scholarly journals Tribology of Polymer Blends PBT + PTFE

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 997
Author(s):  
Constantin Georgescu ◽  
Lorena Deleanu ◽  
Larisa Chiper Titire ◽  
Alina Cantaragiu Ceoromila
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Polymer Blends ◽  
Tribological Characteristics ◽  
Linear Wear ◽  
Processing Temperature ◽  
Polybutylene Terephthalate ◽  
Neat Polymer ◽  
Linear Wear Rate ◽  
Uniform Dispersion

This paper presents results on tribological characteristics for polymer blends made of polybutylene terephthalate (PBT) and polytetrafluoroethylene (PTFE). This blend is relatively new in research as PBT has restricted processability because of its processing temperature near the degradation one. Tests were done block-on-ring tribotester, in dry regime, the variables being the PTFE concentration (0%, 5%, 10% and 15% wt) and the sliding regime parameters (load: 1, 2.5 and 5 N, the sliding speed: 0.25, 0.5 and 0.75 m/s, and the sliding distance: 2500, 5000 and 7500 m). Results are encouraging as PBT as neat polymer has very good tribological characteristics in terms of friction coefficient and wear rate. SEM investigation reveals a quite uniform dispersion of PTFE drops in the PBT matrix. Either considered a composite or a blend, the mixture PBT + 15% PTFE exhibits a very good tribological behavior, the resulting material gathering both stable and low friction coefficient and a linear wear rate lower than each component when tested under the same conditions.

scholarly journals Tribology of Polymer Blends PBT + PTFE

2021 ◽  
Author(s):  
Constantin Georgescu ◽  
Lorena Deleanu ◽  
Larisa Chiper (Titire) ◽  
Alina Cantaragiu Ceoromila
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Polymer Blends ◽  
Tribological Characteristics ◽  
Processing Temperature ◽  
Polybutylene Terephthalate ◽  
Neat Polymer ◽  
Uniform Dispersion ◽  
Sliding Distance ◽  
Sem Investigation

This paper presents results on tribological characteristics for polymer blends made of polybutylene terephthalate (PBT) and polytetrafluoroethylene (PTFE). This blend is relatively new in research as PBT has restricted processability because of its processing temperature near the degradation one. Tests were done block-on-ring tribotester, in dry regime, the variables being the PTFE concentration (0%, 5%, 10% and 15%wt) and the sliding regime parameters (load: 1 N, 2.5 N and 5 N, the sliding speed: 0.25 m/s, 0.5 m/s and 0.75 m/s, and the sliding distance: 2500 m, 5000 m and 7500 m). Results are encouraging as PBT as neat polymer has very good tribological characteristics in terms of friction coefficient and wear rate. SEM investigation reveals a quite uniform dispersion of PTFE drops in the PBT matrix.

Wear Behavior of Polyester – Carbon Nanotubes Composites under Dry Sliding Ball-on-Flat Reciprocating Test

2015 ◽  
Vol 809-810 ◽  
pp. 1169-1174
Author(s):  
Adrian Cotet ◽  
Luminita Ciupagea ◽  
Dumitru Dima ◽  
Gabriel Andrei
Keyword(s):  
Carbon Nanotubes ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Wear Behavior ◽  
Multiwall Carbon Nanotubes ◽  
Dry Sliding ◽  
Linear Wear ◽  
Linear Wear Rate ◽  
Multiwall Carbon

Friction coefficient and linear wear rate of polyester-carbon nanotubes composites were investigated through ball-on-flat reciprocating test, under dry sliding contact. Three types of nanoscopic fillers were used: multiwall carbon nanotubes (MWCNT), functionalized multiwall carbon nanotubes (MWCNT-COOH) and singlewall carbon nanotubes (SWCNT), with three values of weight content 0.1, 0.15 and 0.2 wt%. Comparative analysis was done for polyester and its composites tested over 14 m sliding distance, under three values of load, 30 N, 40 N and 50 N. Composites containing MWCNT underwent a decrease in friction coefficient and linear wear rate only in case of 50N loading. An improvement of wear behavior under 50N loading was obtained for the composite with 0.10 wt% functionalized carbon nanotubes. Generally, better values of wear rate at 50 N loading were recorded in case of composites with 0.15 wt% and 0.20 wt% MWCNT and SWCNT, respectively. Optical and electronic investigation of the worn surfaces revealed the occurrence of abrasive, adhesive and fatigue wear. Abrasive wear is due to the hard particles detached from the counterpart which produce scratches and furrows on sliding track. Adhesive wear results when soft particle of polymer are caught and blocked among the asperities of counterpart, and it develops over a local area, being influenced by temperature rise. Fatigue and abrasive wear are responsible for the formation of the 3rd body between contacting parts which affects the friction and wear behavior. Morphological analysis of worn surface showed the rise of transfer film that induces instability of wear parameters.

