Cracking Induced by Fretting of Aluminium Alloys

1997 ◽  
Vol 119 (1) ◽  
pp. 36-42 ◽  
Author(s):  
Z. R. Zhou ◽  
L. Vincent
Keyword(s):  
Aluminium Alloys ◽  
Small Amplitude ◽  
Crack Nucleation ◽  
Normal Load ◽  
Fatigue Cracking ◽  
Fretting Fatigue ◽  
Fretting Wear ◽  
Partial Slip ◽  
Material Loss ◽  
Main Effects

Fretting-wear and fretting-fatigue loadings can both result in wear (material loss) and in crack nucleation and propagation (fatigue process). This paper deals with cracking induced by small amplitude displacements in the case of aeronautic aluminium alloys. The two sets of fretting maps are introduced: running condition fretting map is composed of partial slip (sticking), mixed fretting and gross sliding regime; material response fretting map is associated with two macro-degradation modes. Crack nucleation and propagation are analysed for every fretting regime. The mixed fretting regime appeared most detrimental with regards to fatigue cracking. Slip amplitude and normal load main effects discussed for fretting wear can be used to justify the fatigue limit decrease often obtained for fretting fatigue experiments.

Transition in the Fretting Phenomenon Based on the Variabile Coefficient of Friction

2012 ◽  
Vol 463-464 ◽  
pp. 343-346
Author(s):  
Stefan Ghimişi ◽  
Liliana Luca ◽  
Gheorghe Popescu
Keyword(s):  
Small Amplitude ◽  
Crack Nucleation ◽  
Tangential Force ◽  
Fretting Wear ◽  
Partial Slip ◽  
Fatigue Properties ◽  
Fatigue Crack Nucleation ◽  
Slip Regime ◽  
Mixed Regime ◽  
Slip Transition

Fretting is now fully identified as a small amplitude oscillatory motion which induces a harmonic tangential force between two surfaces in contact. It is related to three main loadings, i.e. fretting-wear, fretting-fatigue and fretting corrosion. Fretting regimes were first mapped by Vingsbo. In a similar way, three fretting regimes will be considered: stick regime, slip regime and mixed regime. The mixed regime was made up of initial gross slip followed by partial slip condition after a few hundred cycles. Obviously the partial slip transition develops the highest stress levels which can induce fatigue crack nucleation depending on the fatigue properties of the two contacting first bodies. Therefore prediction of the frontier between partial slip and gross slip is required.

scholarly journals Fretting Wear Behavior and Damage Mechanisms of Inconel X-750 Alloy in Dry Contacts

2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Ibrohim A. Rustamov ◽  
Ozoda Sh. Sabirova ◽  
Zixi Wang ◽  
Yuming Wang
Keyword(s):  
Wear Behavior ◽  
Normal Load ◽  
Fretting Wear ◽  
Partial Slip ◽  
Test Duration ◽  
Material Transfer ◽  
Friction Forces ◽  
Frictional Properties ◽  
Load Tests ◽  
Oxidation Mechanisms

Tribological behavior of the Inconel X-750 alloy disk subjected to fretting against the GCr15 steel ball was investigated in an ambient laboratory air with relative humidity of 55–65%. A high-frequency oscillating Optimol SRV 4 tribometer was employed to execute dry fretting tests in the partial and gross slip regimes under constant 100 N normal load. Tests were carried out for 10, 30, and 90 minutes, and the friction forces vs. displacement amplitudes were monitored during the test duration. Posttest examinations were conducted utilizing advanced tools such as 3D optical surface profiler, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). The main objective was to obtain wear scar evolutions, frictional properties, and degradation mechanisms under the different running conditions over time. It was found that fretting wear behaviors of friction pairs were strongly influenced by fretting regimes. Degradation evolutions were greatly influenced by fretting time during partial slip regimes, i.e., evolving from asperity deformation and slight damage to the fatigue crack and material transfer. However, the combination of adhesive, abrasive, delamination, and wear oxidation mechanisms was repeated during the entire gross slip fretting process.

Fretting Fatigue Design of Subsea Connectors: A Generalised Approach to Testing

2020 ◽  
Author(s):  
H. Andresen ◽  
D. A. Hills ◽  
Anders Wormsen ◽  
K. A. Macdonald
Keyword(s):  
Crack Nucleation ◽  
Normal Load ◽  
Asymptotic Methods ◽  
Fretting Fatigue ◽  
Test Design ◽  
Frictional Contacts ◽  
Fatigue Design ◽  
Geometrical Features ◽  
Fatigue Data ◽  
Constant Normal Load

Abstract In this paper fretting fatigue is addressed as a potential design consideration for wellhead connectors. The study of near-edge relative motion for frictional contacts under constant normal load is described using analytical, numerical and asymptotic methods. Based on published fretting fatigue experimental data an argument is drawn for a generalised fretting fatigue test design. We do this by reducing the parameters responsible for crack nucleation to the smallest number possible and thereby revealing the fretting fatigue strength as a material property independent of geometrical features. Easy to apply recipes are described and thoughts on a potential apparatus are shared with the reader. Commercial potential lies in the wide-ranging applicability of experimental results across many prototypes and loadings once an appropriate amount of fretting fatigue data has been generated for the material in question.

