Tribological behaviour of recursive friction stir processed AA7075

2020 ◽  
Vol 72 (7) ◽  
pp. 887-894 ◽  
Author(s):  
Girish G. ◽  
Anandakrishnan V.
Keyword(s):  
Peer Review ◽  
Tribological Properties ◽  
Testing Machine ◽  
Traverse Speed ◽  
Wear Testing ◽  
Tribological Behaviour ◽  
Content Type ◽  
Friction Stir ◽  
Pin On Disc ◽  
7075 Alloy

Purpose This study aims to investigate and present the tribological behaviour of recursively friction stir processed 7075 aluminium alloy. Design/methodology/approach In this work, aluminium 7075 alloy is friction stir processed recursively by varying the tool rotational speed, traverse speed and the number of passes. Wear pins for testing were extracted from the processed zone and the surfaces were prepared. Wear tests were conducted as per the standard on a pin-on-disc wear testing machine at constant testing conditions and the corresponding tribological properties were analysed. The worn surface and the debris were analysed using a field-emission scanning electron microscope with energy dispersive spectroscopy analysis and elemental mapping to identify the mode of wear mechanism. Findings The experimental results indicate that the specimen fabricated at 1,150 rpm of tool rotation speed and 60 mm/min of traverse speed with 4 passes had the highest wear resistance and the minimum friction coefficient. Originality/value This paper details the effect of recursive friction stir processing on the surface of AA 7075 to improve the tribological properties. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2020-0070/

Tribological properties of MoS2 powder-lubricated interface

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Cong Liu ◽  
Yanguo Yin ◽  
Baohong Tong ◽  
Guotao Zhang
Keyword(s):  
Peer Review ◽  
Tribological Properties ◽  
Testing Machine ◽  
Point Contact ◽  
Contact Friction ◽  
Content Type ◽  
Friction Noise ◽  
Sliding Interface ◽  
Lubrication Performance ◽  
Powder Lubrication

Purpose This study aims to investigate the effect of MoS2 powder on tribological properties of sliding interfaces. Design/methodology/approach Loose MoS2 powder was introduced in the gap of point-contact friction pairs, and sliding friction test was conducted using a testing machine. Friction noise, wear mark appearance, microstructure and wear debris were characterized with a noise tester, white-light interferometer, scanning electron microscope and ferrograph, respectively. Numerical simulation was also performed to analyze the influence of MoS2 powder on tribological properties of the sliding interface. Findings MoS2 powder remarkably improved the lubrication performance of the sliding interface, whose friction coefficient and wear rate were reduced by one-fifth of the interface values without powder. The addition of MoS2 powder also reduced stress, plastic deformation and friction temperature in the wear mark. The sliding interface with MoS2 powder demonstrated lower friction noise and roughness compared with the interface without powder lubrication. The adherence of MoS2 powder onto the friction interface formed a friction film, which induced the wear mechanism of the sliding interface to change from serious cutting and adhesive wear to delamination and slight cutting wear under the action of normal and shear forces. Originality/value Tribological characteristics of the interface with MoS2 powder lubrication were clarified. This work provides a theoretical basis for solid-powder lubrication and reference for its application in engineering. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-04-2020-0150/

Study on friction characteristics of sliding interface of feed system

2020 ◽  
Vol 72 (7) ◽  
pp. 865-871
Author(s):  
Pan-Pan Li ◽  
Feng Gao ◽  
Yan Li ◽  
Bo Yang
Keyword(s):  
Friction Coefficient ◽  
Peer Review ◽  
Working Conditions ◽  
Contact Surface ◽  
Testing Machine ◽  
Mixed Lubrication ◽  
Wear Testing ◽  
Feed System ◽  
Content Type ◽  
Start Up

Purpose The serious friction caused by the fluctuation of friction occurs when start-up and will reduce the positioning accuracy of the servo axes of high precision machine tools, the purpose of this paper is to study the friction fluctuation characteristics of friction coefficients between interfaces under different working conditions. Design/methodology/approach HT200 and 45# materials were experimentally studied by friction and wear testing machine UMT-3, the variation of friction coefficient under different working conditions (different start-up conditions, the variation of lubrication state area and different roughness) were measured. Findings The results show that the larger start-up acceleration shortens the pre-sliding time of the interface friction, makes the friction coefficient decrease faster, reduces the mixed lubrication area of the contact surface and makes the contact surface reach the stable lubrication state quickly. It can be concluded that the larger roughness surface will lead to the larger mixed lubrication area, the larger static friction coefficient and the larger drop between static and dynamic friction coefficient and easy to cause friction vibration. Originality/value The results reveal the friction fluctuation rule of the metal interface during the different start-up process, which is of guiding significance to reveal the lubrication principle and mechanism of the mechanical interface. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2019-0482/

