scholarly journals A Novel Reciprocating Tribometer for Friction and Wear Measurements with High Contact Pressure and Large Area Contact Configurations

Lubricants ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 123
Author(s):  
Kim Berglund ◽  
Maria Rodiouchkina ◽  
Jens Hardell ◽  
Kalle Kalliorinne ◽  
Jens Johansson
Keyword(s):  
Contact Pressure ◽  
Friction And Wear ◽  
Guide Vane ◽  
Operating Conditions ◽  
Test Method ◽  
Large Area ◽  
Contact Pressures ◽  
High Contact Pressure ◽  
Wear Tests ◽  
Friction And Wear Tests

There are many moving machine assemblies with conformal tribological contacts at very high contact pressures, e.g., sliding bearings, propeller shaft bearings and machine guideways. Furthermore, applications such as trunnion and guide vane bearing in Kaplan turbines have very low sliding speeds and oscillatory types of motion. Although there is a vast selection of tribology test rigs available, there is still a lack of test equipment to perform friction and wear tests under high contact pressure, reciprocatory sliding and large area contact. The aim of this work is thus to develop a novel reciprocating tribometer and test method that enables friction and wear tests under low-speed reciprocatory sliding with contact pressures up to 90 MPa in a flat-on-flat contact configuration. First, a thorough description of the test rig design is given. Secondly, the influence of contact pressure and stroke length on the tribological properties of a stainless steel and polymer composite material combination is studied. The significance of considering creep, friction during the stroke and contact temperature is specifically highlighted. The novel tribometer can be used to screen different bearing and shaft material combinations and to evaluate the friction and wear performance of self-lubricating bearings for the specific operating conditions found in Kaplan turbines.

scholarly journals A New Compression-Torsion-Tribometer with Scalable Contact Pressure for Characterization of Tool Wear during Plastic Deformation

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Marco Teller ◽  
Simon Seuren ◽  
Markus Bambach ◽  
Gerhard Hirt
Keyword(s):  
Yield Stress ◽  
Contact Pressure ◽  
Friction And Wear ◽  
Wear Behaviour ◽  
Cold Extrusion ◽  
Workpiece Material ◽  
Contact Pressures ◽  
High Contact Pressure ◽  
Multiple Load

A contact pressure which reaches up to ten times the yield stress of the workpiece material is characteristic for cold extrusion processes. Common tests for friction and wear are limited to rather low contact pressures. Thus, the aim of this paper is to present a new compression-torsion-tribometer which is able to scale the contact pressure to a multiple of the yield stress of the workpiece. In order to enable a contact pressure that greatly exceeds the yield stress of the workpiece material, the workpiece specimen is encapsulated laterally. As main parameters, contact pressure, glide length, and relative velocity can be adjusted independently, thus allowing for multiple load cycles. The resulting torque is measured continuously as an indicator for wear. Afterwards wear can be also quantified by examination of surfaces. Hence, the developed setup enables a comparison of tool surfaces and coatings and a characterization of wear behaviour under high contact pressure.

Tribological behavior of UHMWPE in water lubrication: the effect of molding temperature

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xincong Zhou ◽  
Chaozhen Yang ◽  
Jian Huang ◽  
Xueshen Liu ◽  
Da Zhong ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Friction Coefficient ◽  
Friction And Wear ◽  
Wear Loss ◽  
Content Type ◽  
Molding Temperature ◽  
Melting Temperatures ◽  
Ultra High Molecular Weight ◽  
Wear Tests ◽  
Friction And Wear Tests

Purpose Ultra-high molecular weight polyethylene (UHMWPE) is adopted in water-lubricated bearings for its excellent performance. This paper aims to investigate the tribological properties of UHMWPE with a molecular weight of 10.2 million (g mol‐1) under different molding temperatures. Design/methodology/approach The UHMWPE samples were prepared by mold pressing under constant pressure and different molding temperatures (140°C, 160°C, 180°C, 200°C, 220°C). The friction and wear tests in water were conducted at the RTEC tribo-tester. Findings The friction coefficient and wear loss decreased first and rose later with the increasing molding temperature. The minimums of the friction coefficient and wear loss were found at the molding temperatures of 200°C. At low melting temperatures, the UHMWPE molecular chains could not unwrap thoroughly, leading to greater abrasive wear. On the other hand, high melting temperatures will cause the UHMWPE molecular chains to break up and decompose. The optimal molding temperatures for UHMWPE were found to be 200°C. Originality/value Findings are of great significance for the design of water-lubricated UHMWPE bearings.