Fretting Wear Behavior and Damage Mechanisms of Inconel X-750 Alloy in Dry Contact Condition

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Ibrohim Rustamov ◽  
Gaolong Zhang ◽  
Margarita Skotnikova ◽  
Yuming Wang ◽  
Zixi Wang
Keyword(s):  
Normal Load ◽  
Fatigue Cracks ◽  
Contact Condition ◽  
Fretting Wear ◽  
Partial Slip ◽  
Small Displacement ◽  
Stick Slip ◽  
Damage Mechanisms ◽  
Normal Loading ◽  
Dry Contact

Frictional and fretting wear behaviors of Inconel X-750 alloy against GCr15 steel ball were investigated in dry contact condition with ∼60% air humidity. Fretting tests were run at the high frequency tribosystem SRV 4 in room temperature and ball-on-flat contact configuration were adopted with the relative oscillatory motion of small displacement amplitude (40 μm). Sliding regimes, wear volumes, frictional properties, and material damage mechanisms were studied with regard to different normal loading and test durations. After the tests, the worn surface morphologies were analyzed by three-dimensional (3D) optical surface profiler, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) to distinguish fretting running conditions and material responses for different test cases. It was found that the material removals by abrasive and adhesive wear, debris formation and oxidization, and wear delamination were the main damage mechanisms under the lower normal load where the full slide or gross slip regime (GSR) was dominant between the contact surfaces. On the other hand, fretting regime was found to be a stick-slip or a partial slip at greater loads where damage mechanisms were correlated with deformed asperities, fatigue cracks, and thick layer removal due to highly concentrated cyclic stresses. Time dependence was crucial during GSR where the wear volume increased substantially; however, the wear volumes and scars sizes were consistent over time because of stick-slip effects under the higher normal load.

Cracking under fretting fatigue: Damage prediction under multiaxial fatigue

2002 ◽  
Vol 37 (6) ◽  
pp. 519-533 ◽  
Author(s):  
M-C Dubourg ◽  
Y Berthier ◽  
L Vincent
Keyword(s):  
Crack Initiation ◽  
Prediction Models ◽  
Crack Nucleation ◽  
Fretting Fatigue ◽  
Multiaxial Fatigue ◽  
Stage I ◽  
Fretting Wear ◽  
Stage Ii ◽  
Contact Conditions ◽  
Damage Prediction

Fretting is one of the plagues of modern industry. It occurs whenever a junction between components is subjected to cyclic sliding, with small relative displacements at the interface of the contacting surfaces. Further cyclic bulk stresses may be superimposed on to one or both components. The investigation of fretting wear and fretting fatigue started in the early 1970s. It is responsible for premature fatigue failures and often limits the life of a component. Crack initiation and growth under fretting contact conditions have been investigated. The fretting map concepts allow the first degradation responses of the material—no degradation, cracking and wear—to be related to a fretting regime with its corresponding local contact conditions during fretting tests. The fretting fatigue prediction models have been developed and compared to experiments conducted either on metallic or photoelastic materials. A special emphasis has been directed towards crack nucleation and early growth during stage I, the stage I-stage II transition and stage II crack growth (crack initiation sites, orientation, growth path, formation of a branch, growth mechanism). The analysis of the different stages that comprise the crack lifetime has been carried out in order to understand the effects of diverse parameters that are thought to influence the fretting damage.

scholarly journals Fretting Wear Behavior and Photoelectron Spectroscopy (XPS) Analysis of a Ti/TiN Multilayer Film Deposited on Depleted Uranium

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1538 ◽  
Author(s):  
Shengfa Zhu ◽  
Yanping Wu ◽  
Zhengyang Li ◽  
Liping Fang ◽  
Anyi Yin ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Photoelectron Spectroscopy ◽  
Multilayer Film ◽  
Wear Behavior ◽  
Normal Load ◽  
Depleted Uranium ◽  
Fretting Wear ◽  
Partial Slip ◽  
Xps Analysis ◽  
Slip Region

Depleted uranium has been widely applied in nuclear energy fields. However, its poor corrosion and wear resistance restrict its applications. A titanium/titanium nitride (Ti/TiN) multilayer film was deposited on a uranium surface to improve its fretting wear resistance. Fretting wear tests were carried out using a pin-on-disc configuration. The fretting behaviors of uranium and the Ti/TiN film were investigated under different normal loads. With the normal load increasing, the mode of fretting wear gradually transformed from slip region (SR) to mixed fretting region (MFR) and then to partial slip region (PSR). It is illustrated that the normal load had an obvious effect on the fretting wear behavior. The friction coefficients of both uranium and Ti/TiN multilayer film decreased with the increase of the normal load. In SR, the main wear mechanisms were delamination and abrasion for uncoated uranium, and delamination and oxidation for uranium coated with the Ti/TiN multilayer film. Photoelectron spectroscopy (XPS) analysis also showed that the Ti/TiN coating was oxidized and formed TiO2 during fretting wear. The wear depth of naked uranium was much greater than that of coated uranium, which demonstrated that the Ti/TiN multilayer film could effectively improve the wear properties of uranium.