Study of the microstructure, hardness and tribological behavior of hypoeutectic Al-7Si hybrid composites

2016 ◽  
Vol 68 (2) ◽  
pp. 233-241 ◽  
Author(s):  
BM Viswanatha ◽  
M Prasanna Kumar ◽  
S Basavarajappa ◽  
TS Kiran
Keyword(s):  
Design Methodology ◽  
Tribological Behavior ◽  
Hybrid Composites ◽  
Base Alloy ◽  
Testing Machine ◽  
Wear Testing ◽  
Content Type ◽  
Pin On Disc ◽  
Reinforcement Distribution ◽  
Cast Technique

Purpose – This paper aims to investigate the microstructure, hardness and tribological properties of hypoeutectic (Al-7Si) matrix reinforced with fixed quantities of 3 Wt.% graphite (Gr) and x Wt.% SiCp (x = 3, 6 and 9) hybrid composites. Design/methodology/approach – The composites were fabricated by stir cast technique. The microstructure, hardness and tribological measurements were carried out on the base alloy and composites. The tribological investigation was carried out on pin-on-disc wear testing machine under dry sliding condition. Findings – The wear rate decreases with the increase of SiCp into A356-3Gr composites. The composite containing A356-9SiCp-3Gr had better hardness and good wear resistance compared to the base alloy. Scanning electron microscope (SEM) and electro dispersive spectrometry (EDS) images were used to study the reinforcement distribution and worn-out surface of the specimens. Originality/value – The present paper brings out a clear picture of the various events that take place under the worn-out surfaces leading to the generation of mechanical mixed layer.

The friction and wear behaviors of polyimide bearing retainer under point-contact condition

2020 ◽  
Vol 72 (7) ◽  
pp. 931-936
Author(s):  
Yafeng Zhang ◽  
Shaohua Zhang ◽  
Gang Zhou ◽  
Jiang Zhang ◽  
Tao Qing ◽  
...  
Keyword(s):  
Peer Review ◽  
Wear Debris ◽  
Friction And Wear ◽  
Testing Machine ◽  
Point Contact ◽  
Contact Condition ◽  
Wear Testing ◽  
Sliding Velocity ◽  
Content Type ◽  
Polyimide Composites

Purpose Random point-contact between the space bearing retainer and the rolling elements may cause wear of the space bearing retainer. The paper aims to clarify the friction and wear behaviors of polyimide bearing retainer under point-contact condition. Design/methodology/approach Space bearing retainers were cut into flat specimens and the tribological behaviors of the specimens were studied under point-contact condition using a friction and wear testing machine. Different sliding velocities and normal loads were used to simulate the running state of space bearing retainer. The wear behaviors of the space bearing retainer were analyzed by SEM and white light interferometer. Findings The friction coefficient of the polyimide composites decreased with increase in sliding velocity from 1  to 5 mm/s. Moreover, with increase in sliding velocity and normal load, the wear rate of the polyimide composites decreased and increased, respectively. Moreover, the wear behaviors of the polyimide composites were mainly determined by the combined actions of ploughing friction and adhesive friction. The lubricating properties of transfer film and wear debris were limited under point-contact condition. Practical implications The paper includes implications for the understanding of the wear mechanism of the polyimide composites space bearing retainer under point-contact condition and then to optimize space bearing retainer materials further. Originality/value Under point-contact condition, wear debris can hardly participate in the friction process because of limited contact area. Consequently, the wear debris has limited impact on the wear process to decrease the friction and wear. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2020-0017/

Study on the friction characteristics of 304 steel with composite surface modification

2017 ◽  
Vol 69 (2) ◽  
pp. 248-258 ◽  
Author(s):  
Wengang Chen ◽  
Xueyuan Liu ◽  
Lili Zheng
Keyword(s):  
Surface Modification ◽  
Friction And Wear ◽  
Steel Surface ◽  
Testing Machine ◽  
Wear Testing ◽  
Tribological Characteristics ◽  
Textured Surface ◽  
Content Type ◽  
Good Basis ◽  
Modified Surface

