scholarly journals Improving the Tribological Properties of Technical Polymers with Metal Sulphide Compounds

Lubricants ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 91
Author(s):  
Andreas Hausberger ◽  
Tanja Stiller ◽  
Clemens Kappl ◽  
Lars Hensgen ◽  
Florian Grün
Keyword(s):  
Wear Rate ◽  
Tribological Properties ◽  
Glass Fibre ◽  
High Performance ◽  
Solid Lubricants ◽  
Solid Lubrication ◽  
Wear Behaviour ◽  
Rate Reduction ◽  
Tribological Behaviour ◽  
Metal Sulphide

Technical thermoplastic materials (e.g., PEEK, PPA and POM) are widely used for tribological applications combined with different filler systems (e.g., glass- or carbon fibres) because of their excellent mechanical properties. The friction and wear behaviour of thermoplastics can be specifically improved by solid lubrication systems such as graphite, PTFE and MoS2. Besides these systems, others such as WoS2 and MnS are becoming scientifically interesting. This work investigates the influence of different solid lubricants—alternative metal sulphides and polymer-based—in combination with different glass fibre contents on the tribological behaviour of unfilled PEEK and glass fibre-filled PPA. For this purpose, compounds were produced and injection-moulded into tribological test specimens that were subsequently tested. It is particularly evident for both matrix materials that the solid lubricant SLS 22 shows a 25% wear rate reduction when compared to MoS2 and, in addition, the proportion of fibre content in PPA shows an additional wear rate reduction by a factor of 10. The friction level could be kept at a similar level compared to the usually utilised solid lubricants. The investigations showed the potential use of metal sulphide filler systems in high-performance thermoplastic with enhanced tribological properties as alternatives to the well-established solid lubricants.

Friction and Wear Behaviors of Solid Lubricants/Polyimide Composites in Liquid Mediums

2010 ◽  
Vol 654-656 ◽  
pp. 2763-2766 ◽  
Author(s):  
Li Wen Mu ◽  
Xin Feng ◽  
Yi Jun Shi ◽  
Huai Yuan Wang ◽  
Xiao Hua Lu
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Alkaline Solution ◽  
Dry Friction ◽  
Friction And Wear ◽  
Solid Lubricants ◽  
Polyimide Composites ◽  
Inorganic Fillers ◽  
Ptfe Composites

The tribological properties of polyimide (PI) composites reinforced with graphite or MoS2 sliding in liquid alkali and water as well as dry friction were investigated using a ring-on-ring tester. The results show that the friction coefficient (μ) and wear rate (W) for both graphite/PI and MoS2/PI composites in different liquid mediums are μdry>μwater >μalkali and Wwater>Wdry >Walkali. Results also indicate that the friction coefficient and wear rate of the PI composites filled with different solid lubricants are μMoS2 >μgraphite and W MoS2 >Wgraphite in different liquid mediums. In addition, the hydrophobic inorganic fillers are fit for the reinforcement of polymer-based composites sliding in liquid mediums. It is also concluded from the authors’ work that the wear rate and friction coefficient of polymer-based (such as PI, PTFE) composites in the alkali lubricated conditions is lowest among all the friction conditions. This may be attributed to the ionic hydration in the alkaline solution.

Mechanical and tribological properties of ice-bonded abrasive polishing tools

2017 ◽  
Vol 233 (1) ◽  
pp. 132-144 ◽  
Author(s):  
S Rambabu ◽  
N Ramesh Babu
Keyword(s):  
Wear Rate ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Melting Rate ◽  
Wear Behaviour ◽  
Mechanical And Tribological Properties ◽  
Different Temperatures ◽  
Long Time ◽  
Polishing Tool ◽  
Hardness Coefficient

