed with a new nondimensional parameter.

scholarly journals Elastic-contact-based tool-path planning for free-form surface in belt grinding

2019 ◽  
Vol 11 (1) ◽  
pp. 168781401881992 ◽  
Author(s):  
Junde Qi ◽  
Bing Chen
Keyword(s):  
Path Planning ◽  
Contact Area ◽  
Tool Path ◽  
Hertzian Contact ◽  
Free Form ◽  
Real Contact Area ◽  
Elastic Contact ◽  
Tool Path Planning ◽  
Belt Grinding ◽  
Free Form Surface

As for the fact that the majority of current researches take the technology of tool-path planning for free-form surface only as a geometrical problem, which is not suitable for belt grinding because of the elastic deformation of the grinding belt that leads to a variable contact, in this article, the tool-path planning method for belt grinding is developed from the elastic contact point of view. Based on the Hertzian contact theory and taking the grinding force into consideration, a calculation method of the contact area between the belt and the workpiece is presented. Then, a tool-path planning model is presented based on the real contact area to meet the full coverage. In addition, an optimization model based on the constant scallop-height is further developed to meet the high form accuracy of the workpiece. First, a modified model for the material removal depth is developed based on the Preston equation. Then, according to the curvature of the contact surface, three situations are analyzed and the calculation methods of the tool-path interval are given. Finally, experiments on the simulation blade are conducted, and the experimental results show the effectiveness of the method in this article.

scholarly journals On a Simplified Model for Numerical Simulation of Wear During Dry Rolling Contacts

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
L. Chevalier ◽  
A. Eddhahak-Ouni ◽  
S. Cloupet
Keyword(s):  
Contact Area ◽  
Power Distribution ◽  
Contact Problems ◽  
Rolling Contact ◽  
Normal Loading ◽  
Fast Determination ◽  
Wear Process ◽  
Simplified Approach ◽  
Rolling Contacts

We deal with rolling contact between quasi-identical bodies. As normal and tangential problems are uncoupled in that case, the simplified approach to determine contact area and normal loading distribution for rolling contact problems is presented in Sec. 2. In Sec. 3, the solution of the tangential problem is used to update the rolling profiles and enables to follow the wear evolution versus time. The method used to solve the normal problem is called semi-Hertzian approach with diffusion. It allows fast determination of the contact area for non-Hertzian cases. The method is based on the geometrical indentation of bodies in contact: The contact area is found with correct dimensions but affected by some irregularities coming from the curvature’s discontinuity that may arise during a wear process. Diffusion between independent stripes smoothes the contact area and the pressure distribution. The tangential problem is also solved on each stripe of the contact area using an extension of the simplified approach developed by Kalker and called FASTSIM. At the end, this approach gives the dissipated power distribution in the contact during rolling and this power is related to wear by Archard’s law. This enables the profiles of the bodies to be updated and the evolution of the geometry to be followed.

Geometrical Effects on the Wear of Polymers and Carbons

1975 ◽  
Vol 97 (2) ◽  
pp. 187-194 ◽  
Author(s):  
J. K. Lancaster
Keyword(s):  
Wear Rate ◽  
Contact Area ◽  
Wear Process ◽  
Wear Rates ◽  
Small Areas ◽  
Bearing Materials ◽  
Geometrical Effects ◽  
Basic Studies ◽  
Wear Tests

Accelerated wear tests involving small areas of contact are frequently used both as an aid to materials selection for dry bearings and for basic studies of wear. It is shown that whilst a general correlation may exist between the wear rates of polymer composites in accelerated tests and during operation as dry journal bearings, discrepancies can occur. The latter are primarily attributable to the differences in the apparent areas of contact. The various ways in which the apparent contact area may influence the wear of dry bearing materials—polymers and carbons—are examined and discussed. Particular attention is given to the role of transfer to, and polishing of the counterface metal during the early stages of sliding. The wear process of polymers and carbons during sliding, against relatively smooth metals is often assumed to be one of fatigue on a localised asperity scale. The implications of this process on the variations of wear rate with load and counterface surface roughness are examined. The use of very small contact areas, to increase the sensitivity of wear measurement, can give rise to misleading variations of wear rate with load, resulting from the trapping of debris within the contact area.

scholarly journals The role of synthetic oils in controlling hydrogen permeation of rolling/sliding contacts

RSC Advances ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 726-738
Author(s):  
Hiroyoshi Tanaka ◽  
Monica Ratoi ◽  
Joichi Sugimura
Keyword(s):  
Wear Rate ◽  
Hydrogen Content ◽  
Wear Track ◽  
Hydrogen Permeation ◽  
Bearing Steel ◽  
Rolling Contact ◽  
Sliding Contacts ◽  
Base Oil ◽  
Oil Type

Hydrogen content and wear rate in bearing steel under rolling contact depend on the base oil type and the composition of tribofilm they generate on the wear track.

scholarly journals ON A STEPPING METHOD FOR THE NON STEADY ROLLING CONTACT RESOLUTION

1970 ◽  
Vol 40 (2) ◽  
pp. 131-136
Author(s):  
Anissa Eddhahak ◽  
Luc Chevalier
Keyword(s):  
Finite Difference ◽  
Wear Rate ◽  
Difference Scheme ◽  
Contact Area ◽  
Finite Difference Scheme ◽  
Life Time ◽  
Contact Problems ◽  
Rolling Contact ◽  
Transient Phenomena ◽  
Numerical Tools

