Physico-mechanical, thermal, and tribological studies of polytetrafluoroethylene-filled polyoxymethylene/silicone composites

2020 ◽  
pp. 089270572092511
Author(s):  
MR Shankare Gowda ◽  
AB Hemavathi ◽  
S Srinivas ◽  
G Santhosh ◽  
Hatna Siddaramaiah
Keyword(s):  
Impact Strength ◽  
Friction And Wear ◽  
Room Temperature ◽  
Wear Behavior ◽  
Transfer Film ◽  
Negative Effects ◽  
Wear Performance ◽  
Mating Surface ◽  
Injection Molded ◽  
Ptfe Composites

Polyoxymethylene (POM)-based composites with polytetrafluoroethylene (PTFE) filler and silicone gum have been prepared by melt extrusion to enhance the wear resistance and friction lubrication of POM without compromising the other desired properties such as modulus, toughness/impact strength, notch insensitivity, and thermal stability. The compounded material was injection molded to prepare test specimens, and their physico-mechanical properties were evaluated. In addition, thermal and tribological characteristics of the composites were also studied. The addition of silicone into POM/PTFE composites could enhance the formation of stable transfer film on the mating surface during sliding contact, thus improving the friction and wear performance, as silicone forms synergistic mixture with PTFE. It was found that the tensile, flexural, and notched impact strength remained almost constant for all the formulations. The use of PTFE improved the unnotched impact strength (from 35.5 to 42.9 kJ m−2). The toughening effect can be attributed to the dissipation of impact energy through soft PTFE and ductile silicone phase. Differential scanning calorimeter results revealed that there are no negative effects on POM crystallinity due to the presence of PTFE and silicone. The wear behavior of composites has been investigated under dry sliding conditions at different normal loads and sliding velocities at room temperature. The POM/PTFE/silicone (90/8/2 wt/wt%) formulation exhibits better wear-resistant behavior in the present study.

High-Temperature Wear Mechanisms of a Severely Plastic Deformed Al/Mg2Si Composite

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Mahsa Ebrahimi ◽  
Abbas Zarei-Hanzaki ◽  
A. H. Shafieizad ◽  
Michaela Šlapáková ◽  
Parya Teymoory
Keyword(s):  
Plastic Deformation ◽  
Room Temperature ◽  
Wear Behavior ◽  
Normal Load ◽  
Aluminum Matrix ◽  
Hardened Layer ◽  
Dry Sliding Wear ◽  
Wear Properties ◽  
Wear Performance ◽  
Processed Material

The present work was primarily conducted to study the wear behavior of as-received and severely deformed Al-15%Mg2Si in situ composites. The severe plastic deformation was applied using accumulative back extrusion (ABE) technique (one and three passes). The continuous dynamic recrystallization (CDRX) was recognized as the main strain accommodation and grain refinement mechanism within aluminum matrix during ABE cycles. To investigate the wear properties of the processed material, the dry sliding wear tests were carried out on both the as-received and processed samples under normal load of 10 and 20 N at room temperature, 100 °C, and 200 °C. The results indicated a better wear resistance of processed specimens in comparison to the as-received ones at room temperature. In addition, the wear performance was improved as the ABE pass numbers increased. These were related to the presence of oxide tribolayer. At 100 °C, the as-received material exhibited a better wear performance compared to the processed material; this was attributed to the formation of a work-hardened layer on the worn surface. At 200 °C, both the as-received and processed composites experienced a severe wear condition. In general, elevating the temperature changed the dominant wear mechanism from oxidation and delamination at room temperature to severe adhesion and plastic deformation at 200 °C.

