Modeling Sliding Wear: From Dry to Wet Environments - Gaseous Environment
Model Image
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Model Tree Diagram
Model Parameters
| Name | Description | Parameter Type | Value | Units | View Sub-Model |
|---|---|---|---|---|---|
| V(t) | Wear volume of the speciment at sliding time t | Variable | millimeter cube | ||
| t | sliding time | Constant (Dimensions Req.) | minutes | ||
| Ce(t) | Equivalent protective coverage of the wear surface | SubModel/Equation | View | ||
| N(t) | Quantity of wear debris particles generated per unit time on a unit area of the wear surface | Variable | Not Specified | ||
| Aa(t) | Fraction of the total apparent area of contact | Variable | Not Specified | ||
| D | Wear debris particle size | SubModel/Equation | View | ||
| f(D) | Function for the size of the newly generated wear debris particles | Variable | Not Specified | ||
| Pr(D) | Probability of a wear debris particle being removed from the wear track | Variable | Not Specified |
Failure Mechanism
| Name |
|---|
| Wear |
Component / Technology Types
Characteristics
| Title | Description |
|---|---|
| Fatigue Approach to Wear | Model considers low cycle fatigue to be the mechanism responsible for the generation of wear debris. |
| Retained Wear Debris | This model considers the effects of wear debris particles that are retained between the contacting surfaces. This includes both the generation of additional wear debris as well as the cold-welding of hardened, wear-protective layers on the sliding surface. |
| Oxygen and Other Reactive Species | This model considers the effects of oxygen partial pressure and other reactive species in the determination of wear debris particle size (D) and surface energy (gamma) of the contacting surfaces). |
| Surface Energy | The surface energy is related to the partial pressure of the reactive species by the Gibbs' adsorption isotherm and the classical Langmuir gas adsorption isotherm. |
| Max Vertical Strain | The maximum vertical strain in the wear surface due to the frictional action (Emax) is approximately equal to the strain limit of the material at the formation of the wear debris. |
| Wear-Protective Layer | The model accounts for compact layers as well as glaze layers on the wear surface generated from debris particles, the latter being the most effective. |
| Vret(t) Parameter | The volume of wear debris retained between the sliding surfaces [Vret(t)] is a sub-model of this model. However, as it's value is required to solve one of it's own sub-models, it's described as a Constant(Testing Req'd) for that sub-model. |
Assumptions
| Title | Description |
|---|---|
| Wear Rate of Protective Layers | The wear rate of the protective layers formed by debris particles on the sliding surface is assumed to be negligible compared to other areas uncovered by such wear-protective layers. |
| Retained Particles | It's assumed that all retained particles are compacted eventually to form wear-protective layers of an average thickness ranging from 2-15 micrometers. This assumption is to establish the equation to determine the coverage of the wear surface by compact layers (Cc). |
Limitations
| Title | Description |
|---|---|
| N/A | N/A |
Constraints
| Title | Description |
|---|---|
| N/A | N/A |
Uncertainty Limits
| Type | Uncertainty |
|---|---|
| N/A | N/A |
Data or Information Needed from Outside Sources
| Category | Source | Description |
|---|---|---|
| Material Properties | User | Partial pressure of the reactive species (pA) |
| Scaling Factor | User | Constant in the Langmuir isotherm representing the ratio between the rate constants for adsorption and desorption of a gas on a solid (b), testing required |
| Material Properties | User | Number of bonds per unit area along the crack-plane (NA) |
| Material Properties | User | Surface energy of a solid in a vacuum (γ0) |
| Material Properties | User | Maximum vertical strain in the wear surface due to frictional action (εmax) |
| Material Properties | Manufacturer | Elastic modulus (E) |
| Mechanical Properties | Manufacturer | Poisson's Ratio (ν) |
| Material Properties | User | Critical glaze oxide thickness for effective wear protection (δc) |
| Physical Dimension(s) | User | An area of the compact layer that develops into a glaze layers after a period of tcg [dAc(τ)] |
| Physical Dimension(s) | User | Fraction of the total apparent area of contact [Aa(t)] |
| Physical Dimension(s) | User | Average thickness of wear protective layers (δ) |
| Physical Dimension(s) | User | Quantity of wear debris particles generated per unit time on a unit area of the wear surface [N(t)] |
| Physical Dimension(s) | User | Function for the size of the newly generated wear debris particles [f(t)] |
| Material Properties | User | Probability of a wear debris particle being removed from the wear track [Pr(t)] |
Bibliographic Citation
| Published Status | Source Type | Title | Authors |
|---|---|---|---|
| Published | Article/Paper | Modelling Sliding Wear: From Dry to Wet Environments | Jiaren Jang, M. M Stack |
| Abstract/Summary |
|---|
| Corrosive species in various forms exist widely in the environment and can significantly affect wear behaviour of materials, usually accelerating wear. Under conditions where the environments are seemingly non-deleterious in terms of corrosivity, some species from the environment can still affect the tribological behaviour of materials. It is thus extremely important to recognise the roles of reactive species in affecting the tribological processes and to understand the processes of tribo-corrosion interactions. In this paper, the mechanisms of wear debris generation and the roles of reactive species in the generation of wear debris during sliding wear in gaseous or aqueous environments are discussed. The effect of environment on the development of wear-protective layers is described. Based on the proposed mechanisms, mathematical models for sliding wear in both dry and aqueous environments are outlined, and the validity of the models is assessed against experimental data in sliding conditions. |
| Report # | Publication Name | Volume # | Publisher Name |
|---|---|---|---|
| N/A | Wear | 2612006 | N/A |
| Publication Date | Pages | Source URL | Copyright Info |
|---|---|---|---|
| 2006-05-02 | 954-965 | http://www.sciencedirect.com | 2006 Elsevier B.V. All rights reserved |
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