This article covers the efforts on characterising ice-bonded abrasive polishing tool in terms of the mechanical and tribological properties such as hardness, coefficient of friction, and wear rate. These studies were attempted on the tools prepared at different temperatures ranging from −10 °C to 0 °C with a view to identify the condition suitable to prepare ice-bonded abrasive polishing tool for effective polishing of Ti–6Al–4V alloy specimen. It also presents the methods adopted to determine various properties of ice-bonded abrasive polishing tool. Hardness was estimated from the measured penetration depth of cone shape indenter into the tool, coefficient of friction was determined from the change in power drawn by the motor rotating the tool mould, and wear behaviour of tool was assessed from the melting rate of the tool determined from the change in height of ice-bonded abrasive polishing tool at different stages of polishing. From the results of this study, it is clear that ice-bonded abrasive polishing tool prepared at −4 °C has possessed sufficient hardness, coefficient of friction, and reasonable wear rate suitable for polishing of Ti–6Al–4V specimens. This article also covers the details of low-temperature coolant supply unit developed to prepare the ice-bonded abrasive polishing tool at any desired temperature between 0 °C and −40 °C and thus to maintain it for a long time. Polishing studies with such ice-bonded abrasive polishing tool showed 72% improvement in finish after 90 min of polishing of Ti–6Al–4V specimen with tool, prepared at −4 °C.

A study on tribological behaviour and analysis of ZnO reinforced AA6061 matrix composites fabricated by stir casting route

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sakthi Sadhasivam RM ◽  
Ramanathan K. ◽  
Bhuvaneswari B.V. ◽  
Raja R.
Keyword(s):  
Wear Rate ◽  
Sliding Wear ◽  
Stir Casting ◽  
Industrial Applications ◽  
Wear Behaviour ◽  
Matrix Composites ◽  
Tribological Behaviour ◽  
Content Type ◽  
Zno Particles ◽  
The Matrix

Purpose The most promising replacements for the industrial applications are particle reinforced metal matrix composites because of their good and combined mechanical properties. Currently, the need of matrix materials for industrial applications is widely satisfied by aluminium alloys. The purpose of this paper is to evaluate the tribological behaviour of the zinc oxide (ZnO) particles reinforced AA6061 composites prepared by stir casting route. Design/methodology/approach In this study, AA6061 aluminium alloy matrix reinforced with varying weight percentages (3%, 4.5% and 6%) of ZnO particles, including monolithic AA6061 alloy samples, is cast by the most economical fabrication method, called stir casting. The prepared sample was subjected to X-ray photoelectron spectroscopy (XPS) analysis, experimental density measurement by Archimedian principle and theoretical density by rule of mixture and hardness test to investigate mechanical property. The dry sliding wear behaviour of the composites was investigated using pin-on-disc tribometer with various applied loads of 15 and 20 N, with constant sliding velocity and distance. The wear rate, coefficient of friction (COF) and worn surfaces of the composite specimens and their effects were also investigated in this work. Findings XPS results confirm the homogeneous distribution of ZnO microparticles in the Al matrix. The Vickers hardness result reveals that higher ZnO reinforced (6%) sample have 34.4% higher values of HV than the monolithic aluminium sample. The sliding wear tests similarly show that increasing the weight percentage of ZnO particles leads to a reduced wear rate and COF of 30.01% and 26.32% lower than unreinforced alloy for 15 N and 36.35% and 25% for 20 N applied load. From the worn surface morphological studies, it was evidently noticed that ZnO particles dispersed throughout the matrix and it had strong bonding between the reinforcement and the matrix, which significantly reduced the plastic deformation of the surfaces. Originality/value The uniqueness of this work is to use the reinforcement of ZnO particles with AA6061 matrix and preparing by stir casting route and to study and analyse the physical, hardness and tribological behaviour of the composite materials.