scholarly journals The Evolution of Fretting Wear Behavior and Damage Mechanism in Alloy 690TT with Cycle Number

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2417 ◽  
Author(s):  
Long Xin ◽  
Yongming Han ◽  
Ligong Ling ◽  
Weidong Zhang ◽  
Yonghao Lu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Laser Scanning ◽  
Wear Behavior ◽  
Ion Beam ◽  
Fatigue Cracking ◽  
Damage Mechanism ◽  
Fretting Wear ◽  
Partial Slip ◽  
Stick Slip ◽  
Cycle Number

The evolution of fretting wear behavior and damage mechanism in Alloy 690TT with cycle number was investigated via laser scanning confocal microscopy (LSCM), scanning electron microscopy (SEM), focus ion beam (FIB), and transmission electron microscopy (TEM). The results showed that the fretting running status underwent a transition from partial slip and mixed stick-slip to final gross slip with the transformation of Ft–D curves from the ellipse to the parallelogram. The coefficient of friction (COF) experienced three drops throughout the fretting process, which indicated the transformation from high-friction wear to low-friction wear. The first drop was due to the transition from two-body to three-body contact. The second and third drops were mainly related to the evolution of the glaze layer from a localized distribution to completely covering the whole contact surface. The competition between fretting induced fatigue cracking (FIF) and fretting induced wear (FIW) ran through the entire fretting wear process. Before the 1.2 × 104th cycle, the fatigue crack growth was faster than wear, and FIF won the competition. As the fretting cycle continued to increase, the wear velocity was obviously faster than that of FIF, which indicated that FIW defeated FIF. The tribologically transformed structure (TTS) participated in the competition between FIF and FIW. The gain boundaries and dislocations in the TTS were a suitable pathway for crack initiation and propagation and oxygen permeation.

Rotational Fretting Wear of Ion Nitrided Medium Carbon Steel

2010 ◽  
Vol 97-101 ◽  
pp. 1532-1541
Author(s):  
J. Luo ◽  
Y.D. Wang ◽  
C. Song ◽  
J.L. Mo ◽  
Min Hao Zhu
Keyword(s):  
Carbon Steel ◽  
Friction Coefficient ◽  
Normal Load ◽  
Angular Displacement ◽  
Nitrided Layer ◽  
High Hardness ◽  
Fretting Wear ◽  
Partial Slip ◽  
Slip Regime ◽  
Substrate Steel

The nitrided layer on the surface of LZ50 (0.50% C) carbon steel was prepared by ion nitriding technique and its characterizations were detected by using Vickers hardness tester, profilometer, scanning electric microscope (SEM), optical microscope (OM) and X-ray diffraction (XRD). Rotational fretting is one of basic running modes in contact configuration of ball-on-flat, to which was paid little attention. The rotational fretting wear behaviors of the nitrided layer and its substrate steel were comparatively studied in dry condition under varied angular displacement amplitudes (θ) in range of 0.125º-1º, imposed normal load (Fn) of 20 N and a constant rotational speed of 0.2º/s. The experimental results showed that the nitrided layer presented rough and porous surface and high hardness was mainly consist of ε-Fe2-3N and γ׳-Fe4N phases. Compared with the substrate steel, the nitrided layer had a significant effect on reducing the friction coefficient and improving the fretting wear resistance, though the nitrided layer almost didn’t change the fretting running regimes of the substrate steel. In the partial slip regime, lower friction coefficients and slight damage appeared for the nitrided layer due to the coordination of elastic deformation of contact zones. In the slip regime, the friction coefficient of the nitrided layer was lower than that of the substrate in the initial stage as a result of the preventing plastic deformation by its high hardness surface. The rotational fretting wear mechanism of the nitrided layer in the slip regime was mainly identified as abrasive wear, oxidative wear and delamination. As a result, the nitrided layer presented a better capability for alleviating rotational fretting wear.

Insights into the fatigue cracking of Alloy 690TT subjected to fretting wear under partial slip conditions

2020 ◽  
Vol 159 ◽  
pp. 110040 ◽  
Author(s):  
Long Xin ◽  
Qian Huang ◽  
Yongming Han ◽  
Hongchao Ji ◽  
Yonghao Lu ◽  
...  
Keyword(s):  
Fatigue Cracking ◽  
Fretting Wear ◽  
Partial Slip ◽  
Slip Conditions
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