Hydrogen-Induced Wear of Ti–6Al–4V Alloy

2012 ◽  
Vol 476-478 ◽  
pp. 566-569
Author(s):  
Bao Guo Yuan ◽  
Hai Ping Yu ◽  
Ping Li ◽  
Gui Hua Xu ◽  
Chun Feng Li ◽  
...  
Keyword(s):  
Wear Mechanism ◽  
Chemical Element ◽  
Friction And Wear ◽  
Room Temperature ◽  
Sliding Friction ◽  
Wear Properties ◽  
Friction And Wear Properties ◽  
Worn Surface ◽  
Wear Tests ◽  
Friction And Wear Tests

The effects of hydrogen on friction and wear properties of Ti–6Al–4V alloy sliding against GCr15 steel were investigated through dry sliding friction and wear tests in atmosphere at room temperature. Wear mechanism was determined by studying the morphology and chemical element of worn surface using SEM and EDS. Results show that friction coefficient decreases slightly and wear rate increases after hydrogenation. Wear mechanism is discussed.

The tribological performance of engineered micro-surface topography by picosecond laser on PEEK

2019 ◽  
Vol 72 (1) ◽  
pp. 172-179 ◽  
Author(s):  
Meiling Wang
Keyword(s):  
Tribological Properties ◽  
Design Methodology ◽  
Friction And Wear ◽  
Picosecond Laser ◽  
Wear Property ◽  
Content Type ◽  
Friction Curve ◽  
Micro Structures ◽  
Wear Tests ◽  
Friction And Wear Tests

Purpose The purpose of this study is to investigate the effect of engineered micro-structures on the tribological properties of metal-polyetheretherketone (PEEK) surface. Design/methodology/approach Circular dimples with diameters of 25 and 50 µm were designed and manufactured on PEEK plate specimens using picosecond laser. Reciprocating friction and wear tests on a ball-on-flat configuration were performed to evaluate the tribological properties of the designed micro-structures in dry contacts. The loading forces of 0.9 and 3 N were applied. Findings As a result, obvious fluctuations of coefficient of friction curve were observed in tribosystems consisting of non-textured and textured PEEK with circular dimples of 25 µm in diameter. GCr15 ball/textured PEEK plate specimens with circular dimples of 50 µm in diameter revealed a superior friction and wear property. Originality/value Different to the existing studies in which the tribopairs consist of hard bearing couples, this study investigated the tribological properties of the engineered micro-structures on the hard-on-soft bearing couples.

Friction and Wear Reduction of 440C Stainless Steel by Ion Implantation

1983 ◽  
Vol 27 ◽  
Author(s):  
L. E. Pope ◽  
F. G. Yost ◽  
D. M. Follstaedt ◽  
S.T. Picraux ◽  
J. A. Knapp
Keyword(s):  
Stainless Steel ◽  
Surface Layer ◽  
Yield Strength ◽  
Ion Implantation ◽  
Friction And Wear ◽  
No Reduction ◽  
Wear Reduction ◽  
Amorphous Surface ◽  
Wear Tests ◽  
Friction And Wear Tests

ABSTRACTFriction and wear tests on ion-implanted 440C stainless steel discs have been extended to high Hertzian stresses (≤ 3150 MPa). Implantation of 2 × 1015 Ti/mm2 (180–90 keV) and 2 × 1015 C/mm2 (30 keV) into 440C reduces friction (∼40%) and wear (> 80%) for Hertzian stresses as large as 2900 MPa, stresses which significantly exceed the yield strength of 440C (∼1840 MPa). Implantation of 4 × 1015 N/mm2 (50 keV) into 440C reduces friction slightly (∼25%) for Hertzian stresses > 1840 MPa but provides little or no reduction in wear. The amount of Ti remaining in the wear tracks correlates with the reductions in friction and wear. The implantation of Ti and C produces an amorphous surface layer which is believed to reduce friction and wear, whereas N implantation is expected to produce hard nitride particles which probably do not modify the hardness of 440C (KHN = 789) significantly.

