Reproducing automotive engine scuffing using a lubricated reciprocating contact

Kamps, T.J.; Walker, J. C. F.; Wood, R.J.K.; Lee, P.M.; Plint, A.G.

doi:10.1016/j.wear.2014.12.045

Cited by 31 publications

(20 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mild scuffing presents as localised damage which reduces the surface roughness, crucially it is possible that the contact might recover from this condition [17]. Severe scuffing however is irrecoverable and results in gross surface damage and a dramatic increase in roughness [12] due to significant adhesive wear of the cast iron surface causing catastrophic damage.…”

Section: Discussionmentioning

confidence: 99%

“…Instantaneous high speed friction force and contact potential data was captured in bursts of 10,000 samples at 10 kHz, in order to determine the location of surface damage and lubricant film breakdown along the stroke. Mild scuffing was indicated by an increase in excess of 100% of the RMS friction force at the stroke reversal positions [17].…”

Section: Methodsmentioning

confidence: 99%

“…This is challenging as scuffing is a complex multi-stage process with many interdependent variables [9], and the transition from mild wear to seizure occurs in a couple of minutes [10]. Acoustic emissions [11]- [13], electrostatic sensors [9], [14], [15] and high speed friction data [16], [17] have been used to detect the onset and progression of scuffing. The techniques have enabled scuffing wear to be classified into two stages, mild and severe scuffing, which has allowed possible mechanisms to be proposed.…”

Section: Introductionmentioning

confidence: 99%

“…However the nodules do not act as stress raisers during a contact overload [23], [27]. The present study is concerned with determining the influence that graphite morphology has on the scuffing behaviour of an EN-GJS 400-15 spheroidal cast iron, compared to a flake cast iron structure [17] in a simulated piston ring and cylinder liner contact. Observing the start of mild scuffing using instantaneous friction force measurements allows interruption of sliding at the critical onset of scuffing, facilitating observation of the mechanisms leading to catastrophic adhesive wear through a combination of optical profilometery and focused ion beam/scanning electron microscopy.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Scuffing mechanisms of EN-GJS 400-15 spheroidal graphite cast iron against a 52100 bearing steel in a PAO lubricated reciprocating contact

Kamps

Walker

Wood

et al. 2017

Wear

Self Cite

View full text Add to dashboard Cite

Scuffing of the automotive piston ring on liner contact is likely to increase due to engine downsizing and the use of low viscosity engine oils to achieve greater fuel efficiency. This work investigated the scuffing mechanism of EN-GJS 400-15 spheroidal graphite cast iron caused by reciprocating sliding of a 52100 roller bearing element lubricated with PAO base oil.The contact was conditioned at 100N and 15 Hz over a stroke of 25 mm at 180 o C. Subsequently the load was incremented in 100 N/min steps at 5 minute intervals until severe scuffing occurred, indicated by a rapid rise in the average friction coefficient. High speed friction was used to determine the onset of mild and severe scuffing. Stylus and 3D optical profilometery revealed that mild scuffing produced a smooth surface with small cracks compared to the severe scuffed surface which contained adhesive wear craters of 40 µm in depth. Focused ion beam cross-sections of the mild scuffed surface and EDS analysis of the microstructure indicated that cracks were initiated by dross inclusions with a similar morphology to flake graphite. The transition to severe scuffing occurred at 700N when crack networks facilitated adhesive transfer of cast iron material to the counter-surface.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Scuffing mechanisms of EN-GJS 400-15 spheroidal graphite cast iron against a 52100 bearing steel in a PAO lubricated reciprocating contact

Kamps

Walker

Wood

et al. 2017

Wear

Self Cite

View full text Add to dashboard Cite

show abstract

“…During a wear transition, such as scuffing for example, contact surfaces experience alteration in the form of plastic deformation or material removal [6][7][8]. The wear severity determines whether the contact can return to its previous wear regime or whether it has been significantly modified making the wear transition permanent [9].…”

Section: Introductionmentioning

confidence: 99%

In situ stylus profilometer for a high frequency reciprocating tribometer

Kamps

Walker

Plint³

2017

Surf. Topogr.: Metrol. Prop.

View full text Add to dashboard Cite

Measuring the friction and wear characteristics of a tribological contact is essential to gaining a detailed understanding of its performance and predicted life. Wear rate and friction coefficient measurements are obtained from instrumented benchtop tribometers designed to replicate specific tribological contacts. Due to the difficulty of measuring wear in situ, measurements are typically made before and after an experiment. The wear rate must be assumed to be linear for it to be used to predict product life, however this is assumption can hide changes occurring during an experiment which indicate wear transitions. This paper details the design and validation of an in situ stylus profilometer for a reciprocating sliding tribometer to provide an insight into the wear transitions occurring during dry sliding of 52100 bearing steel against graphitic flake cast iron. The profilometer's performance was validated using ground roughness standards and the accuracy found to be approximately 110nm. Incubation, run-in and steady state wear regimes were identified by the profilometer and corroborated with friction coefficient data, providing an enhanced understanding of the tribological contact behaviour.

show abstract