scholarly journals Tribological Behavior of Polymers and Polymer Composites

2020 ◽  
Author(s):  
Lorena Deleanu ◽  
Mihail Botan ◽  
Constantin Georgescu
Keyword(s):  
Friction Coefficient ◽  
Tribological Behavior ◽  
Glass Beads ◽  
Linear Wear ◽  
Neat Polymer ◽  
Linear Wear Rate ◽  
Test Parameters ◽  
Order Of Magnitude ◽  
Contact Durability

This chapter means to explain the tribological behavior of polymer-based materials, to support a beneficial introducing of those materials in actual applications based on test campaigns and their results. Generally, the designers have to take into consideration a set of tribological parameters, not only one, including friction coefficient, wear, temperature in contact, contact durability related to application. Adding materials in polymers could improve especially wear with more than one order of magnitude, but when harder fillers are added (as glass beads, short fibers, minerals) the friction coefficient is slightly increased as compared to neat polymer. In this chapter, there are presented several research studies done by the authors, from which there is point out the importance of composite formulation based on experimental results. For instance, for PBT sliding on steel there was obtained a friction coefficient between 0.15 and 0.3, but for the composite with PBT + micro glass beads, the value of friction coefficient was greater. Adding a polymer playing the role of a solid lubricant (PTFE) in these composites and also only in PBT, decreased the friction coefficient till a maximum value of 0.25. The wear parameter, linear wear rate of the block (from block-on-ring tester) was reduced from 4.5 μm/(N⋅km) till bellow 1 μm/(N⋅km) for a dry sliding regime of 2.5…5 N, for all tested sliding velocities, for the composite PBT + 10% glass beads +10% PTFE, the most promising composite from this family of materials. This study emphasis the importance of polymer composite recipe and the test parameters. Also there are presented failure mechanisms within the tribolayer of polymer-based materials and their counterparts.

scholarly journals Influence of load and reinforcement content on selected tribological properties of Al/SiC/Gr hybrid composites

2018 ◽  
Vol 18 (18) ◽  
pp. 18-23 ◽  
Author(s):  
Sandra Veličković ◽  
Slavica Miladinović ◽  
Blaža Stojanović ◽  
Ružica R. Nikolić ◽  
Branislav Hadzima ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Metal Matrix ◽  
Hybrid Composites ◽  
Tribological Characteristics ◽  
Volume Fractions ◽  
Sic Particles ◽  
The Matrix

Abstract Hybrid materials with the metal matrix are important engineering materials due to their outstanding mechanical and tribological properties. Here are presented selected tribological properties of the hybrid composites with the matrix made of aluminum alloy and reinforced by the silicon carbide and graphite particles. The tribological characteristics of such materials are superior to characteristics of the matrix – the aluminum alloy, as well as to characteristics of the classical metal-matrix composites with a single reinforcing material. Those characteristics depend on the volume fractions of the reinforcing components, sizes of the reinforcing particles, as well as on the fabrication process of the hybrid composites. The considered tribological characteristics are the friction coefficient and the wear rate as functions of the load levels and the volume fractions of the graphite and the SiC particles. The wear rate increases with increase of the load and the Gr particles content and with reduction of the SiC particles content. The friction coefficient increases with the load, as well as with the SiC particles content increase.

Analysis of the Factors that Predispose to Wear with a 32mm Femoral Head at 5–15 Year follow-up: Clinical and Radiographic Assessment of the Harris-Galante cup at 5–15 Year follow-up

2003 ◽  
Vol 13 (2) ◽  
pp. 65-73
Author(s):  
M. Katsimihas ◽  
G. Katsimihas ◽  
M.B Lee ◽  
I. D. Learmonth
Keyword(s):  
Wear Rate ◽  
Polyethylene Wear ◽  
Young Patients ◽  
Harris Hip Score ◽  
Linear Wear ◽  
Outer Diameter ◽  
Linear Wear Rate ◽  
Total Hip Replacements ◽  
Hip Replacements

