The Impact of Surface Integrity by Hard Turning vs. Grinding on Rolling Contact Fatigue

2007 ◽  
Author(s):  
A. W. Warren ◽  
Y. B. Guo
Keyword(s):  
Acoustic Emission ◽  
Surface Integrity ◽  
Hard Turning ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Rolling Contact ◽  
Polished Surface ◽  
Emission Signal ◽  
The Impact

Hard turning and grinding are finishing processes for the manufacture of precision components such as bearings, gears, and cams. However, the effects of distinct surface integrity by hard turning vs. grinding on rolling contact life are poorly understood. Four representative surface types were prepared: as-turned, as-ground, turned and polished, and ground and polished. Surface integrity was characterized by surface topography, microstructure, and micro/nanohardness. Fatigue tests were performed with an acoustic emission sensor and the signal processing software. The amplitude of acoustic emission signal is the most stable and sensitive signal to fatigue failure. The turned surface may have a longer life (>84%) than the ground one with equivalent surface finish.

Acoustic Emission Monitoring for Rolling Contact Fatigue Damage of Machined Components by Hard Turning vs. Grinding

2007 ◽  
Author(s):  
A. W. Warren ◽  
Y. B. Guo
Keyword(s):  
Shear Stress ◽  
Acoustic Emission ◽  
Fatigue Damage ◽  
Surface Integrity ◽  
Rolling Contact Fatigue ◽  
Real Life ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Second Phase ◽  
Surface Cracks

The fundamental knowledge of fatigue damage mechanism is necessary for understanding manufacturing process effects. However, the artificial defects on the test samples in traditional fatigue tests will change the surface integrity and therefore may not reflect the nature of fatigue damage. This paper studies the fatigue damage resulting from real-life rolling contact tests and finite element analysis of AISI 52100 steel and identifies the possible mechanisms for fatigue failure in the presence of process induced surface integrity. Rolling contact fatigue damage was real-time monitored using an acoustic emission (AE) sensor. Surface and subsurface fatigue damage of the samples was then characterized using optical and scanning electron microscopy (SEM) and surface profiling. The results suggest that shear stress induced Mode II crack is the dominant fatigue mechanism. Two types of subsurface cracks were observed: main cracks that propagate parallel to the surface due to subsurface shear stress induced fracture/debonding of inclusions or second phase particles. Shear stress induced surface cracks propagate at shallow angles (∼35°) from the surface. Branching cracks eventually form and connect the main crack to surface. The formation of main cracks and surface cracks may be parallel processes, and spalling occurs as a combined effect of the main, surface, and branching cracks. The relationship between AE signals and fatigue damage was been established.

Fatigue Prediction of Thin Hard Coatings on the Steel Races of Hybrid Bearings Used in High Speed Machine Tool Spindles

1998 ◽  
Vol 120 (4) ◽  
pp. 835-842 ◽  
Author(s):  
K.-D. Bouzakis ◽  
N. Vidakis ◽  
S. Mitsi
Keyword(s):  
High Speed ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fem Simulation ◽  
Bearing Steel ◽  
Fatigue Tests ◽  
Rolling Contact ◽  
Hard Coatings ◽  
Long Duration ◽  
The Impact

The rotational speed requirements of high speed spindles led to the development of angular contact hybrid bearings with ceramic balls and PVD coated steel races. The present paper describes the determination and verification of critical coating fatigue stresses as well as their application in coating fatigue calculations of hybrid bearing steel races. The fatigue limits of low temperature deposited PVD coatings were determined by the application of the impact test and its FEM simulation and validated through their successful application to the prediction of coating life in rolling contact fatigue tests of coated specimens. Furthermore, a computer program that performs the quasi-static simulation of bearing operation yields the necessary kinematic and dynamic parameters for a FEM simulation of the stress field occurring in coated rings. For the investigated bearings, an adequate fatigue performance of their coated races was computationally exhibited. The PVD coated hybrid bearings illustrated the predicted behavior in long duration tests, conducted in full scale test rigs.

Influence on Tribological Behavior of PEEK Composite Film Layer on PEEK-PTFE Bearings with Artificial Defect in Dry Condition

2021 ◽  
Vol 904 ◽  
pp. 243-249
Author(s):  
Hitonobu Koike ◽  
Koshiro Mizobe ◽  
Katsuyuki Kida
Keyword(s):  
Composite Film ◽  
Tribological Behavior ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Rolling Contact ◽  
Artificial Defect ◽  
Peek Composite ◽  
Film Layer ◽  
Number Of Cycles

In order to explore influence on tribological behavior of PEEK composite film layer in PEEK-PTFE composite radial alumina ball bearings, rolling contact fatigue tests were performed by using the PEEK bearing’s inner rings with the artificial defects in dry condition. When rotation speed and applied load were 600 rpm and 98 N, the number of cycles of the PEEK-PTFE bearings reached 1.0×107 fatigue cycles. The artificial defects with 0.02 mm depth on the raceway surface of the PEEK inner ring was covered with PEEK composite film accumulation.

Effect of PTFE Retainer on Friction Coefficient in Polymer Thrust Bearings under Dry Contact

2013 ◽  
Vol 683 ◽  
pp. 90-93 ◽  
Author(s):  
Koshiro Mizobe ◽  
Takashi Honda ◽  
Hitonobu Koike ◽  
Edson Costa Santos ◽  
Yuji Kashima ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Rolling Contact ◽  
Low Friction ◽  
Friction Forces ◽  
Thrust Bearings ◽  
Dry Contact

Polyetheretherketone (PEEK) is a tough semi-crystalline thermoplastic polymer with excellent mechanical properties. While abilities of polyphenylenesulfide (PPS) are similar to PEEK, former material cost was lower than later. Polytetrafluoroethylene (PTFE) is well known because of its low friction coefficient and self lubrication ability. The objective of this study is to observe the friction coefficient of hybrid bearings, PTFE retainer sandwiched with PPS-races or PEEK-races. Rolling contact fatigue tests were performed and in situ friction forces wear measured. It is concluded that the PTFE retainer reduced friction coefficient.

Experimental Investigations Upon Fatigue Life of Circular Contacts With Transversal Furrow

2005 ◽  
Author(s):  
Delia F. Cerlinca ◽  
Emanuel N. Diaconescu
Keyword(s):  
Fatigue Life ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Geometric Parameters ◽  
Rolling Contact ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Contact Fatigue Life

Rolling contact fatigue depends essentially on both surface and subsurface populations of defects. First, this paper describes experimental results obtained in rolling contact fatigue tests in the presence of a furrow oriented transversally to the race-way. Then an attempt to predict theoretically the effect of geometric parameters of the furrow upon contact fatigue life is described.

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