Polymer mechanics and tribology

2018 ◽  
Vol 70 (4) ◽  
pp. 764-772 ◽  
Author(s):  
Nikolai K. Myshkin ◽  
Alexander Kovalev
Keyword(s):  
Polymer Composites ◽  
Contact Mechanics ◽  
Tribological Behavior ◽  
Tribological Performance ◽  
Memory Storage ◽  
Polymer Mechanics ◽  
Micro Electro Mechanical Systems ◽  
Content Type ◽  
Storage Devices ◽  
Functional Additives

Purpose The purpose of this paper is to review the advances in mechanics and tribology of polymers and polymer-based materials. It is focused on the understanding of the correlation of contact mechanics and the tribological behavior of polymers and polymer composites by taking account of surface forces and adhesion in the contact. Design/methodology/approach Mechanical behavior of polymers is considered a viscoelasticity. Tribological performance is estimated while considering the parts of deformation and adhesion in friction arising in the contact. Surface energy, roughness, load and temperature effects on the tribological behavior of polymers are evaluated. Polymer composites produced by reinforcing and by the addition of functional additives are considered as materials for various applications in tribology. Particular attention is given to polymer-based nanocomposites. Findings A review of studies in tribology has shown that polymer-based materials can be most successfully used as self-lubricating components of sliding bearings. The use of the fillers provides changes in the tribological performance of neat polymers and widens their areas of application in the industry. Thin polymer films were found to be prospective lubricants for memory storage devices, micro-electro-mechanical systems and precision mechanisms. Further progress in polymer tribology should be achieved on solving the problems of contact mechanics, surface physics and tribochemistry by taking account of the scale factor. Originality/value The review is based on the experience of the authors in polymer mechanics and tribology, their research data and on data of many other literature sources published in this area. It can be useful for specialists in polymer research and industrial engineers working in tribology and industrial lubrication.

Bismuth (III) sulfide as additive: towards better lubricity without toxicity

2018 ◽  
Vol 70 (2) ◽  
pp. 347-352 ◽  
Author(s):  
Camila Müller ◽  
Franco Leonardo Redondo ◽  
Mariana Dennehy ◽  
Andrés Eduardo Ciolino ◽  
Walter Roberto Tuckart
Keyword(s):  
Green Chemistry ◽  
Design Methodology ◽  
Tribological Behavior ◽  
Environmentally Friendly ◽  
Tribological Performance ◽  
Extreme Pressure ◽  
Excellent Performance ◽  
Orthorhombic Crystal ◽  
Wear Area ◽  
Content Type

Purpose The purpose of this study is to design a fluid formulation with good lubricant properties by using an environmentally friendly additive for: high and low contact pressure conditions and steel/steel and polymer/steel systems. Design/methodology/approach Bismuth (III) sulfide (Bi2S3, “green chemistry” synthesis) is added to a commercial vinyl-terminated silicone fluid (PDMS-Vi) to obtain different weight-per cent mixtures. Tribological performance of formulations is studied from Reichert’s tests (steel/steel system) and block on ring tests (polymer/steel). The results are compared with formulations prepared with commercial bismuth (III) sulfide (Bi2S3), molybdenum (IV) sulfide (MoS2) and graphite. Findings An orthorhombic crystal lattice (XRD ) and a high-purity product (XRF) are evidenced for synthesized Bi2S3. Lubricant properties increase when the weight-per cent of the synthesized Bi2S3 increases in formulations. The wear area decreases up to 90 per cent according to Reichert’s tests. The synthesized Bi2S3 shows a better tribological behavior when compared to commercial Bi2S3, MoS2 and graphite. Originality/value Replacement of lead derivatives by an environmentally friendly lubricant in extreme pressure (EP) formulations and excellent performance compared to commercially used additives are achieved.

Tribological behavior of hybrid PTFE/Kevlar fabric composites with different weave densities

2016 ◽  
Vol 68 (2) ◽  
pp. 278-286 ◽  
Author(s):  
HuLin Li ◽  
Zhongwei Yin ◽  
Dan Jiang ◽  
YongJin Li
Keyword(s):  
Tribological Behavior ◽  
Three Dimensional ◽  
Bearing Steel ◽  
Tribological Performance ◽  
Elemental Content ◽  
Wear Volume ◽  
Dry Sliding ◽  
Content Type ◽  
Transfer Films ◽  
Fabric Composites