The clinical and radiographic features of 109 consecutive hybrid total hip replacements performed between 1986 and 1992 in 96 patients were retrospectively reviewed. A cementless Harris-Galante (HGP1) cup and a 32mm monobloc straight Muller stem were used in all cases. At an average 10.11 (range 5 to 15) years following surgery, the excellent durability of fixation of the Harris-Galante cup has been demonstrated with only one cup (0.9%) revised for periacetabular osteolysis and aseptic loosening. The prevalence of polyethylene wear was 27.4%. The mean annual linear wear rate was 0.063mm (range 0.00–0.53mm). There was a significantly increased wear of polyethylene inserts with an outer diameter < 52mm (<10mm polyethylene thickness), (ANOVA Test). However, there was no association found between acetabular liner wear and the following factors: underlying diagnosis, Charnley grade, age, weight and sex of the patient. The Harris Hip Score ranged between 5 and 54 pre-operatively and the average HHS was more than 80 post-operatively with more than 70% of patients pain-free. A liner with a thickness of 10mm or greater may prove beneficial in the prevention and reduction of wear rate particularly in young patients. It is recommended that all patients with this cup design, in which a polyethylene insert that is less than 10mm thick is coupled with a 32mm head, should continue to be regularly followed up.

In vitro comparison of the two hard-hard articulations for total hip replacements

2001 ◽  
Vol 215 (2) ◽  
pp. 153-160 ◽  
Author(s):  
C Rieker ◽  
R Konrad ◽  
R Schoun
Keyword(s):  
Wear Rate ◽  
Abrasive Wear ◽  
Experimental Methodology ◽  
Wear Behaviour ◽  
Linear Wear ◽  
Linear Wear Rate ◽  
Total Hip ◽  
Metal On Metal ◽  
In Vitro Comparison

Polyethylene particle disease is one of the major causes of late aseptic loosening of total hip replacement. Two hard-hard articulations (alumina-on-alumina and metal-on-metal) have been developed in Europe as an alternative to the ultra-high molecular weight polyethylene (UHMWPE) articulations. Even though these hard-hard articulations are on the market and numerous reports have been published about them, only a very limited number of studies allowing a direct in vitro comparison of the two articulations have been published so far. This paper compares in vitro these two types of articulation (alumina-on-alumina and metal-on-metal), which have been tested with a hip simulator for their tribological behaviour using exactly the same experimental methodology. This comparison shows that these two types of hard-hard articulation have very similar abrasive wear behaviour with four main features: 1. A running-in wear period (1 × 106 cycles) gives a cumulative wear of about 20 μm with head diameters of 28 mm. 2. After the running-in wear, there is a stabilization of the linear wear behaviour with a low linear wear rate/106 cycles for both types of articulation. 3. The volumetric wear rate of both articulations (<2.0 mm3/year for head diameters of 28mm) is significantly lower than that observed for metal-on-polyethylene or ceramic-on-polyethylene articulations having the same head diameter. 4. Abrasive wear is readily apparent (indicating a mixed lubrication regime) with both types of articulation. The extremely low wear performance of these articulations is confirmed and they constitute a lowwear alternative to the UHMWPE articulations currently used.

Study on the High-Heat Tribological Characteristics of Lubricating Wear-Resisting Coating Prepared by Supersonic Plasma Spraying

2011 ◽  
Vol 80-81 ◽  
pp. 661-666
Author(s):  
Yun Cai Zhao ◽  
Jia Jia Mao ◽  
Chun Ming Deng ◽  
Wem You Ma
Keyword(s):  
High Temperature ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Plasma Spraying ◽  
High Heat ◽  
The Self ◽  
Tribological Characteristics ◽  
Wear Properties ◽  
Abrasive Resistance ◽  
Supersonic Plasma

This paper is about the study of the KF301/WS2composite lubrication wear-resisting coatings prepared by supersonic plasma spraying. Basing on the research of the tribological characteristics, it has been discussed the self-lubricity and the failure mechanism showed by composite lubrication coatings under high-temperature conditions. Research shows that the wear rate of the coatings increased with the increase of the temperature. At 300°C, the wear rate is 1.02×10-4mg/m; At 750°C, the wear rate is 2.61×10-4mg/m. With the increase of temperature, friction coefficient of the coatings shows gradually increasing. When the temperature falls below 600°C, friction coefficient keeps around 0.08; At 750°C, the friction coefficient is 0.12. Temperature has great effect on the friction and wear properties ofthe self-lubricating wear-resisting coatings, mainly manifests in two aspects: first, with the increase of the temperature, under the common influence of thermal stress and frictional contact stress, it promotes the WS2solid lubricant film cracking, breakage, shedding process, and lubrication and abrasive resistance reduces; on the other hand, the WS2occurs chemical reaction under high temperature, generating lubricity phase of NiWO4, CrS, and lubricity phases are well supplied, lubricating film has an effect of continuous lubrication on the rubbing surface, So the coating shows low-friction, and it also represents that the KF-301/ WS2self-lubricating composite coating has good lubrication and abrasive resistance under high temperature．

