scholarly journals Tribology of Polymer Blends PBT + PTFE

Author(s):  
Constantin Georgescu ◽  
Lorena Deleanu ◽  
Larisa Chiper (Titire) ◽  
Alina Cantaragiu Ceoromila

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.

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 997
Author(s):  
Constantin Georgescu ◽  
Lorena Deleanu ◽  
Larisa Chiper Titire ◽  
Alina Cantaragiu Ceoromila

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.


2014 ◽  
Vol 66 (3) ◽  
pp. 424-433 ◽  
Author(s):  
Constantin Georgescu ◽  
Lorena Deleanu ◽  
Mihail Botan

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.


2018 ◽  
Vol 18 (18) ◽  
pp. 18-23 ◽  
Author(s):  
Sandra Veličković ◽  
Slavica Miladinović ◽  
Blaža Stojanović ◽  
Ružica R. Nikolić ◽  
Branislav Hadzima ◽  
...  

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.


Author(s):  
Aravind Dhandapani ◽  
Senthilkumar Krishnasamy ◽  
Thitinun Ungtrakul ◽  
Senthil Muthu Kumar Thiagamani ◽  
Rajini Nagarajan ◽  
...  

Tribology, which may be defined as an interdisciplinary subject, deals with relative motion between two or more bodies, i.e., surfaces that are interacting relatively. Thus, tribology is a science covering three vital classes, namely, 1) wear, 2) friction, and 3) lubrication. The focus of this article is to bring out the elements that are influencing the wear-resisting behavior of thermosetting and thermoplastic composites with natural-based constituents. It was also identified from the literature sources that 1) the treatments on the natural fibers acting as reinforcement and 2) the addition of fillers in resin acting as matrix could improve the wear-resisting behavior of the composites. Additionally, other conditions such as 1) sliding speed, 2) sliding velocity, 3) sliding distance, and 4) operating temperature could also influence the friction coefficient and specific wear rate of the natural-based composites.


2009 ◽  
Vol 16 (03) ◽  
pp. 407-414 ◽  
Author(s):  
B. F. YOUSIF ◽  
ALVIN DEVADAS ◽  
TALAL F. YUSAF

In the current study, a multilayered polyester composite based on betelnut fiber mats is fabricated. The adhesive wear and frictional performance of the composite was studied against a smooth stainless steel at different sliding distances (0–6.72 km) and applied loads (20–200 N) at 2.8 m/s sliding velocity. Variations in specific wear rate and friction coefficient were evaluated at two different orientations of fiber mat; namely parallel (P–O) and normal (N–O). Results obtained were presented against sliding distance. The worn surfaces of the composite were studied using an optical microscope. The effect of the composite sliding on the stainless steel counterface roughness was investigated. The results revealed that the wear performance of betelnut fiber reinforced polyester (BFRP) composite under wet contact condition was highly dependent on test parameters and fiber mat orientation. The specific wear rate performance for each orientation showed an inverse relationship to sliding distance. BFRP composite in N–O exhibited better wear performance compared with P–O. However, the friction coefficient in N–O was higher than that in P–O at lower range of applied load. The predominant wear mechanism was debonding of fiber with no pullout or ploughing. Moreover, at higher applied loads, micro- and macrocracking and fracture were observed in the resinous region.


2014 ◽  
Vol 658 ◽  
pp. 283-288 ◽  
Author(s):  
Mihail Botan ◽  
Constantin Georgescu ◽  
Lorena Deleanu

This paper presents a comparative study upon tribological behavior of polybutylene terephthalate (PBT) and a blend of PBT + This paper presents a comparative study upon tribological behavior of polybutylene terephthalate (PBT) and a blend of PBT + 10% aramid fibers, in dry regime. Some of the properties of PBT grade CRASTIN 6130 NC010®. The tested materials they were obtained by molding at ICEFS Savinesti Romania. The aramid fibers added into PBT were supplied by Teijin, and have an average length of 125 mm. Tests were done with the help of a block-on-ring tribotester. The tests parameters were: three normal forces (F = 5 N, F = 15 N and F = 30 N), three values of sliding speed (v = 0.25 m/s, v = 0.50 m/s and v = 0.75 m/s) and a sliding distance of L = 5000 m, in dry regime, each test characterized by (F, v, L) being done twice. The conclusion of this research was that adding short aramid fibers in PBT improves the wear resistance, but slightly increases the friction coefficient. Also, the recorded temperatures near the contact are higher for the blend with aramid fibers. SEM investigation revealed particular processes within superficial layers of polymeric blend.


2011 ◽  
Vol 80-81 ◽  
pp. 661-666
Author(s):  
Yun Cai Zhao ◽  
Jia Jia Mao ◽  
Chun Ming Deng ◽  
Wem You Ma

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.


2012 ◽  
Vol 201-202 ◽  
pp. 73-77 ◽  
Author(s):  
Zhi Hai Tan ◽  
Qiang Guo ◽  
Wen Kai Zhai ◽  
Zheng Ping Zhao

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.


2005 ◽  
Vol 290 ◽  
pp. 276-279
Author(s):  
Miriam Kupková ◽  
Martin Kupka ◽  
Emőke Rudnayová ◽  
Ján Dusza

Irregular evolution of friction coefficient, recorded during the ball-on-disc test on Si3N4 based ceramic materials, was analysed by means of fractal geometry methods. Tests were carried out at room temperature, in air and without any lubricant. It was proven that the friction coefficient trace, considered as a geometric object, has the property of a fractal curve. The fractal dimension of this curve increased with increasing wear rate measured in a corresponding wear test. This could indicate the possible correlation between the wear rate and the fractal dimension of friction coefficient as a function of sliding distance (time).


2011 ◽  
Vol 338 ◽  
pp. 603-606
Author(s):  
Zhen Hui Luan ◽  
Ming Ding ◽  
Xiang Fei Wu

As friction pair, ZCuPb20Sn5 and No.45 steel are most in use in gear motor under oil lubrication. In order to investigate the tribological characteristics of ZCuPb20Sn5 and No.45 steel under emulsion lubrication, the authers tested them on MMW-1 friction and wear tester with sample pin and thrust ring. The relationships between the friction coefficient and the load, the friction coefficient and the speed, the wear rate and the load, the wear rate and the speed were provided. The worn surface of ZCuPb20Sn5 were investigated by means of scanning electron microscope. The results showed that, alone with the raising of the load and the speed, the wear rate of ZCuPb20Sn5 increased, but the friction coefficient reduced.


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