The Friction and Wear of Thin, Sintered, Fluoride Films

1972 ◽  
Vol 94 (1) ◽  
pp. 12-18 ◽  
Author(s):  
M. T. Lavik ◽  
B. D. McConnell ◽  
G. David Moore
Keyword(s):  
Friction Coefficient ◽  
Friction And Wear ◽  
Room Temperature ◽  
Wear Behavior ◽  
Strong Dependence ◽  
Aluminum Phosphate ◽  
Friction And Wear Behavior ◽  
Wear Life ◽  
Compositional Changes ◽  
Cure Temperature

Results are presented for the bonding of thin, sintered, fluoride films of BaF2 and CaF2 with mono-aluminum phosphate. Friction and wear behavior of these films has been defined in terms of film compositional changes, film curing procedures, and substrate variations when subjected to varying levels of temperature and load. Mono-aluminum phosphate was found to greatly enhance the adhesion of the sintered fluoride film. There was a strong dependence of wear life at 1000 deg F on the mono-aluminum phosphate content of the film. Films containing 6 vol. percent phosphate appear to be near optimum and exhibited wear lives of 1,000,000 load cycles under sliding conditions in a dual rub-shoe device with friction coefficient levels in the order of 0.10 to 0.20. Near-optimum values were determined for cure temperature (950 deg C), and surface finish (23 μ in. rms) on rhodium-plated substrates. Graphite and gold were added to the aluminum phosphate bonded BaF2: CaF2 films. Both additives were found to lower the friction coefficient at room temperature.

Study on the Friction and Wear Behavior of Grind-Hardened Layer

2010 ◽  
Vol 431-432 ◽  
pp. 385-388 ◽  
Author(s):  
Jian Hua Zhang ◽  
Pei Qi Ge ◽  
Lei Zhang ◽  
Yang Yu ◽  
Hui Li
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Wear Debris ◽  
Friction And Wear ◽  
Wear Behavior ◽  
Hardened Layer ◽  
Hardened Steel ◽  
Wear Performance ◽  
Friction And Wear Behavior ◽  
Grind Hardening

The grind-hardening technology utilizes the grinding heat to harden the surface of the workpiece. The friction and wear performance of the grind-hardened layer is one of the important parameters. In this paper, the friction and wear performance of the grind-hardened layer was studied by the friction and wear experiment. The wear rate and the friction coefficient of the grind-hardened steel were studied by comparing with conventional hardened steel and non-hardened steel. The surface worn morphology and the collected wear debris of the grind-hardened steel were observed during the experiment. The wear mechanism of the grind-hardened steel was analyzed under different friction conditions.

HIGH-TEMPERATURE TRIBOLOGICAL BEHAVIORS OF TiNi/Ti2Ni ALLOYED LAYER ON SURFACE OF Ti6Al4V ALLOY

2017 ◽  
Vol 24 (03) ◽  
pp. 1750028 ◽  
Author(s):  
ZHENXIA WANG ◽  
HAIRUI WU ◽  
NAIMING LIN ◽  
XIAOHONG YAO ◽  
ZHIYONG HE ◽  
...  
Keyword(s):  
High Temperature ◽  
Friction Coefficient ◽  
Friction And Wear ◽  
Room Temperature ◽  
Alloyed Layer ◽  
Surface Alloying ◽  
Wear Performance ◽  
Ti6al4v Substrate ◽  
Oxidation Wear ◽  
Plasma Surface Alloying

Plasma surface alloying (PSA) technique was employed with nickel as incident ions to prepare the TiNi/Ti2Ni alloyed layer on surface of Ti6Al4V. High-temperature friction and wear performance of TiNi/Ti2Ni alloyed layer and the Ti6Al4V substrate were evaluated at 500[Formula: see text]C. The results indicated that the TiNi/Ti2Ni alloyed layer exhibited superior high-temperature wear performance. The variations of friction coefficient were the same rule but wear rate was lower compared to Ti6Al4V substrate. The wear mechanism of TiNi/Ti2Ni alloyed layer was mainly slight abrasion and the Ti6Al4V substrate showed abrasion and oxidation wear. The friction coefficient of the TiNi/Ti2Ni alloyed layer decreased from 0.90 to 0.50 with the increase of temperature from room temperature to 500[Formula: see text]C.