Wear Mechanism and Self Lubrication of Engineering Ceramics at Elevated Temperatures

2008 ◽  
Vol 368-372 ◽  
pp. 1092-1095 ◽  
Author(s):  
Han Ning Xiao ◽  
Ji Xiang Yin ◽  
Tetsuya Senda
Keyword(s):  
Wear Rate ◽  
Wear Mechanism ◽  
Friction And Wear ◽  
Elevated Temperatures ◽  
Testing Temperature ◽  
Nano Particles ◽  
Wear Loss ◽  
Pressure Oxidation ◽  
Wear Tests ◽  
Friction And Wear Tests

Friction and wear tests of Al2O3 and SiC were conducted from room temperature to 1200°C both in air and in vacuum. Results show that the wear mechanism of Al2O3 is dominated by micro fracture, debris abrasive and delamination at temperatures below 600 °C, while is controlled by plastic deformation and recrystallization among 600~1200 °C, resulting in an obvious decrease of wear loss. The wear rate and surface microstructure of SiC are closely depending on the testing temperature, atmosphere and contact pressure. Oxidation of SiC at elevated temperatures plays important role on the wear rate. Self lubrication of both Al2O3 and SiC at high temperatures was observed, which is mainly depending on the formation of a specific surface layer composed of nano-particles or very thin glassy film.

Friction and wear tests of polymers

Wear ◽  
1987 ◽  
Vol 115 (1-2) ◽  
pp. 95-105 ◽  
Author(s):  
Kenneth Holmberg ◽  
Göran Wickström
Keyword(s):  
Friction And Wear ◽  
Wear Tests ◽  
Friction And Wear Tests

Frictional Layer and Its Antifriction Effect in High-Purity Ti3SiC2 and TiC-Contained Ti3SiC2

2007 ◽  
Vol 280-283 ◽  
pp. 1347-1352 ◽  
Author(s):  
Hong Xiang Zhai ◽  
Zhen Ying Huang ◽  
Yang Zhou ◽  
Zhi Li Zhang ◽  
Yi Fan Wang
Keyword(s):  
Friction Coefficient ◽  
High Purity ◽  
Friction And Wear ◽  
Low Carbon Steel ◽  
Normal Pressure ◽  
Layer By Layer ◽  
Low Carbon ◽  
Friction Surfaces ◽  
Wear Tests ◽  
Friction And Wear Tests

Characteristics of the frictional layer in high-purity Ti3SiC2 and TiC-contained Ti3SiC2, sliding against low carbon steel, were investigated. The friction and wear tests were made using a block-on-disk type friction tester with sliding speed of 20 m/s and several normal pressures from 0.1 MPa to 0.8 MPa. It was found that all friction surfaces, whether high-purity Ti3SiC2 or TiC-contained Ti3SiC2, were covered by a layer consisting of the oxides of Ti, Si and Fe. The layer was sticky, superimposed layer-by-layer, and the compact was increased with the normal pressure increasing. Because its antifriction effect, the friction coefficient decreases from the maximum 0.35 to 0.27 with increase in the normal pressure from 0.2 MPa to 0.8 MPa for the high-purity Ti3SiC2, and decreases from the maximum 0.55 to 0.37 for the same change of the normal pressure for the TiC-contained Ti3SiC2. The contained TiC grains had effects on the stickiness, liquidness, as well as the morphology of the layer, and induced the friction coefficient to increase in the entire level.

Central and Minimum Elastohydrodynamic Film Thickness at High Contact Pressure

1997 ◽  
Vol 119 (2) ◽  
pp. 291-296 ◽  
Author(s):  
M. Smeeth ◽  
H. A. Spikes
Keyword(s):  
High Pressure ◽  
Film Thickness ◽  
Contact Pressure ◽  
Applied Load ◽  
Optical Technique ◽  
Test Rig ◽  
Minimum Film Thickness ◽  
Elastohydrodynamic Film Thickness ◽  
Contact Pressures ◽  
High Contact Pressure

A new optical technique has been developed which is able to obtain accurate film thickness profiles across elastohydrodynamic (EHD) contacts. This has been used in conjunction with a high pressure EHD test rig to obtain both central and minimum EHD film thicknesses at high contact pressures up to 3.5 GPa. The results have been compared with the classical film thickness equations of Hamrock and Dowson and also with recent high pressure computations due to Venner. It is found that minimum film thickness falls more rapidly with applied load at high than at low contact pressures, with a film thickness/load exponent of −0.3. This confirms the findings of recent high pressure computational EHD modeling.

Sign in / Sign up

Export Citation Format

Share Document