Purpose – The purpose of this paper is to achieve attractive fabric composites with excellent tribological performance and investigate the wear mechanisms of these fabric composites sliding against bearing steel pins under dry sliding process. Design/methodology/approach – Five different weave density composites were prepared, and the tribological behaviors of these composites were studied at different testing conditions. Scanning electron microscopy, laser microscopy (three-dimensional profile measurements) and energy-dispersive X-ray spectrometry were used to analyze the worn surface morphology, wear volume and elemental content of the transfer films, respectively. Findings – The composite weave density serves an important influence on tribological behavior. Generally, the wear rate of each composite increased with increasing weave density, and the friction coefficient of each composite decreased with increasing weave density. Originality/value – Nanoparticle-filled hybrid polytetrafluoroethylene/Kevlar fabric composites with proper weave density have exhibited superior tribological properties in dry sliding conditions. The results that obtained in this paper may offer a reference for others who intend to achieve attractive fabric composites with excellent tribological performance.

High-temperature tribological behavior of Mo and BaF2 added Cr3C2-NiCr matrix composite

2019 ◽  
Vol 72 (1) ◽  
pp. 136-145 ◽  
Author(s):  
Hailong Zhao ◽  
Lirong Luo ◽  
Fangwei Guo ◽  
Xiaofeng Zhao ◽  
Ping Xiao
Keyword(s):  
High Temperatures ◽  
Tribological Properties ◽  
Design Methodology ◽  
Wear Track ◽  
Tribological Behavior ◽  
Tribological Performance ◽  
Content Type ◽  
Plasma Sintering ◽  
Order Of Magnitude ◽  
Spark Plasma

Purpose The purpose of this paper is to investigate the tribological performance of Cr3C2–NiCr–Mo–BaF2 composite sliding against a Si3N4 ball at high temperatures. Design/methodology/approach A Cr3C2–NiCr composite and a Cr3C2–NiCr–Mo–BaF2 composite were prepared using spark plasma sintering. Tribological properties of the composites were investigated using a ball-on-disk type tribotester. The relationships among the microstructure, wear mechanism and tribological performance were determined by analyzing the wear track morphologies and the glaze layer’s phase composition. Findings The wear rate of the Cr3C2–NiCr–Mo–BaF2 composite was approximately one order of magnitude lower than that of the Cr3C2–NiCr composite from 700°C to 900°C when sliding against a Si3N4 ball. The favorable tribological performance of the Cr3C2–NiCr–Mo–BaF2 composite at high temperatures results from the synergistic lubrication of MoOx, BaF2 and BaMoO4. Originality/value This paper reports a new Cr3C2–NiCr matrix self-lubricating composite with better tribological properties than Cr3C2–NiCr composite at temperatures up to 900°C through Mo and BaF2 addition.

scholarly journals A review of the bio-tribology of medical devices

Friction ◽  
2021 ◽  
Author(s):  
Xiaogang Zhang ◽  
Yali Zhang ◽  
Zhongmin Jin
Keyword(s):  
Service Life ◽  
Medical Devices ◽  
Tribological Behavior ◽  
Tribological Performance ◽  
Dental Restoration ◽  
Surgical Instruments ◽  
Cardiovascular Devices ◽  
Artificial Joints ◽  
Future Developments ◽  
Fixation Devices

AbstractNumerous medical devices have been applied for the treatment or alleviation of various diseases. Tribological issues widely exist in those medical devices and play vital roles in determining their performance and service life. In this review, the bio-tribological issues involved in commonly used medical devices are identified, including artificial joints, fracture fixation devices, skin-related devices, dental restoration devices, cardiovascular devices, and surgical instruments. The current understanding of the bio-tribological behavior and mechanism involved in those devices is summarized. Recent advances in the improvement of tribological properties are examined. Challenges and future developments for the prospective of bio-tribological performance are highlighted.

scholarly journals Implications of NVM Based Storage on Memory Subsystem Management

2020 ◽  
Vol 10 (3) ◽  
pp. 999
Author(s):  
Hyokyung Bahn ◽  
Kyungwoon Cho
Keyword(s):  
Random Access ◽  
Disk Drive ◽  
Main Memory ◽  
Memory Storage ◽  
Storage Device ◽  
Storage Devices ◽  
Large Memory ◽  
Memory Subsystems ◽  
Non Volatile Memory ◽  
Management Techniques

