Development of a Fretting Wear Evaluation Method in the Nuclear Fuel Fretting by Using a Wear Scar Shape

2007 ◽  
Vol 26-28 ◽  
pp. 1231-1234
Author(s):  
Young Ho Lee ◽  
Hyung Kyu Kim
Keyword(s):  
Nuclear Fuel ◽  
Evaluation Method ◽  
Normal Load ◽  
Wear Scar ◽  
Wear Volume ◽  
Critical Ratio ◽  
Applied Normal Load ◽  
Scar Size ◽  
The Relationship ◽  
Wear Tests

In order to evaluate the effects of a variation of a supporting springs' shape on the wear behavior of a nuclear fuel rod, sliding wear tests have been performed in room temperature air and water. The objective of the tests is to quantitatively evaluate the relationship between a worn area and a wear volume, and the formation behavior of a worn area with a variation of the slip amplitudes, applied normal loads and supporting spring shapes. The results indicated that the variation behavior of the volume and the wear scar size was influenced by the contact shape between the springs and the fuel rods. Also, it was found to be possible to evaluate a critical ratio (Tc) for each spring shape and test condition when the T was defined as the ratio of an applied normal load (Ln) to a wear scar size (At). Below this Tc, the wear volume was rapidly increased and the Tc was determined by a variation of the At under the same applied normal load condition. This result enables us to evaluate a wear resistant spring shape by using an analysis of a wear scar after wear tests have been completed. Based on the above results, the relationship between At and a worn area (Aw), a wear mechanism and an evaluation method for a wear resistance were discussed.

scholarly journals On the precise measurement capability of the direct microscopic measurement method for wear volume characterization

2018 ◽  
Vol 188 ◽  
pp. 02007
Author(s):  
Enbiya Türedi
Keyword(s):  
Normal Load ◽  
Wear Test ◽  
Optical Microscope ◽  
Bearing Steel ◽  
Wear Scar ◽  
Wear Volume ◽  
Measurement Capability ◽  
Comparison Results ◽  
Novel Method ◽  
Microscopic Measurement

There are plenty of methods for determining the wear volume after a wear test. Due to the geometrical assumptions, some of them could unfortunately lead to mistaken results. It has been shown that a novel method, the direct microscopic measurement, is able to calculate the wear volume on a specimen surface very precisely and accurately [1-2]. It is based on creating a series of line profiles perpendicular to the wear scar. This novel method, however, needs to be characterized in terms of measurement limitations and minimum detectable volume capability. For example, how small or how shallow a wear scar could be calculated or measured with this method, must be determined. For this purpose, it has been prepared a series of wear test specimens exposed to the different amounts of wear in a “pin-on-disk” type test rig. As specimens, two different non-ferrous mold materials, Al bronze alloys, were selected and prepared metallographically. Counterpart materials were inox steel and bearing steel balls with diameter of 6 mm. Normal load was set to 5 N. Test configurations were set to 1, 5, 10 and 100 m of sliding distance values, in turn. Wear tests were conducted in according to ASTM G99 standard. Wear volume results were determined both direct microscopic measurement and also a 3D optical microscope methods. Comparison results showed that the novel method could be successfully used for wear volume calculations even with small amounts of wear volume conditions.

Characterisation of Plasticity Response for Reciprocating Sliding Wear Test of Ti-6Al-4V under Variables Normal Load

2015 ◽  
Vol 1087 ◽  
pp. 350-354 ◽  
Author(s):  
D. Harun ◽  
Abdul Latif Mohd Tobi ◽  
A. Singh Chaal ◽  
Ramdziah Md. Nasir
Keyword(s):  
Plastic Deformation ◽  
Sliding Wear ◽  
Wear Track ◽  
Normal Load ◽  
Surface Profile ◽  
Wear Test ◽  
Wear Scar ◽  
Reciprocating Sliding ◽  
Applied Normal Load ◽  
Reciprocating Sliding Wear

Reciprocating sliding wear test of uncoated titanium alloy, Ti-6Al-4V is investigated using pin-on-flat arrangement under variable applied normal load. The wear scar produced by the reciprocating sliding wear test is analysed by surface profile examination using 2D and 3D optical microscope (OM) and Scanning Electron Microscope (SEM). Through SEM, the energy-dispersive X-ray spectroscopy (EDX) is used to characterise the composition of the substance on the worn surface. The hardness value of the wear scar is investigated at three regions which are; worn, unworn and the end of the wear track using Micro Vickers Hardness Test. The presence of moderate oxygen composition and the increasing in hardness value at the end of wear track suggesting evidence of plastic deformation. The increase in hardness value at the end of wear track indicates increase in plastic deformation with increasing applied normal load.

