Fretting wear occurs when two bodies in contact are
subject to small oscillatory displacements.
This wear phenomenon is common in many industrial applications, such as
gears, couplings, bearings, screws, valves and joints where vibrations
occur. It has been shown that many
factors affect the fretting wear rate, e.g. the normal load, sliding distance,
geometry of the bodies, surface roughness, material properties, lubrication
status, temperature and presence of third bodies. Fatigue has also been the subject of much
investigation over the past century.
Fatigue damage is observed in the form of microcracks, debonding, etc.
in the vicinity of stress risers (e.g. inclusions, voids etc.) within the
materials. The stress component causing
fatigue failure can be normal, shear, or a combination due to a compound state
of loading. In order to investigate the
shear mode of fatigue failure, torsional fatigue testing has been the subject
of many studies. Shear mode of failure
is of significant importance in triaxial state of stress present for ball and
rolling element bearings and machine component which are subject to fretting
fatigue. A number of different
experimental and numerical techniques have developed to study the torsion fatigue
and fretting wear of materials at different conditions. An in-situ fretting wear
measurement technique was developed to investigate the effects of temperature
on the coefficient of friction and wear rate of Inconel 617 in fretting wear in
air and helium environments. Due to the
importance of the shear mode of stress in fretting fatigue phenomenon, another
set of experiments were designed to measure high cycle torsional fatigue
properties of Inconel 617 at elevated temperatures. An MTS torsional fatigue test rig was
modified with customized mechanical grips and cooling fins. In order to achieve the objectives of
analytical aspects of this investigation, a 3D elastic-plastic finite element
model was developed to examine the torsional fatigue damage in Inconel 617
material at high temperatures. Then, a
3D finite element model was developed to study fretting wear of similar
materials in Hertzian line and circular contacts. The wear law incorporated in this model is
based on the accumulated dissipated energy law.
The FEM was used to investigate partial slip regime. Then, the model was verified by performing
several experimental tests for the circular contact configuration. During fretting wear, the generated wear
debris is of significant importance. A
finite element model was created to study the third body effects on fretting
wear of Hertzian contacts in the partial slip regime. Both first bodies and third bodies were
modeled as elastic-plastic materials.
The effect of the third body particles on contact stresses and
stick-slip behavior was investigated.
The influence of the number of third body particles and material
properties including modulus of elasticity, hardening modulus, and yield
strength were analyzed. Finally, A new thermally cured polymer-graphene-zinc
oxide-based solid lubricant was developed that reduced friction and wear
significantly during the sliding wear of bearing steel under extreme contact
pressure and long duration. The dry solid coating composite was made from a
mixture of graphene, zinc oxide, and a specific industrial binder and then
laminated on the surface of 52100 steel disks using the spin-coating technique.
After ∼3000 cycles, the 15 μm thick coating created a significant reduction in
the steel's coefficient of friction (approximately 82%) and wear loss compared
to the uncoated surfaces. Following the tribological<a></a>
examination, scanning electron microscopy, energy dispersive X-ray
spectroscopy, X-ray diffraction, and Raman spectroscopy were conducted to
determine the topography and morphology of the composite coating and resultant
wear scars.
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/16649557 |
| Date | 29 October 2021 |
| Creators | Arman Ahmadi (8520414) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/thesis/EXPERIMENTAL_AND_ANALYTICAL_STUDY_IN_FATIGUE_AND_WEAR_OF_STEEL_AND_NICKEL-BASED_ALLOYS/16649557 |
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