Recently, non-volatile memory (NVM) has advanced as a fast storage medium, and legacy memory subsystems optimized for DRAM (dynamic random access memory) and HDD (hard disk drive) hierarchies need to be revisited. In this article, we explore the memory subsystems that use NVM as an underlying storage device and discuss the challenges and implications of such systems. As storage performance becomes close to DRAM performance, existing memory configurations and I/O (input/output) mechanisms should be reassessed. This article explores the performance of systems with NVM based storage emulated by the RAMDisk under various configurations. Through our measurement study, we make the following findings. (1) We can decrease the main memory size without performance penalties when NVM storage is adopted instead of HDD. (2) For buffer caching to be effective, judicious management techniques like admission control are necessary. (3) Prefetching is not effective in NVM storage. (4) The effect of synchronous I/O and direct I/O in NVM storage is less significant than that in HDD storage. (5) Performance degradation due to the contention of multi-threads is less severe in NVM based storage than in HDD. Based on these observations, we discuss a new PC configuration consisting of small memory and fast storage in comparison with a traditional PC consisting of large memory and slow storage. We show that this new memory-storage configuration can be an alternative solution for ever-growing memory demands and the limited density of DRAM memory. We anticipate that our results will provide directions in system software development in the presence of ever-faster storage devices.

Computational contact mechanics analysis of laterally graded orthotropic half-planes

2017 ◽  
Vol 14 (2) ◽  
pp. 145-154 ◽  
Author(s):  
Onur Arslan
Keyword(s):  
Contact Mechanics ◽  
Solution Method ◽  
Solution Procedure ◽  
Engineering Applications ◽  
Linear Solution ◽  
Content Type ◽  
Analytical Technique ◽  
Computational Contact Mechanics ◽  
Mechanics Analysis ◽  
Contact Response

Purpose Frictional sliding contact problems between laterally graded orthotropic half-planes and a flat rigid stamp are investigated. The presented study aims at guiding engineering applications in the prediction of the contact response of orthotropic laterally graded members. Design/methodology/approach The solution procedure is based on a finite element (FE) approach which is conducted with an efficient FE analysis software ANSYS. The spatial gradations of the orthotropic stiffness constants through the horizontal axis are enabled utilizing the homogeneous FE approach. The Augmented Lagrangian contact algorithm is used as an iterative non-linear solution method in the contact analysis. Findings The accuracy of the proposed FE solution method is approved by using the comparisons of the results with those computed using an analytical technique. The prominent results indicate that the surface contact stresses can be mitigated upon increasing the degree of orthotropy and positive lateral gradations. Originality/value One can infer from the literature survey that, the contact mechanics analysis of orthotropic laterally graded materials has not been investigated so far. In this study, an FE method-based computational solution procedure for the aforementioned problem is addressed. The presented study aims at guiding engineering applications in the prediction of the contact response of orthotropic laterally graded members. Additionally, this study provides some useful points related to computational contact mechanics analysis of orthotropic structures.

scholarly journals Erratum: Investigation on mechanical and tribological behavior of naturally woven coconut sheath-reinforced polymer composites

2015 ◽  
Vol 38 (7) ◽  
pp. 1492-1492 ◽  
Author(s):  
Irullappasamy Siva ◽  
Jebas Thangiah Winowlin Jappes ◽  
Bheemappa Suresha
Keyword(s):  
Polymer Composites ◽  
Tribological Behavior ◽  
Reinforced Polymer

Tribological performance of self-lubricated polyamide6/boric oxide composites after water conditioning

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kawaljit Singh Randhawa ◽  
Ashwin Patel
Keyword(s):  
Friction Coefficient ◽  
Abrasion Resistance ◽  
Tribological Performance ◽  
Boric Oxide ◽  
Resistance Testing ◽  
Tribological Behaviour ◽  
Content Type ◽  
Wear Rates ◽  
Water Conditioning ◽  
Oxide Composites

Purpose This paper aims to investigate the tribological performance, i.e. abrasion resistance, friction coefficient and wear rates, of self-lubricated water conditioned polyamide6/boric oxide composites. Design/methodology/approach Polyamide6 and polyamide6/boric oxide self-lubricated composites were immersed in water for 15 days to analyze the effect of water conditioning on friction, wear and abrasion resistance. Tribological testing on pin-on-disc tribometer and abrasion resistance testing on TABER abrader were performed to see the friction coefficient and wear rates of materials. The scanning electron microscopy (SEM) characterizations were performed to analyze the wear tracks. Findings Tribological testing results revealed the loss in abrasive resistance, but there was an improvement in frictional coefficient and wear rates with steel after water absorption. The SEM images clearly show less depth of wear tracks in water-conditioned materials than dry ones. Water conditioning was found supportive in the formation of smooth lubricating transfer film on steel disc during the tribological testing. Originality/value The tribological behaviour of polymer composites is different in dry and in high humidity or water conditions. Experiments were performed to investigate B2O3 solid lubricant filler effectiveness on tribological behaviour of water-conditioned polyamide composites. Bonding between polyamide6 and water molecules plus the formation of orthoboric acid was found advantageous in decreasing the friction coefficient and wear rates of composites.