Effect of the Substrate on the Fretting Wear of Sputtered W-Si-N Coatings Against Steel

2005 ◽  
Author(s):  
M. C. Gaspar ◽  
A. Ramalho ◽  
A. Cavaleiro
Keyword(s):  
Normal Load ◽  
Tangential Force ◽  
Relative Displacement ◽  
Fretting Wear ◽  
Wear Volume ◽  
Aisi 52100 ◽  
Aisi 52100 Steel ◽  
Steel Substrates ◽  
The Relationship ◽  
Amorphous Coatings

Fretting tests of sputtered W-Si-N amorphous coatings were performed on both cemented tungsten carbide with 6wt.% of Co and AISI 310 steel substrates against spherical AISI 52100 steel counterbodies. The normal load and the amplitude of relative displacement were varied. The evolution of the tangential force during the test was recorded. At the end of each test, the volume and the surface morphology of the wear scars were measured and analyzed. The relationship between the dissipated frictional energy and the wear volume was calculated. The results allowed plotting fretting maps identifying the occurrence of different fretting regimes.

An Elastic Adhesion Model for Contacting Cylinder and Perfectly Wetted Plane in the Presence of Meniscus

2007 ◽  
Vol 129 (2) ◽  
pp. 231-234 ◽  
Author(s):  
Y. F. Peng ◽  
G. X. Li
Keyword(s):  
Relative Humidity ◽  
Normal Load ◽  
Adhesive Contact ◽  
Laplace Pressure ◽  
Contact Radius ◽  
Adhesive Interaction ◽  
Applied Normal Load ◽  
Adhesion Model ◽  
The Relationship

The present research concerns the elastic contacting adhesion of a cylinder with a perfectly wetted plane in the presence of a meniscus. The Laplace pressure due to the meniscus is simplified utilizing Maugis–Dugdale approximation. Then the Baney and Hui solution and its extension are used to solve the adhesive interaction of the cylinder and the plane. Simulations of the relationship between the adhesive contact radius and the applied normal load are performed, and the influence of the relative humidity on the relationship is also discussed.

An Experimental Study of the Fretting Wear Coefficient for the Dimple-Gimbal Interface

2014 ◽  
Author(s):  
Zhengqiang Tang ◽  
Frank E. Talke
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Experimental Study ◽  
Normal Load ◽  
Wear Scar ◽  
Fretting Wear ◽  
Wear Volume ◽  
Wear Coefficient ◽  
Scanning Electron

The effect of normal load on fretting wear of the dimple-gimbal interface is investigated. The wear volume, the wear coefficient and the friction-displacement loops are studied as a function of the number of fretting wear cycles. The wear volume of the dimple is calculated from the radius of the wear scar obtained using scanning electron microscopy. The results show that the wear coefficient decreases with an increase in the number of fretting wear cycles.

Increase of the load carrying capacity of aluminum 2024-T3 by means of a NiP-CrC-DLC coating

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
Mariana H. Staia ◽  
Eli S. Puchi-Cabrera ◽  
Y. Y. Santana ◽  
J. G. La Barbera-Sosa ◽  
Alain Iost ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Sliding Wear ◽  
Normal Load ◽  
Dry Sliding Wear ◽  
Contact Radius ◽  
Wear Volume ◽  
Dlc Coating ◽  
Stability Point ◽  
Wear Tests

