Development of a Model Test System for a Piston Ring/Cylinder Liner-Contact with Focus on Near-to-Application Seizure Behaviour

Abstract

Physical simulations of tribo contacts in internal combustion engines can act as a supporting tool to match upcoming guidelines and emission restrictions. In particular, the scuffing resistance of the contact between the piston ring and cylinder liner suffers under decreasing oil viscosity and limitation of antiwear additives. This paper aims to provide an experimental method to simulate the scuffing of the piston ring/cylinder liner-contact and to validate this method with real engine parts and the literature from engine tests. The experimental methodology uses a linear tribometer TE77 to test specimens from original piston rings and liners under reciprocating motion. Additionally, the ring specimen is given the opportunity to perform secondary movements (ring twisting, ring turning) and to run under deficient lubrication conditions similar to the engine. A specially designed test strategy enables the reproducible creation of seizure of the tribosystem. The seizure resistance of two engine oils, tested for validation, correlates with the known engine performance. Therefore, the model test system can be seen as a reproducible tool for simulating seizure of a ring/liner-system, showing similar trends and wear mechanisms as in an engine. Surface analysis depicts similarities between the scuffed surfaces of an engine and the model and discusses the origin of seizure based on the model specimens together with the relevant literature.

Advanced Tribological Characterization of DLC Coatings Produced by Ne-HiPIMS for the Application on the Piston Rings of Internal Combustion Engines

“…Since the objective of this work was to study the tribological properties of the coatings, it was necessary to use a base lubricating oil, free of additives such as friction modifiers, for a better understanding of the real role of the coatings. In addition, although the contact between the piston ring and cylinder liner is mostly governed by hydrodynamic and mixed lubrication regimes in the internal combustion engines [20], when the piston ring hits the top dead center of the stroke, the contact is in the boundary lubrication regime where the role of the coatings matters [21]. Therefore, Polyalphaolefin (PAO) 8 base oil was chosen as the lubricating oil for this study because it is used as the base oil for some of the commercial engine oils [22].…”

Influence of 1-Ethyl-3-methylimidazolium Diethylphosphate Ionic Liquid on the Performance of Eu- and Gd-Doped Diamond-like Carbon Coatings

“…Additionally, it has been extensively researched and serves as a reference in numerous scientific studies [2]. The utilization of this base lubricating oil, both in its pure form and in combination with additives, allowed for a comprehensive analysis of the coatings' performance throughout various lubrication conditions [40][41][42]. For the purposes of this research, the IL known as 1-Ethyl-3-methylimidazolium diethylphosphate was employed.…”

Tribological Behavior of Doped DLC Coatings in the Presence of Ionic Liquid Additive under Different Lubrication Regimes

“…The hydrodynamic and mixed lubrication regimes in internal combustion engines dominate the contact between the piston ring and cylinder liner for the most part, but a boundary lubrication regime is frequently found at the top dead center of the stroke, which necessitates the implementation of coatings. Polyalphaolefin (PAO) 8 was selected as the base lubricating oil because it serves as the base oil for various commercial engines [34,37,38]. Trihexyltetradecylphosphonium bis (2-ethylhexyl) phosphate [ P 66614 ] [DEHP] ionic liquid was used in this study.…”