Sliding wear characteristics of grey cast iron as affected by the type and fraction of solid lubricants in oil

2014 ◽  
Vol 66 (5) ◽  
pp. 569-578
Author(s):  
B.K. Prasad
Keyword(s):  
Cast Iron ◽  
Wear Rate ◽  
Sliding Wear ◽  
Frictional Heating ◽  
Solid Lubricants ◽  
Grey Cast Iron ◽  
Wear Behaviour ◽  
Specific Response ◽  
Content Type ◽  
Grey Cast

Purpose – The purpose of the paper is to assess the influence of the volume fraction solid lubricants like talc lead and graphite in oil separately and in combination towards controlling the sliding wear behaviour of a grey cast iron and understand the factors controlling the response of the material in a given set of experimental conditions. Design/methodology/approach – The composition of the lubricating medium (oil) has been changed by dispersing 5 per cent graphite, talc and lead particles separately and in combination. Sliding wear tests were conducted on grey cast iron samples over a range of applied pressures. Parameters determined were wear rate and frictional heating. The wear behaviour of the samples was further substantiated through the features of wear surfaces, subsurface regions and debris particles. Material removal mechanisms and factors responsible for a specific response of the samples have also been analysed. Findings – The wear rate increased with increasing applied pressure. Addition of graphite and lead to the oil separately or in combination brought about a reduction in the wear rate of the samples; talc and talc + lead produced a reverse trend. Temperature near the specimen surface increased with test duration and applied pressure. The test environment influenced the frictional heating in a manner similar to that of the wear rate. Adhesion and abrasion were observed to be the operating material removal mechanisms. Smearing of the solid lubricating phase and delamination resulting from cracking tendency also controlled the wear response. Research limitations/implications – Oil is a very popular lubricant used in engineering applications involving friction and wear. Solid lubricants are used along with the oil. The nature, characteristics and content of the solid lubricants very much control the performance. Limited information is available pertaining to assessing the influence of the type and fraction of solid lubricants in the oil towards controlling the wear behaviour of cast irons (popularly known tribomaterials). The present study enables to understand the effectiveness of talc, lead and graphite in oil towards governing the wear characteristics of cast iron and analyse wear mechanisms and controlling parameters. Practical implications – Graphite and talc are available in nature in abundance. Graphite is a popularly known solid lubricant, while talc is less explored. Lead is also well-known as a solid lubricant but poses health hazard in practice due to its toxic nature. The present study explores the lubricating capability of talc when mixed with oil separately or in combination with lead and graphite towards controlling the wear response of a grey cast iron. It enables to understand the factors responsible for the specific response of talc. Social implications – Assessment of the lubricating potential of talc as a possible substitute to lead is important in view of the toxic nature of the latter. If successful, the exercise could enable to replace lead with talc. Originality/value – The present manuscript is an original piece of the author's research work.

Thermal effects on mild wear transition in dry sliding of aluminium 7075-short glass fibre composites

2002 ◽  
Vol 216 (12) ◽  
pp. 975-982 ◽  
Author(s):  
S C Sharma ◽  
M Krishna ◽  
P S Vizhian ◽  
A Shashishankar
Keyword(s):  
High Temperature ◽  
Wear Rate ◽  
Glass Fibre ◽  
Operating Temperature ◽  
Wear Behaviour ◽  
Unreinforced Alloy ◽  
Wear Rates ◽  
Short Glass Fibre ◽  
Wear Transition ◽  
Short Glass

The unlubricated sliding high temperature wear behaviour of A17075 alloy composites reinforced with short E-glass fibre was evaluated. A17075-glass composites were prepared by the liquid metallurgical technique with 2, 4 and 6 per cent by weight. A high temperature sliding wear apparatus, with temperature range 30-200°C, was used to evaluate the wear rate. Results indicated that addition of short glass fibre to A17075 alloy not only delays the transition wear (transition between mild and severe wear) but also reduces the wear rate. However, in both unreinforced alloy and reinforced composites, the wear rates increased with increases in the load, operating temperature and sliding speed. Increase in the applied load and operating temperature increased the wear severity by changing the wear mechanism from adhesion wear to debris cracking induced delamination wear. The observations have been explained using scanning electron microscopy, X-ray diffraction and energy-dispersive spectroscopy analysis of the worn surfaces and the debris.