Purpose This paper aims to clarify the friction properties of 304 steel surface modification. The surface modification includes laser texturing processing and nitriding treatment on 304 steel surface, and then the friction properties’ test was conducted on different friction directions and different upper test samples by using microfriction and wear testing machine. Design/methodology/approach The diameter and spacing of 100-, 150-, 200-, 300-μm pit array on the surface of 304 steel were calculated using a M-DPSS-50 semiconductor laser device. Then, the textured surface was nitriding-treated using a nitriding salt bath device. The chemical composition, surface morphology and surface microhardness of the composite-modified surface were measured by X-ray diffraction and by using an optical microscope and a microhardness tester. The tribological characteristics of the composite-modified surface were tested by MRTR microcomputer-controlled multifunctional friction and wear testing machine. Findings The result showed that a rule pit texture surface was obtained by the texture processing. The microhardness of nitriding treatment surface reached 574.27HV0.1, which significantly higher than 222.58HV0.1 of 304 steel. The composite-modified surface has excellent anti-friction and wear resistance properties when the upper specimen was GCr15 steel and ZrO2, respectively. The composite-modified surface has excellent anti-friction and anti-wear properties after long time friction under different angles. However, the friction coefficient and wear morphology of the friction pairs are not affected by the friction angle. Research limitations/implications Because of the chosen research approach, the research results may lack generalizability. Therefore, researchers are encouraged to test the proposed propositions further. Practical implications The paper conducted a systematic study of the tribological characteristics of 304 steel composite modification surface and provided a good basis for the extensive application of 304 steel. Social implications The study provides a good basis for the extensive application of 304 steel. Originality/value This paper fulfils an identified need to study the extensive application of 304 steel.

Effect of Tool Pin Profile on the Microstructure and Tribological Properties of Friction Stir Processed Al-20 wt% Mg2Si Composite

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
A. Moharrami ◽  
A. Razaghian ◽  
M. Emamy ◽  
R. Taghiabadi
Keyword(s):  
Tribological Properties ◽  
Composite Surface ◽  
Cast Composite ◽  
Friction Stir ◽  
Pin On Disc ◽  
Processed Sample ◽  
Tool Pin ◽  
Sliding Distance ◽  
Primary Crystals

Abstract This study was undertaken with the aim of modifying the microstructure and improving the tribological properties of in situ Al-20Mg2Si composite. For this purpose, friction stir processing (FSP) was applied on the composite at constant travel and rotation speeds of 110 mm/min and 1500 rpm, respectively, using three different tool pin profiles: threaded tapered cylindrical, triangular tapered, and triangular threaded tapered. The sliding wear tests were conducted using a pin-on-disc apparatus under the applied load of 30 N and sliding distance of 1000 m at room temperature. The results showed that FSP substantially improved tribological properties of the as-cast composite. The best result was observed in the sample processed by the threaded triangular tapered tool, where compared with the as-cast composite, its wear rate and average friction coefficient decreased by almost 40% and 18%, respectively. This improvement can be attributed to the significant refinement and uniform redistribution of Mg2Si intermetallics, especially the coarse irregular-shaped primary crystals, the formation of ultrafine grains, and elimination of casting defects from the substrate microstructure of the processed sample, which improves its hardness and increased its potential in supporting the oxide tribolayer on the composite surface.

Tribological and physical properties of PTFE-NBR self-lubricating composites under water lubrication

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wei Feng ◽  
Lei Yin ◽  
Yanfeng Han ◽  
Jiaxu Wang ◽  
Ke Xiao ◽  
...  
Keyword(s):  
Physical Properties ◽  
Peer Review ◽  
Tribological Properties ◽  
Water Lubrication ◽  
Butadiene Rubber ◽  
Friction Test ◽  
Bearing Material ◽  
Content Type ◽  
Lubricating Film ◽  
Self Lubricating Composites

Purpose This paper aims to explore the possibility of converting the nitrile butadiene rubber (NBR) water-lubricated bearing material into a self-lubricating bearing material by the action of polytetrafluoroethylene (PTFE) particles and water lubrication. Design/methodology/approach A group of experimental studies was carried out on a ring-on-block friction test. The physical properties, tribological properties and interface structure of PTFE-NBR self-lubricating composites filled with different percentages of PTFE particles were investigated. Findings The experimental results indicated that the reduction in friction and wear is a result of the formation of the lubricating film on the surface of the composites. The lubricating film was formed of a large amount of PTFE particles continuously supplied under water lubrication conditions and the PTFE particles here can greatly enhance the load capacity and lubrication performance. Originality/value In this study, the tribological properties of PTFE particles added to the NBR water-lubricated bearing materials under water lubrication were investigated experimentally, and the research was carried out by a ring-on-block friction test. It is believed that this study can provide some guidance for the application of PTFE-NBR self-lubricating. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2020-0187/

Optimization of friction stir welding process parameters for AA6063-ETP copper using central composite design

2020 ◽  
Vol 17 (4) ◽  
pp. 491-507 ◽  
Author(s):  
Nitin Panaskar ◽  
Ravi Prakash Terkar
Keyword(s):  
Experimental Data ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Rotational Speed ◽  
Traverse Speed ◽  
Tool Rotational Speed ◽  
Content Type ◽  
Friction Stir ◽  
Central Composite

