TLA and wear quantification of an aluminium–silicon–copper alloy for the car industry (original) (raw)
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Tribology in industry, 2023
The tendency to use aluminum alloys to replace conventional gray cast irons (GCI) materials in engine blocks of passenger cars is gaining more and more importance driven by reduction of engine weight to achieve expectation for lowering fuel consumption and CO₂ emissions. In this work the tribological effect of new produced aluminum engine cylinder liner is compared with the conventional cast iron the cylinder bore for friction, lubrication and wearresistance. Their tribological performance was evaluated through a reciprocating tribometer, using steel ball (100 CR6) on an aluminum and cast iron Diesel engine cylinder liners with 5W-40 engine oil to investigate their wear and friction behavior in boundary lubrication regime. There is a great effect of the roughness of machining marks (honing) on the surface of the liner. Although the same honing type was applied on both liner sleeves, aluminum liner presented less wear track, less roughness smoother surface related to cast iron liner. Repeated friction tests presented almost similar coefficient of friction data. Friction and wear comparison is well determined and the rubbed surfaces as well as all additives were analyzed through 2D-3D roughness digital optical microscopy, SEM-EDX analysis.
Testing friction and wear of the tribosystem piston ring and cylinder liner outside of engines
Tribotest, 2008
An OEM-driven working group started in January 2004 to elaborate the philosophies, concepts and test procedures for testing piston ring and cylinder liner materials as well as engine oils outside of engines using the SRV (abbreviation for German: 'Schwingung, Reibung, Verschleiß'; in English: 'Oscillation, Friction, Wear') test equipment. The different SRV test philosophies in use by OEMs are compiled. The working group focuses on (i) ASTM fuel economy sequence by ageing oils; (ii) friction and wear in the top-dead-centre region under mixed/boundary lubrication; (iii) extreme pressure load under mixed/boundary lubrication; and (iv) hydrodynamic friction. Tribological test results and precision data are presented.
Industrial Lubrication and Tribology, 2003
The test procedure for characterizing the tribological behavior of lubricants and materials for the system “piston ring/cylinder liner” outside of engines is now operational and validated. The test parameters presented in this paper (FN=50 N; v=0.3 m/s, s=24 km) may act only as an indicator and should be used to the tasks regarded. It allows the check prior expensive engine testing, if a tribomaterial, tribocouple or new lubricant will reach a satisfactory engine performance. The introduction of piston ring segments and cylinder liner as specimen into the test rig as well as the volumetric wear determined by means of stylus profilometry represented a big step forward in order to increase the transferability of “tribotests” to engine tests on an acceptable level.
Study on wear properties of aluminium–silicon piston alloy
Low expansion aluminium-silicon eutectic alloys are cast to produce most of the automotive pistons. The structure and properties of these alloys are very much dependent on the cooling rate, composition, modification and heat treatment operations. In this study, locally available automotive 'scrap pistons' were used as basic raw materials and a natural gas fired crucible furnace was used for melting purpose. The wear behaviour of both as-cast and heat treated specimens were studied under dry sliding conditions at room temperature using a pinon-disc type wear testing apparatus. The extent of wear damage and the type of wear were investigated by means of weight loss measurement and optical microscopy techniques. The full heat treatment showed a great influence on the wear properties of the aluminiumsilicon piston alloy as it reduced the wear rate of the specimens. The exceptional high tensile strength and hardness were attributed to the heat treatment condition with decrease in ductility. Significant changes in structure were also observed to occur specially in the primary and eutectic silicon phases. Some of the results of this study can be recommended for tribological use of this alloy in manufacturing automobile spare parts. # 2001 Published by Elsevier Science B.V.
