The study of tribological properties of laser-textured surface of 2024 aluminium alloy under boundary lubrication

AbstractLaser surface texturing (LST) has been proven to improve the tribological performance of machine elements. The micro-scale patterns manufactured by LST may act as lubricant reservoirs, thus supplying oil when encountering insufficient lubrication. However, not many studies have investigated the use of LST in the boundary lubrication regime, likely due to concerns of higher contact stresses that can occur with the increasing surface roughness. This study aims to examine the influence of LST on the fatigue lifetime of thrust rolling bearings under boundary lubrication. A series of periodic patterns were produced on the thrust rolling bearings, using two geometrically different designs, namely cross and dimple patterns. Base oil ISO VG 100 mixed with 0.05 wt% P of zinc dialkyldithiophosphate (ZDDP) was supplied. The bearings with cross patterns reduce the wear loss by two orders of magnitude. The patterns not only retain lubricant in the textured pockets but also enhance the formation of an anti-wear tribofilm. The tribofilm generation may be improved by the higher contact stresses that occur when using the textured surface. Therefore, in contrast to the negative concerns, the ball bearings with cross patterns were instead found to increase the fatigue life by a factor of three.

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Pengaruh Penambahan Minyak Kelapa dan Sawit Terhadap Sifat Fisik dan Tribologi Pelumas SAE 40

Jurnal METTEK ◽

10.24843/mettek.2019.v05.i01.p01 ◽

2019 ◽

Vol 5 (1) ◽

pp. 1

Author(s):

Dedison Gasni ◽

KM Abdul Razak ◽

Ahmad Ridwan ◽

Muhammad Arif

Keyword(s):

Fatty Acids ◽

Coefficient Of Friction ◽

Tribological Properties ◽

Palm Oil ◽

Boundary Lubrication ◽

Viscosity Index ◽

Coconut Oil ◽

High Viscosity ◽

Mineral Oil ◽

Lubricating Oil

Penelitian ini bertujuan untuk mengetahui efek dari penambahan minyak kelapa dan sawit terhadap sifat fisik dan tribologi pelumas SAE 40. Vegetabel oil, seperti; minyak kelapa dan sawit, memiliki nilai viskositas indek yang tinggi dan sifat pelumasan yang baik terutama didaerah boundary lubrication jika dibandingkan dengan mineral oil (SAE 40). Hal ini disebabkan karena vegetabel oil memiliki kandungan fatty acids yang tidak dimiliki oleh mineral oil. Keunggulan lain dari minyak kelapa dan sawit adanya sifat yang ramah lingkungan karena mudah terurai di alam dan dapat diperbaharui. Pada penelitian ini sifat yang baik dari minyak kelapa dan sawit ini akan dimanfaatkan sebagai zat aditif pada minyak pelumas SAE 40. Pengujian dilakukan terhadap sifat fisik dan tribology dengan penambahan 5%, 10%, 15%, dan 20% berat dari minyak kelapa dan sawit ke dalam minyak pelumas SAE 40. Pengujian sifat fisik terdiri dari pengukuran viskositas pada temperatur 400C dan 1000C dan viskositas index. Pengujian sifat tribologi untuk menentukan keausan dan koefisien gesek berdasarkan ASTM G99 dengan menggunakan alat uji pin on disk. Dari hasil pengujian diperoleh bahwa dengan penambahan minyak kelapa dan sawit kedalam minyak pelumas SAE 40 terjadi peningkatan viskositas indeks. Peningkatan viskositas indeks sebanyak 17% dengan penambahan 20% minyak sawit. Terjadi perubahan sifat tribologi dengan penambahan minyak sawit, berupa penurunan keausan dan nilai koefisien gesek dibandingkan dengan penambahan minyak kelapa. This study aims to determine the effect of coconut and palm oils as additives to physical and tribological properties of SAE 40 lubricating oil . Vegetable oils, such as; coconut oil and palm oil, have high viscosity index and good lubrication properties, especially in boundary lubrication compared to mineral oil. This is due to vegetable oil having fatty acids that are not owned by mineral oil. The advantages of coconut oil and palm oil are environmentally friendly properties because they are biodegradable and renewable. In this study, the good properties of coconut and palm oils will be used as additives in SAE 40 lubricating oil. Tests are carried out on the physical and tribological properties with the addition of 5%, 10%, 15%, and 20% by weight of coconut and palm oils into SAE 40 lubricating oil. Physical properties testing consists of measuring viscosity at temperatures of 400C and 1000C and viscosity index. The tribological test is to determine wear and coefficient of friction based on ASTM G99 using a pin on disc test equipment. From the test results, it was found that coconut and palm oils as additives into SAE 40 lubricating oil could increase in viscosity index. The increase of the viscosity index was 17% by adding 20% of palm oil. There was a change of tribological properties in the form of decreasing on the wear and the coefficient of friction with the addition of palm oil compare to addition of coconut oil.