The synergistic effect of SiC/R-GO composite on mechanical and tribological properties of thermosetting polyimide

2021 ◽  
pp. 002199832110492
Author(s):  
Aijiao Li ◽  
Suoxiao Wang ◽  
Zhe Chen ◽  
Hong Liu ◽  
Hongding Wang
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
High Performance ◽  
In Situ Polymerization ◽  
Effective Means ◽  
Compression Modulus ◽  
Nanocomposite Films ◽  
Mechanical And Tribological Properties ◽  
Industry Applications

The effective means to solve material wear is to develop self-lubricating composite materials with excellent tribological, thermal, and mechanical properties. Herein, the composites of reduced graphene oxide (r-GO) nanosheet decorated with Silicon Carbide (SiC) were facilely prepared with employing a silane coupling agent, and the corresponding r-GO/SiC/thermosetting polyimide (r-GO/SiC/TPI) nanocomposite films were obtained by in situ polymerization method. The mechanical, tribological, and thermal properties of these nanocomposite films were investigated. When the content of r-GO/SiC was at 1.0 wt%, the compression strength and compression modulus of the composite increased by 37.7% and 47.3%, respectively, which were much higher than that of TPI composites addition of r-GO or SiC alone. Furthermore, r-GO/SiC/TPI composites also exhibited the lowest wear rate and friction coefficient in these reinforced TPI nanocomposites. When the content of r-GO/SiC was 0.8 wt%, particularly, the friction coefficient and wear rate of r-GO/SiC/TPI decreased by 22.8% and 79.8% compared to pure TPI, respectively. Additionally, trace amount r-GO/SiC hybrids also significantly enhance the thermal stability of TPI matrix. Compared to the polyimide composites reinforced by common nano-scale inorganic fillers, the outstanding mechanical and tribological properties of this r-GO/SiC/PI composites could be attributed to the ball on plane structure of GO/SiC, which lead to crack reflection, strength increment. These r-GO/SiC/TPI composites demonstrate the promising potential to be used as high-performance tribological materials in industry applications.

scholarly journals Extruded and Injection Moulded Virgin PA 6/6 as Abrasion Resistant Material

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
J. Sukumaran ◽  
R. Keresztes ◽  
G. Kalácska ◽  
H. Almaliki ◽  
P. D. Neis ◽  
...  
Keyword(s):  
Wear Rate ◽  
Extrusion Process ◽  
Wear Behaviour ◽  
Protective Agent ◽  
Tribological Behaviour ◽  
Wear Performance ◽  
Wear Response ◽  
Wear Tests ◽  
Proper Balance ◽  
Increasing Load

Polyamide (PA6/6) is often used as a tribological pair in abrasion prevalent applications such as hinges and sliders. PA6/6 is frequently processed by injection moulding and extrusion process. It is known that these processes influence the polymers mechanical behaviour, but their influence on the polymers wear response has not been studied. Hence the present research attempts to study the influence of different manufacturing processes on tribological behaviour for PA6/6. Wear tests were performed on a pin abrading tester (DIN 50322). Abrasion resistance of both extruded and injection moulded PA6/6 were tested at different loads (20 and 35 N). Single-pass (nonoverlapping mode) and multipass testing (overlapping mode) were used to understand the influence of clogging of wear debris. It is evidenced that with increasing load the specific wear rate decreases; moreover, fine abrasives tend to reduce the wear rate. In multipass testing a transfer layer clogged on the counterface that acted as a protective agent and lowers wear rate. Poor mechanical strength of injection moulded polymers is apparently compensated by microstructural response for having a similar wear behaviour between extruded and injection moulded PA 6/6. Hence a proper balance between microstructural and mechanical characteristics is an absolute must in PA 6/6 for better wear performance.