Tribology International, 2017
A rotational tribometer as well as a corresponding test method for measuring friction and wear under pure sliding conditions were developed for the purpose of single parameter analysis of piston ring to cylinder liner contacts. Using this rotational tribometer and applying the developed test method, such analyses were carried out at a high level of precision and under close-to-engine conditions within a wide range of relevant operation parameters of internal combustion engines. In order to validate the test method, the friction and wear of a compression piston ring running against a honed cylinder liner were studied. In this paper, the influence of the test parameters contact temperature, ring load, test duration and sliding speed on the friction and wear behavior of a hard chrome-plated piston ring against a thermally sprayed, iron-based cylinder liner coating (NANOSLIDE ®) was analyzed. The friction and wear study at low, medium and high combustion chamber pressures, low to high sliding speeds as well as at moderate to high contact temperatures will be discussed exemplarily. The obtained wear results show very good correlation to engine durability tests.
Friction, 2016
The friction coefficient, wear rate, and wear coefficient of the aluminum metal surface were measured at room temperature (≈300 K) with a pin-on-disk machine at a fixed load of 196.2 N. Two different testing configurations were adopted: (1) aluminum pin vs. Helix oil-on-steel disk (AHS) and (2) aluminum pin vs. 10% Polytron plus 90% helix oil-on-steel disk (APS). In the AHS configuration, the wear of the aluminum surface was found to be approximately 70 μm; however, in the APS configuration the wear dropped to 20 μm, revealing a marked decrement of one-third of the wear of aluminum. The volume wear rate of the metal in the unaided Helix oil was estimated to be 1.28×10–3 mm3/min. The additive minimized the volume wear rate of the aluminum metal by orders of magnitude to 6.08×10–5 mm3/min. Similarly, the wear coefficient of the aluminum pin, calculated in the AHS configuration, rendered a value of 1.27×10–10 m2/N. In the APS configuration, the same parameter was 4.22×10–11 m2/N, that ...
Corrosive Wear Behavior of Commercial Aluminium Engine Block and Piston in 3.5% NaCl Solution
The tribological performance of commercially used aluminium engine block and piston was evaluated at ambient condi-tions under dry and corrosive environment using a pin-on-disc with an applied load of 20 N at sliding velocity of 0.29 ms-1 and with varying sliding distance ranging from 260 m - 4200 m. The worn surfaces were characterized by optical micro-scope, SEM and EDX analyzer. The results showed that the nature of the wear rate was similar in both environments for both alloys which initially increases afterwards decreases to more or less a constant value. Moreover, for the block and piston alloys, the wear rate in corrosive environment was significantly higher than the dry condition. Due to the presence of Ni, higher percentage of Mg and lower percentage of Fe, the aluminium piston alloy showed higher wear performance than that of the block alloy.
TRIBOLOGICAL PROPERTIES OF PISTON‐CYLINDER SET IN INTERNAL COMBUSTION ENGINES
This paper presents a wear process analysis of piston‐cylinder set in internal combustion engines.Piston mechanism is a very important factor in the proper lubrication of the engine, but also a potential cause of increased consumption of oil. There are very important kinematic ‐ tribological properties of piston mechanisms in this regard. From the point of reliability and functionality, critical parts of this circuit are the piston rings. Wear is most pronounced in the first piston ring, since it is exposed to the highest pressure and temperature, as well as the direct impact of fuel and combustion products. The intensity of wear of piston ‐ cylinder set depends on many factors, but the most influential ones are: construction, materials used for the production of the parts of this assembly, production technology and conditions of use.
Archive of Mechanical Engineering, 2010
Rising technical standards of customers, legal requirements and the trend to minimize maintenance effort raise the thermal, mechanical and tribological loads on components of combustion engines. In this regard, emphasis is laid on improving the piston ring -cylinder liner tribosystem, one with the highest energy losses. An efficient performance has to be guaranteed during its lifetime. Tribological investigations could be carried out on engine test benches, but they are highly cost-intensive and time-consuming. Therefore, a damage-equivalent test methodology was developed with the analogous tribological model, "ring-on-liner". The research was carried out under two characteristic operating conditions. One with a "standard" operating system, modelled in line with ideal lubrication conditions, and the other "extreme abrasive" operating system, typical to a system running on a lubricant contaminated by abrasive particles. To optimize the tribological loading capacity of the cylinder liner, with focus on these two operating conditions, numerous nitride coatings have been investigated. The key aspects being seizure resistance, running-in characteristics and long term wear behaviour.