The importance of contact and surface problems in industrial machining requires specific studies by tribological researchers to help engineering developments. During cyclic rolling, mechanical components may fail from wear fatigue and it is necessary to develop numerical tools based on simplified approaches to quantify their life time. Numerous wear equations reported in literature have shown that the wear rate is in most cases linked to the traction and the velocities which occur in the contact area. The knowledge of these parameters at every time enables us to follow the wear evolution in the softer material. In this paper, we suggest a stepping method to solve the non steady rolling contact problems. This method is based on the well known approach Fastsim of Kalker and integrates a numerical finite difference scheme to describe the evolution of transient phenomena occurring during non steady rolling contact.Key Words: Rolling Contact; Non Steady; Stepping Approach; Fastsim.DOI: 10.3329/jme.v40i2.5354Journal of Mechanical Engineering, Vol. ME 40, No. 2, December 2009 131-136

A Contribution of Fractal Geometry to Characterization of Wear Process

2005 ◽  
Vol 290 ◽  
pp. 276-279
Author(s):  
Miriam Kupková ◽  
Martin Kupka ◽  
Emőke Rudnayová ◽  
Ján Dusza
Keyword(s):  
Fractal Dimension ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Fractal Geometry ◽  
Wear Test ◽  
Ceramic Materials ◽  
Fractal Curve ◽  
Wear Process ◽  
Sliding Distance

Irregular evolution of friction coefficient, recorded during the ball-on-disc test on Si3N4 based ceramic materials, was analysed by means of fractal geometry methods. Tests were carried out at room temperature, in air and without any lubricant. It was proven that the friction coefficient trace, considered as a geometric object, has the property of a fractal curve. The fractal dimension of this curve increased with increasing wear rate measured in a corresponding wear test. This could indicate the possible correlation between the wear rate and the fractal dimension of friction coefficient as a function of sliding distance (time).

scholarly journals Some Basic Reflections About the Influence of Non-Metallic Inclusions on Rolling Contact Fatigue of Bearing Steels

1992 ◽  
Author(s):  
Hans-Jürgen Böhmer
Keyword(s):  
Residual Stresses ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Behaviour ◽  
Mechanical Analysis ◽  
Bearing Steel ◽  
Rolling Contact ◽  
Hertzian Contact ◽  
Notch Effect ◽  
Compressive Residual Stresses

The detrimental influence of inclusions on rolling contact fatigue behaviour of bearing steel is well known and empirically described. Yet only a few publications exist where the effect of inclusions is investigated analytically. This paper presents a new method to describe the influence of inclusions based on a mechanical analysis. From this analysis some general effects of inclusions on material stress and behaviour in rolling contact fatigue were concluded. The actual “notch effect” of inclusions is qualitatively independent on their specific properties, even if they are more pliable or stiffer than the matrix. Only the amount of the notch effect is — to a certain extent — dependent on their respective properties. Many discrepancies between classical theory of Hertzian contact and damage analysis of rolling element bearings can be explained by this analysis. The correct appraise of compressive residual stresses in rolling contact fatigue is strongly bound to the consideration of inclusions. It is shown that compressive residual stresses have the greatest benefit if they are about 15% of the applied Hertzian pressure. Exceeding this value may be detrimental.

Real Contact Area of Fractal-Regular Surfaces and Its Implications in the Law of Friction

2004 ◽  
Vol 126 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Shao Wang
Keyword(s):  
Fractal Dimension ◽  
Contact Area ◽  
Hertzian Contact ◽  
Real Contact Area ◽  
Contact Ratio ◽  
Regular Surface ◽  
Fractal Surfaces ◽  
Linear Friction ◽  
Fractal Domains ◽  
Macroscopic Shape

The concept of a fractal-regular surface, with a dual-section power spectrum, has been implemented in an elastic-plastic contact analysis. Under certain assumptions, the analysis of individual fractal domains can be decoupled from that of the macroscopic shape. Due to the increase in the number of contacting fractal domains associated with a macroscopic contact expansion, the contact area-load relationship for fractal-regular surfaces is nearly linear, with a load exponent of 1-1.11, in contrast to 1-1.33 for fractal surfaces. Thus, the Amontons law of friction can be reasonably explained with fractal-regular surfaces under the assumption of a linear friction-area relationship. The distribution of the local real-to-apparent contact ratio in a nominally Hertzian contact was found to vary with the fractal dimension. The plastic contact ratio tends to be more uniformly distributed as the fractal dimension approaches unity.

Effect of normal load on the frictional and wear behaviour of carbon fiber in tow-on-tool contact during three-dimensional weaving process

2020 ◽  
pp. 152808372094461
Author(s):  
Ning Wu ◽  
Ximing Xie ◽  
Jie Yang ◽  
Yajie Feng ◽  
Yanan Jiao ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Contact Area ◽  
Normal Load ◽  
Three Dimensional ◽  
Hertzian Contact ◽  
Wear Behaviour ◽  
Real Contact Area ◽  
The Real ◽  
Real Contact ◽  
Fracture Damage

The effect of normal load on the frictional and wear behaviour of carbon fiber is investigated by simulating the tow-on-tool friction relevant to the beating-up motion of three-dimensional (3 D) weaving process. The true number of contact filaments over a range of normal loads is calculated by characterizing the cross-section parameters of carbon tow. The real contact area is calculated on the basis of the filaments amount by Hertzian contact model. The friction force values obtained from multiplying the real contact area with shear strength are closely with the measured results. The coefficient of friction increases with the increase of normal loads. When the normal load is 250, 400 and 600 mN, the tensile loss rate of the carbon tow after friction test is 6.3%, 23.2% and 42.4% respectively. The filaments reveal multiple fracture damage patterns which are caused by stretching, shearing and compression during the weaving process.

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