Multi Objective Optimization of Wear Behaviour of In Situ AA8011-ZrB2 Metal Matrix Composites by Using Taguchi-Grey Analysis

2018 ◽  
Vol 928 ◽  
pp. 162-167 ◽  
Author(s):  
B.M. Muthamizh Selvan ◽  
V. Anandakrishnan ◽  
Muthukannan Duraiselvam ◽  
R. Venkatraman ◽  
S. Sathish
Keyword(s):  
Wear Rate ◽  
Microscopic Analysis ◽  
Casting Process ◽  
Stir Casting ◽  
Wear Behaviour ◽  
Dry Sliding Wear ◽  
Homogeneous Distribution ◽  
Tribological Behaviour ◽  
Electron Microscopic

Composite materials with aluminium alloy 8011 matrix and 0, 4 and 8 weight percentages of ZrB2reinforcements were synthesized by in-situ stir casting process. The presence and homogeneous distribution of the reinforcements were examined with X-ray diffraction analysis and scanning electron microscopic analysis. To investigate the effect of dry sliding wear parameters such as sliding distance, percentage reinforcement, load, sliding velocity and temperature on wear rate and co-efficient of friction, experiments were conducted using a pin on disc wear tester as per Taguchi’s orthogonal array design and the tribological behaviour of synthesized composites was investigated by statistical techniques. Significance and the influence of the parameters over the response were determined by analysis of variances and grey relational analysis was used to find the optimal combination of parameters to obtain minimum wear rate and co-efficient of friction.

scholarly journals Micro/Nanostructure and Tribological Characteristics of Pressureless Sintered Carbon Nanotubes Reinforced Aluminium Matrix Composites

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
P. Manikandan ◽  
R. Sieh ◽  
A. Elayaperumal ◽  
H. R. Le ◽  
S. Basu
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
High Energy ◽  
Wear Behaviour ◽  
Powder Metallurgy Method ◽  
Pure Aluminium ◽  
Matrix Composites ◽  
Reinforced Composites ◽  
Tribological Behaviour ◽  
Mechanically Alloyed

This study reports the manufacture, microstructure, and tribological behaviour of carbon nanotube reinforced aluminium composites against pure aluminium. The specimens were fabricated using powder metallurgy method. The nanotubes in weight percentages of 0.5, 1.0, 1.5, and 2.0 were homogeneously dispersed and mechanically alloyed using a high energy ball milling. The milled powders were cold compacted and then isothermally sintered in air. The density of all samples was measured using Archimedes method and all had a relative density between 92.22% and 97.74%. Vickers hardness increased with increasing CNT fraction up to 1.5 wt% and then reduced. The microstructures and surfaces were investigated using high resolution scanning electron microscope (SEM). The tribological tests showed that the CNT reinforced composites displayed lower wear rate and friction coefficient compared to the pure aluminium under mild wear conditions. However, for severe wear conditions, the CNT reinforced composites exhibited higher friction coefficient and wear rate compared to the pure aluminium. It was also found that the friction and wear behaviour of CNT reinforced composites is significantly dependent on the applied load and there is a critical load beyond which CNTs could have adverse impact on the wear resistance of aluminium.

scholarly journals Effect of Addition of Graphite on Tribological Behaviour of Sic and Fly Ash Reinforced Copper Based Self-Lubricating Composites

2019 ◽  
Vol 8 (4S2) ◽  
pp. 976-978
Keyword(s):  
Fly Ash ◽  
Powder Metallurgy ◽  
Tribological Properties ◽  
Wear Behaviour ◽  
Loading Conditions ◽  
Tribological Behaviour ◽  
Graphite Content ◽  
Powder Metallurgy Process ◽  
Metallurgy Process ◽  
Self Lubricating Composites

In the present study 4 different combinations of composites are prepared with varying proportions of graphite content by keeping the same proportion of copper, SiC and Fly ash through powder metallurgy process. hardness, Microstructure and tribological properties are studied with varying sliding velocities(1, 2 & 3m/s) and loading conditions (10, 30 and 50N). The addition of graphite reduces the hardness, but the wear behaviour is enhanced with its addition.

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