A self-developed indoor three-dimensional pedestrian localization platform based on MEMS sensors

Sensor Review ◽  
2015 ◽  
Vol 35 (2) ◽  
pp. 157-167 ◽  
Author(s):  
Shengbo Sang ◽  
Ruiyong Zhai ◽  
Wendong Zhang ◽  
Qirui Sun ◽  
Zhaoying Zhou
Keyword(s):  
Low Cost ◽  
Angular Rate ◽  
Three Dimensional ◽  
Dead Reckoning ◽  
Rate Data ◽  
Mems Sensors ◽  
Micro Electro Mechanical Systems ◽  
Content Type ◽  
Position Errors ◽  
Low Performance

Purpose – This study aims to design a new low-cost localization platform for estimating the location and orientation of a pedestrian in a building. The micro-electro-mechanical systems (MEMS) sensor error compensation and the algorithm were improved to realize the localization and altitude accuracy. Design/methodology/approach – The platform hardware was designed with common low-performance and inexpensive MEMS sensors, and with a barometric altimeter employed to augment altitude measurement. The inertial navigation system (INS) – extended Kalman filter (EKF) – zero-velocity updating (ZUPT) (INS-EKF-ZUPT [IEZ])-extended methods and pedestrian dead reckoning (PDR) (IEZ + PDR) algorithm were modified and improved with altitude determined by acceleration integration height and pressure altitude. The “AND” logic with acceleration and angular rate data were presented to update the stance phases. Findings – The new platform was tested in real three-dimensional (3D) in-building scenarios, achieved with position errors below 0.5 m for 50-m-long route in corridor and below 0.1 m on stairs. The algorithm is robust enough for both the walking motion and the fast dynamic motion. Originality/value – The paper presents a new self-developed, integrated platform. The IEZ-extended methods, the modified PDR (IEZ + PDR) algorithm and “AND” logic with acceleration and angular rate data can improve the high localization and altitude accuracy. It is a great support for the increasing 3D location demand in indoor cases for universal application with ordinary sensors.

Preparation of the polymerizable titania oriented to 3D printing and the laser-induced crystallization

2018 ◽  
Vol 24 (9) ◽  
pp. 1421-1427 ◽  
Author(s):  
Feng Liu ◽  
Shaoai Xie ◽  
Yan Wang ◽  
Jianjun Yu ◽  
Qinghua Meng
Keyword(s):  
3D Printing ◽  
Sol Gel ◽  
Crystal Form ◽  
Tetrabutyl Titanate ◽  
Content Type ◽  
Functional Additives ◽  
Sol Gel Process ◽  
Photosensitive Resin ◽  
Induced Crystallization

PurposeThe titania (titanium dioxide) is one of the important functional additives in the photosensitive resin and encounters the problem of stabilization in the photosensitive resin for 3D printing. This study aims to achieve enhancement in stabilization by preparation of the polymerizable titania andin situlaser-induced crystallization during 3D printing.Design/methodology/approachA type of polymerizable titania (AAEM@TiO2) was designed and prepared from tetrabutyl titanate (TBT) and 2-(acetoacetoxy)ethyl methacrylate (AAEM) via the sol–gel process, which was characterized by Fourier-transform infrared (FTIR) spectra, ultraviolet–visible (UV-Vis) spectra, surface bonding efficiency (SBE) and settling height (H). AAEM acted on both bonding to the titania and polymerization with the monomer in resin for stabilization. The polymerizable titania could be converted to the pigmented titania by means of laser-induced crystallization. The photosensitive resin was then formulated on the basis of optimization and used in a stereolithography apparatus (SLA) for 3D printing.FindingsThe stabilization effect of AAEM on TiO2was achieved and the mechanism of competition in the light-consuming reactions during photocuring was proposed. The ratio of nAAEM/nTBTin AAEM@TiO2, the concentration of AAEM@TiO2and photoinitiator (PI) used in the photosensitive resin were optimized. The anatase crystal form was indicated by X-ray diffraction (XRD) and clustering of nanocrystals was revealed by scanning electron microscopy (SEM) after SLA 3D printing.Originality/valueThis investigation provides a novel method of pigmentation by preparation of the polymerizable titania andin situlaser-induced crystallization for SLA 3D printing.

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