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Comparative Study of Mechanical and Tribological Properties of Alumina Coatings Formed on 5754 Aluminium Alloy under Various Conditions

Surface Engineering and Applied Electrochemistry ◽

10.3103/s106837551805006x ◽

2018 ◽

Vol 54 (5) ◽

pp. 524-533

Author(s):

I. Kessentini ◽

S. Zouari ◽

A. Bakir ◽

M. Bargui

Keyword(s):

Comparative Study ◽

Aluminium Alloy ◽

Tribological Properties ◽

Alumina Coatings ◽

Mechanical And Tribological Properties

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Effect of Temperature on the Tribological Properties of Selected Thermoplastic Materials Cooperating with Aluminium Alloy

Materials ◽

10.3390/ma14237318 ◽

2021 ◽

Vol 14 (23) ◽

pp. 7318

Author(s):

Anita Ptak ◽

Paula Taciak ◽

Wojciech Wieleba

Keyword(s):

Aluminium Alloy ◽

Contact Pressure ◽

Tribological Properties ◽

Polymer Materials ◽

Effect Of Temperature ◽

Test Results ◽

Friction Process ◽

Before And After ◽

Pin On Disc ◽

Two Parameters

This article concerns the tribological properties of three selected polymer materials: polyamide PA6, polyethylene PE-HD and polyetheretherketone composite PEEK/BG during sliding against aluminium alloy EN AW-2017A in the presence of hydraulic oil HLP 68. The tests were carried out under contact pressure p of 3.5–11 MPa at ambient temperature T ranging from −20 °C to +20 °C. The dependence of kinetic friction coefficient μk on the two parameters was determined through tribological tests carried out using a pin-on-disc tribometer. A five-level central composite rotatable design (CCRD) was adopted for the experiment. All the test results were statistically analysed. The microhardness of the surface of the polymeric material was measured before and after the friction process. The surface was also examined under SEM. Temperature and contact pressure have been found to have a significant effect on the tribological properties of the tested sliding pairs. Relative to the applied friction conditions, the surfaces after friction showed rather heavy signs of wear.

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ESTIMATION OF TRIBOLOGICAL PROPERTIES OF SELECTED PLASTICS MATERIALS MANUFACTURED BY EXTRUSION AND 3D PRINTING

Tribologia ◽

10.5604/01.3001.0014.8330 ◽

2021 ◽

Vol 294 (6) ◽

pp. 7-12

Author(s):

Henryk Bąkowski ◽

Zbigniew Krzysiak

Keyword(s):

Wear Resistance ◽

3D Printing ◽

Aluminium Alloy ◽

Tribological Properties ◽

Dry Friction ◽

Tribological Characteristics ◽

3D Printer ◽

Reciprocating Motion ◽

Block System ◽

Materials Used

The following work presents the results of research about the assessment of tribological properties of plastics used as components in modes of transport. For this purpose, the wear resistance of materials used in 3D printing (PA6CF and ABS), and extrusion moulding (PA) were tested. The tribological research was carried out with the use of the T-05 tester in the roller-block system. The samples in the form of cuboids with a concave rounding of one wall were made on a 3D printer using the FDM method. The counter-sample was a ring made of aluminium alloy subjected to anodizing. The research was carried out under a variable loads, in reciprocating motion, under dry friction conditions. After that the tribological characteristics were assessed. The research and analysis of the results confirmed the possibility of using selected plastics in modes of transport.

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Applicability of Interrupted Micro Cutting Process “Tilling” as Surface Texturing

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.749.241 ◽

2017 ◽

Vol 749 ◽

pp. 241-245 ◽

Cited By ~ 3

Author(s):

Hatsuhiko Usami ◽

Toshiki Sato ◽

Yasuyuki Kanda ◽

Satoru Nishio

Keyword(s):

Friction Coefficient ◽

Tribological Properties ◽

Cast Alloy ◽

Effective Means ◽

Frictional Resistance ◽

Cnc Machining ◽

Cutting Process ◽

Textured Surface ◽

Textured Surfaces ◽

Micro Cutting

Tribological properties of textured surfaces fabricated using a discontinuous microcutting process were investigated. Aluminum cast alloy (AC8A) discs were used for the specimens. The texturing process was carried out using a CNC machining center with a cutting edge with a novel geometry. The resulting surface morphology consisted of micro dimples with a diameter of 200-300 μm and a depth of 5-10 μm, with controlled area fractions of 10 and 40% and a top region finished with a milling cut. The tribological properties were evaluated using a ring-on-disc type testing apparatus under lubricated conditions, and showed that the friction coefficient of the textured surfaces was low and stable from the beginning of the experiment. A dependence of the friction coefficient on the area fraction was also found. Further reductions in the friction coefficient were achieved on a textured surface with a polished top region. It can be concluded that the proposed discontinuous micro cutting process is an effective means of fabricating a micro texture for the reduction and stabilization of frictional resistance.

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