Purpose Recently, several studies have been performed on lap welding of aluminum and copper using friction stir welding (FSW). The formation of intermetallic compounds at the weld interface hampers the weld quality. The use of an intermediate layer of a compatible material during welding reduces the formation of intermetallic compounds. The purpose of this paper is to optimize the FSW process parameters for AA6063-ETP copper weld, using a compatible zinc intermediate filler metal. Design/methodology/approach In the present study, a three-level, three-factor central composite design (CCD) has been used to determine the effect of various process parameters, namely, tool rotational speed, tool traverse speed and thickness of inter-filler zinc foil on ultimate tensile strength of the weld. A total of 60 experimental data were fitted in the CCD. The experiments were performed with tool rotational speeds of 1,000, 1,200 and 1,400 rpm each of them with tool traverse speeds of 5, 10 and 15 mm/min. A zinc inter-filler foil of 0.2 and 0.4 mm was also used. The macrograph of the weld surface under different process parameters and the tensile strength of the weld have been investigated. Findings The feasibility of joining 3 mm thick AA6063-ETP copper using zinc inter-filler is established. The regression analysis showed a good fit of the experimental data to the second-order polynomial model with a coefficient of determination (R2) value of 0.9759 and model F-value of 240.33. A good agreement between the prediction model and experimental findings validates the reliability of the developed model. The tool rotational speed, tool traverse speed and thickness of inter-filler zinc foil significantly affected the tensile strength of the weld. The optimal conditions found for the weld were, rotational speed of 1,212.83 rpm and traverse speed of 9.63 mm/min and zinc foil thickness is 0.157 mm; by using optimized values, ultimate tensile strength of 122.87 MPa was achieved, from the desirability function. Originality/value Aluminium and copper sheets could be joined feasibly using a zinc inter-filler. The maximum tensile strength of joints formed by inter-filler (122.87 MPa) was significantly better as compared to those without using inter-filler (83.78 MPa). The optimum process parameters to achieve maximum tensile strength were found by CCD.

THE INFLUENCE OF THE ADDITION OF GRAPHITE ON THE TRIBOLOGICAL PROPERTIES OF POLYLACTIC (PLA) APPLIED IN 3D PRINTING TECHNOLOGY

Tribologia ◽  
2018 ◽  
Vol 277 (1) ◽  
pp. 89-93 ◽  
Author(s):  
Wojciech PAWLAK ◽  
Wojciech WIELEBA ◽  
Janusz KLUCZYŃSKI ◽  
Lucjan ŚNIEŻEK
Keyword(s):  
3D Printing ◽  
Tribological Properties ◽  
Testing Machine ◽  
Linear Wear ◽  
Optimal Composition ◽  
Fused Filament Fabrication ◽  
Pin On Disc ◽  
The Coefficient Of Friction ◽  
Steel Disc ◽  
Preliminary Research

The article presents the results of studies on the influence of the addition of graphite to a PLA filament on linear wear and the coefficient of friction. A cylinder of 8 millimetre diameter manufactured in Fused Filament Fabrication process, popularly called 3D printing was used as a specimen. Studies were conducted on pin-on-disc testing machine, in which the cylinders mentioned above were paired with a steel disc – the counter-specimen. Specimens used in research were enriched by 5%, 10%, 20%, and 30% of graphite in comparison to the base filament – Natural PLA, which were not enriched with any additions that could improve its tribological properties. The experiment was conducted as a preliminary research. The gained results create a basis to select the optimal composition of additions to the PLA to create a filament with better tribological properties.

scholarly journals Dry Sliding Wear Of Intra-Layer Curaua/Basalt Polyester Composites under Varying PV Conditions

2019 ◽  
Vol 9 (2S2) ◽  
pp. 331-333
Keyword(s):  
Sliding Wear ◽  
Hybrid Composites ◽  
Testing Machine ◽  
Wear Testing ◽  
Dry Sliding Wear ◽  
Wear Properties ◽  
Hybrid Fibers ◽  
Weight Percentage ◽  
Pin On Disc ◽  
Pin On Disk

An investigational analysis was conducted to study the effect of basalt/curaua hybrid composite focusing on wear properties. The hybrid composites are fabricated by resin transfer molding and the tests are conducted by pin on disk as per ASTM G99. Basalt/Curaua relative fiber weight percentage as 0/100,40/60, 60/40, 100/0 are fabricated and analyzed for abrasion wear resistance. Specimens are tested for the load of 50N at 1 m/s using Pin on Disc wear testing machine by varying abrading distance. Worn out surfaces of the abraded composites are studied by using scanning electron microscopy (SEM) and Fourier- transform infrared spectroscopy (FTIR). Roughness of the worn and pure surfaces is also accounted to measure significance of hybridization on tribological properties of the hybrid composites. Result shows that coefficient of friction is increasing in higher the curaua fiber in hybrid composites. Morphology evident the wear mechanism and internal compatibility of hybrid fibers.

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