The evolution of tribolayers during high temperature sliding wear

Rynio, C.; Hattendorf, Heike; Klöwer, J.; Eggeler, Gunther

doi:10.1016/j.wear.2014.03.007

Cited by 103 publications

(33 citation statements)

References 40 publications

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“…In this experimental study, the lowest value of normal load was chosen as 20 N. At the beginning of the test, for the chosen pin-on-disc configuration at a load of 20 N, a contact pressure of more than 1000 MPa occurs between the hemispherical shaped pin and the disc. As the test continues, this is appreciably reduced to a value of < 20 MPa, which has been reported in a valve and valve-seat contact in an engine [17]. However, with increasing power output expected from engines in the future, the demands on the components in tribological contact is also expected to be severe.…”

Section: Friction and Wear Testsmentioning

confidence: 80%

“…Tribological studies of a commonly used exhaust valve material, a Ni-based super alloy, have been carried out at elevated temperatures. Cast iron, as a valve-seat material, has been the subject of many studies as well, with favourable wear resistance and formation of wear protective films reported in [16][17]. An exhaustive experimental study on valve wear has identified ductile cast iron as a potential valve-seat material for exhaust valve applications [18].…”

Section: Introductionmentioning

confidence: 99%

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Effect of load on tribofilms at the contact interface under dry sliding conditions at 500 °C

Saleem

Wàňi

2018

Materialwissenschaft Werkst

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This paper presents a study of the effect of load on the retention of the tribofilms formed at the interface of a dry sliding contact between exhaust valve material, Nimonic alloy (N 80A) and valve‐seat material, ductile cast iron (GGG‐40), at a temperature of 500 °C. The role of tribofilms in influencing friction and wear behaviour at elevated temperature is highlighted. Reciprocating pin‐on‐disc experiments were conducted using a hemispherical shaped pin sliding against a flat disc at 20 Hz oscillating frequency, 2 mm stroke at loads of 20 N to 50 N. Low coefficient of friction, in the range of 0.13 to 0.15, was observed at loads up to 40 N whereas at a load of 50 N, the average coefficient of friction increased to 0.29. Optical and scanning electron micrographs with energy dispersive spectroscopy analysis indicate evidence of formation and retention of well compacted and strongly adhering tribofilms at loads up to 40 N. At 50 N, even though more abrasive wear is seen, initial deterioration and subsequent reforming of the tribofilms with increasing sliding time is observed. Overall, more wear was observed for the valve‐seat material as compared to the valve material. Raman spectroscopy primarily indicates the presence of hematite on the worn surfaces at loads of 20 N to 40 N, whereas magnetite presence is strongest at the highest load of 50 N. Increase in tribofilm hardness was observed with increase in contact load whereas the thickness of the tribofilm was not significantly affected by the contact load.

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Section: Friction and Wear Testsmentioning

confidence: 80%

Section: Introductionmentioning

confidence: 99%

Effect of load on tribofilms at the contact interface under dry sliding conditions at 500 °C

Saleem

Wàňi

2018

Materialwissenschaft Werkst

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“…Therefore sliding tests of 1.0050 steel at higher bulk temperatures primarily evaluated the wear resistance of the austenitic γ phase, while testing at RT did primarily test the ferritic/pearlitic microstructure. Interestingly, very few references treat the role of phase transformation in HT wear behaviour of Fe-based materials [24,30], but many publications treat the formation of mechanically mixed layers at high temperatures [17,31,32,33]. This lack of references can possibly be attributed to the difficulty in evaluating the real testing temperatures at the tribocontact between the counter bodies.…”

Section: Discussionmentioning

confidence: 99%

Experimental simulation of high temperature sliding contact of hot rolled steel

Torres

Varga

Widder

et al. 2016

Tribology International

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“…Even if the nanostructured layers show improved mechanical properties at room temperature, these will change as temperature is increased due to occurrence of recovery, recrystallisation and grain growth phenomena. In a recent study pertaining to the evolution of tribolayers at high temperatures, Rynio et al [23] investigated reciprocating sliding between a Ni-based superalloy and cast iron and analysed the resulting surface layers. They found the formation of a multilayer structure on the Ni-based superalloy consisting of an outermost oxide layer, a white layer, an ultrafine grain layer and a deformed layer but without grain refinement.…”

Section: Introductionmentioning

confidence: 99%