The effect of colemanite on the friction performance of automotive brake friction materials

2016 ◽  
Vol 68 (1) ◽  
pp. 92-98 ◽  
Author(s):  
ilker Sugozu ◽  
ibrahim mutlu ◽  
Kezban Banu Sugozu
Keyword(s):  
Friction Coefficient ◽  
Friction And Wear ◽  
Negative Effects ◽  
Wear Performance ◽  
Industrial Firms ◽  
Friction Materials ◽  
Content Type ◽  
Friction Performance ◽  
Brake Lining ◽  
Automotive Brake

Purpose – The purpose of this paper is to investigate use of colemanite (C) upon friction and wear performance of automotive brake lining. Brake lining production with the boron product colemanite addition and braking characterization investigated for development of non-asbestos organic (NAO) brake lining because of negative effects on human health and environmental hazard of asbestos containing linings. During the braking, brake lining is warmed up extremely due to friction, and the high temperature causes to decreasing of breaking performance. Colemanite has high melting temperature, and this makes this material valuable for brake lining. Design/methodology/approach – This study investigated the effect of colemanite (C) upon friction and wear performance of automotive brake lining. Based on a simple experimental formulation, different amounts of boron product colemanite were used and then evaluated using a friction assessment and screening test. In these specimens, half of the samples (shown with H indices) were heat treated in 4 h at 180°C temperature. Friction coefficient, wear rate and scanning electron microscope for friction surfaces were used to assess the performance of these samples. Findings – The results of test showed that colemanite can substantially improve properties of friction materials. The friction coefficient of friction materials modified with colemanite varies steadily with the change of temperature, and the wearing rate of friction materials is relatively low by using colemanite. Heat treatment-applied samples (CH) have provided a higher and stable friction coefficient. These results indicate that colemanite has ideal application effect in various friction materials. Originality/value – This paper fulfils an identified information and offers practical help to the industrial firms working with brake lining and also to the academicians working on wear of materials. Parallel results have been presented between previously reported and present study, in view of brake characteristics and wear resistance. Use of the lower cost and productive organic sources of material are the main improvement of the present study.

Dry sliding friction and wear behavior of self-lubricating wollastonite filled polycarbonate composites

2015 ◽  
Vol 67 (1) ◽  
pp. 22-29 ◽  
Author(s):  
Akin Akinci
Keyword(s):  
Wear Rate ◽  
Friction And Wear ◽  
Sliding Friction ◽  
Wear Behavior ◽  
Xrd Analysis ◽  
Dry Sliding ◽  
Wear Performance ◽  
Content Type ◽  
Wear Rates ◽  
Wear Tests

Purpose – The purpose of this paper is to investigate the friction and wear performance of pure polycarbonate (PC) and 5-30 per cent wollastonite-filled (by weight) PC were comparatively evaluated under dry sliding conditions. Wear tests were carried out at room temperature under the loads of 5-20 N and at the sliding speeds of 0.5-1.5 m/s. Design/methodology/approach – The microstructures of the wollastonite, pure PC and composites were examined by optical microscopy, scanning electron microscopy, energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analysis. The friction and wear tests were realized using a pin-on-disk arrangement against the hardened AISI 4140 steel. Findings – The result of this study indicated that the coefficients of friction wear rate of the materials were significantly influenced by an increase in wollastonite content. The friction coefficient of the PC was getting decreased from 0.457 to 0.198 with an increase in wollastonite content, depending on applied loads and sliding speeds. On the other hand, the results showed that the wear rates of pure PC and wollastonite-filled PCs decreased with an increase in loads. The wear rate of the PC decreased from 1.2 × 10−6 to 8.7 × 10−6 mm3/m with an increase in wollastonite content, depending on applied loads. Originality/value – There are many reports which deal with the friction and wear performance of the polymers and polymer composites. However, the effect of wollastonite effect on tribological performance of PC has up to now not been extensively researched.

The effects of filler type on the friction and wear performance of PEEK and PTFE composites under hybrid wear conditions

Wear ◽  
2021 ◽  
pp. 204178
Author(s):  
Zhibin Lin ◽  
Ke Zhang ◽  
Jiaxin Ye ◽  
Xiangji Li ◽  
Xiaogang Zhao ◽  
...  
Keyword(s):  
Friction And Wear ◽  
Wear Performance ◽  
Ptfe Composites
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