The present investigation has been conducted in order to evaluate the tribological behavior of an AA2024-T3 aluminum alloy, coated with a NiP-CrC-DLC coating. The effect of NiP as intermediate layer was evaluated by carrying out calculations using ELASTICA© in order to determine its adequate thickness needed to avoid the plastic deformation of the substrate, ensuring then the integrity of the coating. To evaluate the efficiency of these calculations, a number of dry sliding wear tests were performed employing a ball-on-disk configuration, where alumina balls of 6 mm in diameter were used as counterpart. The sliding wear tests were carried out up to a sliding distance of 800 m, with a normal load of 5 N, a linear speed of 5 cm/s and a contact radius of 3 mm. The wear tracks were analyzed by means of scanning electron microscopy (SEM) techniques coupled with energy dispersive spectroscopy (EDS). The wear volume was determined by means of optical profilometry. The results indicate that, under the present testing conditions, the NiP-CrC-DLC coating exhibits a satisfactory behavior from the mechanical stability point of view when the thickness of the NiP layer is higher than 60 μm, since no surface failures were observed at the end of the tests. For the coated system, the magnitude of the friction coefficient was found to be of approximately 0.1 and that of the wear rate was of about 2.31 ± 0.09 x 10-16 m3/N.m. On the contrary, for the uncoated substrate, the friction coefficient was of approximately 0.5 and the wear rate of 5.46 x 10-13 m3/N.m, that is to say, 3 orders of magnitude greater than that determined for the coated system.

The Predictions of the Fretting Wear between Supporting Grids and Cladding Tubes of Nuclear Fuel Rod

2006 ◽  
Vol 326-328 ◽  
pp. 1243-1246
Author(s):  
Young Chang Park ◽  
Yong Hwan Kim ◽  
Seung Jae Lee ◽  
Young Ze Lee
Keyword(s):  
Nuclear Fuel ◽  
Nuclear Reactor ◽  
Normal Load ◽  
Fretting Wear ◽  
Wear Coefficient ◽  
Flow Induced Vibration ◽  
Stick Slip ◽  
Slip Mechanism ◽  
Fuel Rod ◽  
Wear Tests

Fretting can be defined as the oscillatory motion with very small amplitudes, which usually occur between two contacting surfaces. Fretting wear is the removal of material from contacting surfaces through fretting action. This fretting wear, which occurs between cladding tubes of nuclear fuel rod and grids, causes in damages the cladding tubes by flow induced vibration in a nuclear reactor. In this paper the fretting wear tests were performed with two types of cladding tubes and three types of supporting grids in water. Fretting wear tests were done using various applied loads. From the results of fretting tests, the wear amounts of tube materials can be predictable by obtaining the wear coefficient using the work rate model. Depending on various normal load, tube materials, and supporting grid shapes, distinctively different wear scar of fretting and stick-slip mechanism can occur.

An experimental and theoretical study of the abrasion performance of digital light processing parts

2020 ◽  
pp. 095440542098133
Author(s):  
Mehdi Kazemi ◽  
Abdolreza Rahimi
Keyword(s):  
Layer Thickness ◽  
Normal Load ◽  
Digital Light Processing ◽  
One Step ◽  
Pin On Disk ◽  
The Relationship ◽  
Influential Parameters ◽  
Disk Method ◽  
Normal Angle

Generally, interactions at surface asperities are the cause of wear. Two-Thirds of wear in industry occurs because of the abrasive or adhesive mechanisms. This research presents an analytical model for abrasion of additive manufactured Digital Light Processing products using pin-on-disk method. Particularly, the relationship between abrasion volume, normal load, and surface asperities’ angle is investigated. To verify the proposed mathematical model, the results of this model are verified with the practical experiments. Results show that the most influential parameters on abrasion rate are normal load and surface’s normal angle. Abrasion value increases linearly with increasing normal load. The maximum abrasion value occurs when the surface’s normal angle during fabrication is 45°. After the asperities are worn the abrasion volume is the same for all specimens with different surface’s normal angle. Though layer thickness does not directly affect the wear rate, but surface roughness tests show that layer thickness has a great impact on the quality of the abraded surface. When the thickness of the layers is high, the abraded surface has deeper valleys, and thus has a more negative skewness. This paper presents an original approach in abrasion behavior improvement of DLP parts which no research has been done on it so far; thus, bringing the AM one step closer to maturity.

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