Tribological Characteristics of Nickel-Aluminium Bronze CuAl10Ni5Fe4 against 30CrMnSiA Steel after the Prior Corrosion Treatment

2012 ◽  
Vol 201-202 ◽  
pp. 73-77 ◽  
Author(s):  
Zhi Hai Tan ◽  
Qiang Guo ◽  
Wen Kai Zhai ◽  
Zheng Ping Zhao
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Early Stage ◽  
Tribological Characteristics ◽  
Sliding Bearing ◽  
Short Period ◽  
Aluminium Bronze ◽  
Resistance Performance

The tribological characteristics of nickel-aluminium bronze CuAl10Ni5Fe4 against 30CrMnSiA steel after the prior corrosion treatment was studied at the M2000A model wear tester. The wear rate of corroded specimen was less than that of uncorroded specimen at the early stage of prior corrosion treatment, while the wear resistances deteriorated and the average friction coefficient slightly declined with the extension of prior corrosion period. The tests of CuAl10Ni5Fe4 sliding bearing at PLS-100 swing tribometer were used to validate the results. The wear resistances of CuAl10Ni5Fe4 sliding bearing increased slightly after a short period of prior corrosion, and the average friction coefficient decreased slightly after a long term of prior corrosion. A suitable period of prior corrosion treatment can enhance the wear resistance performance of CuAl10Ni5Fe4 bearing. The tribological characteristics of CuAl10Ni5Fe4 sliding bearing tested by PLS-100 rack swing tribometer are consistent with the conclusions of the tests at M2000A model wear tester.

Dry sliding of composites with PBT matrix and micro glass beads on steel

2014 ◽  
Vol 66 (3) ◽  
pp. 424-433 ◽  
Author(s):  
Constantin Georgescu ◽  
Lorena Deleanu ◽  
Mihail Botan
Keyword(s):  
Friction Coefficient ◽  
Tribological Behavior ◽  
Early Stage ◽  
Normal Load ◽  
Glass Beads ◽  
Polybutylene Terephthalate ◽  
Sem Images ◽  
Neat Polymer ◽  
Content Type ◽  
Sliding Distance

Purpose – This research aims to characterize the tribological behavior of polybutylene terephthalate (PBT) and PBT composites with micro glass beads (MGB) on steel, in dry conditions and on a block-on-ring tester, pointing out the influence of sliding distance and speed. The tribology of PBT and its composites is still in an early stage because this thermoplastic polyester requires accurate technological and thermal treatment. Design/methodology/approach – The composites were produced by ICEFS Savinesti Romania and contain PBT grade Crastin6130NC010 (as supplied by Du Pont), 0.5 […] 1.0 per cent (weight) Relamyd B-2Nf (polyamide grade produced by ICEFS, for a better dispersion of MGB), 1 per cent (weight) black carbon for technological and tribological reasons and different micro glass beads (MGB) concentrations (10.0 and 20.0 per cent weight). Tests were done for different sliding distances (2,500, 5,000 and 7,500 m) and speeds (0.5, 1.0 and 1.5 m/s) and a normal load of 5 N. Findings – The friction coefficient and the wear parameter (as mass loss of polymeric blocks) pointed out a good tribological behavior for these composites. Scanning electron microscope (SEM) images revealed particular aspects of PBT local transfer on steel. Also, 10 per cent MGB in PBT reduces wear, especially for longer distances (75,000 m) and higher speeds (0.5 and 0.75 m/s); the friction coefficient is only slightly increased up to 0.23, being less influenced by the speed and the sliding distance as compared to neat polymer. Originality/value – PBT and PBT composites could become challengers for replacing materials in applications similar to tested ones. Even the neat polymer exhibits a good tribological behavior. The composites have a lower sensibility to higher speeds and sliding distances for the applied load.

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