Test Modes for Establishing the Tribological Profile under Slip-Rolling

Patzer, Gregor; Woydt, Mathias; Shah, Raj; Miller, Curtis; Iaccarino, Philip

doi:10.3390/lubricants8050059

Cited by 10 publications

(4 citation statements)

References 11 publications

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“…where r w is a wire radius, mm and α is an angle of the segment, degree. The volumetric (R v ) and mass wear rates (R m ) are calculated by the following equations [53,54]:…”

Section: Characterization Of the Samples Wear Rate And Discharge Gapmentioning

confidence: 99%

Wire Tool Electrode Behavior and Wear under Discharge Pulses

et al. 2020

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This work is devoted to researching the tool electrode behavior and wear under discharge pulses at electrical discharge machining. The experiments were conducted on the workpieces of 12Kh18N10T (AISI 321) chrome-nickel anti-corrosion steel and D16 (AA 2024) duralumin by a 0.25-mm-diameter CuZn35 brass tool in a deionized water medium. The developed diagnostic and monitoring mean based on acoustic emission registered the oscillations accompanying machining at 4–8 kHz. The obtained workpiece and non-profiled tool surfaces were investigated by optical and scanning electron microscopy. Calculated volumetric and mass removal rates showed the difference in the character of wear at roughing and finishing. It was shown that interaction between material components in anti-corrosion steel machining had an explosive character between Zn of brass and Ni of steel at a micron level and formed multiple craters of 30–100 µm. The secondary structure and topology of worn tool surfaces were caused by material sublimation, chemical interaction between material components at high heat (10,000 °C), explosive deposition of the secondary structure. Acoustic diagnostics adequately registered the character of interaction. The observed phenomena at the submicron level and microstructure of the obtained surfaces provide grounding on the nature of material interactions and electrical erosion wear fundamentals.

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“…where r w is a wire radius, mm and α is an angle of the segment, degree. The volumetric (R v ) and mass wear rates (R m ) are calculated by the following equations [53,54]:…”

Section: Characterization Of the Samples Wear Rate And Discharge Gapmentioning

confidence: 99%

Wire Tool Electrode Behavior and Wear under Discharge Pulses

et al. 2020

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“…The steady-state friction coefficient m steady represents the arithmetic mean of the last 100 measuring points of all testings of a coating-lubricant combination (Figure 2). The 2dT represents a proven test method for function and application-oriented testing on tribosystems under sliding, rolling and rolling stress where under variable load and adjustable slip speeds, dynamic contact situations and processes can be mapped at high speeds and temperatures over longer periods (Patzer et al, 2020). An initial screening was carried out on the 2dT to investigate the tribological effectiveness of the developed coatings in highly loaded contacts subject to slip (Figure 3).…”

Section: Tribological Testingmentioning

confidence: 99%

Tribological behavior of different doped ta-C coatings for slip-rolling contacts with high hertzian contact pressure

Polzer

Bartz

Rothammer

et al. 2023

ILT

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Purpose The curved and tribologically highly stressed surfaces of bearing components pose a major challenge for steel alloys or tribological resistant coatings like tetrahedral amorphous carbon (ta-C) coatings which in particular have an increased risk of delamination due to the significantly increased residual stresses. A possibility to prevent coating failure is the use of dopants while maintaining or even increasing tribological properties. This study aims to compare the tribological behavior of several doped diamond-like-carbon coatings with an undoped ta-C coating under varying slip conditions and Hertzian pressure up to 1800 MPa. Design/methodology/approach For this purpose, the tribological behavior was studied using of a ball-on-disc tribometer and a two-disc test rig under mixed/boundary conditions. The tests were conducted with coated specimens against uncoated 100Cr6 steel. Additionally, the influence of lubrication additives was studied due to the use of two fully formulated PAO-based oils, one without and one with molybdenum containing additives. The friction was measured in situ, and the wear was analyzed trough laser scanning microscopy and tactile measurement. Findings It was shown that the use of doped ta-C coatings exhibited a tendency for a more favorable tribological behavior compared to undoped ta-C coatings, with no general dependence on the lubricants used. The use of the most suitable coatings reduced the wear of the steel counter-body considerably. Originality/value To the best of the authors’ knowledge, this is the first approach of testing the tribological behavior of these doped ta-C coatings, developed for friction efficiency, in dependency on lubrication additives under the given load collective. The approach is relevant to determine whether the friction reduction and the wear inhibition of these coatings are suitable for higher contact pressures and load cycles. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2022-0336/

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“…For tribological experiments under rolling-sliding conditions, a two-disc tribometer (2DT) can be used for a variety of materials and lubricants [42][43][44][45]. The 2DT is applicable for the characterization of tribological systems in a wide range, from pure sliding to various slip conditions to pure rolling.…”

Section: Introductionmentioning

confidence: 99%

“…With regard to tooth flanks or rolling bearings, findings from tests in 2DTs are more transferable than those from the ball-on-disc tests usually performed, and allow the possibility of high Hertzian contact stresses. While the investigations mainly focus on the testing of tribologically effective thin coatings or bearing steel under oil lubrication conditions, the two-disc test rig is also a suitable test method for dry lubrication conditions [42][43][44]46,47].…”

Section: Introductionmentioning

confidence: 99%

Effects of Nitrogen Modification of Porous PVD–MoS2 Coatings on the Tribological Behavior under Rolling–Sliding Conditions in Vacuum

et al. 2023

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In order to improve the tribological performance of PVD–MoS2 coatings, which are frequently used as a solid lubricant for operating in challenging environments, e.g., in a vacuum, they can be modified with nitrogen. This work evaluates the tribological behavior and a possible compaction occurring during the initial tribological load in the rolling contact for pure and nitrogen-modified PVD–MoS2 coatings in a vacuum. Short-running tests (1000 cycles) of coated steel discs paired with uncoated steel discs made from 100Cr6 (1.3505, AISI 52100) were conducted on a two-disc tribometer. The slide-to-roll ratio of 10.5% was kept constant, while the load was varied in two steps from 1.1 GPa to 1.6 GPa. Subsequently, a comparison was made between the worn and the pristine coatings by means of nanoindentation and an optical analysis of the wear track. The formation of a load-bearing solid lubrication was achieved for both MoS2-variants. The main differences affected the material transfer and wear mechanisms. The worn coatings reached a similar wear coefficient of 4 × 10−6 mm3N−1m−1 and a possible compaction of the coatings was found, indicated through an increased indentation hardness (for MoS2 1158% and MoS2:N 96% at a 1.1 GPa load). The assumed tribological mechanism changed with nitrogen modification, but scales with increasing load. The nitrogen-modified MoS2 coating showed less compaction than pure MoS2, while the frictional behavior was improved by a 17°% reduction of the coefficient of friction.

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Test Modes for Establishing the Tribological Profile under Slip-Rolling

Cited by 10 publications

References 11 publications

Wire Tool Electrode Behavior and Wear under Discharge Pulses

Wire Tool Electrode Behavior and Wear under Discharge Pulses

Tribological behavior of different doped ta-C coatings for slip-rolling contacts with high hertzian contact pressure

Effects of Nitrogen Modification of Porous PVD–MoS2 Coatings on the Tribological Behavior under Rolling–Sliding Conditions in Vacuum

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