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Influence of Carbon Particle in Polymer Matrix Composite over Mechanical Properties and Tribology Behavior

Sravanthi K., Mahesh V., Nageswara Rao Boggarapu

Archives of Metallurgy and Materials

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2021

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Vol. 66, iss. 4

1171--1178

EN

In this research, the carbon particle dispersions are made in two different levels as carbon nano tube (CNT) and carbon particle in microns range. The mechanical strength is evaluated for the composites developed by axial loading and bending test analysis. In addition, the air jet abrasive particle erosion study is performed for different angle of impingement. The dispersion of carbon particle in the matrix material has reduced the mechanical strength. The sample with 4% of CNT dispersion in the composite has a maximum strength of 143 MPa and a minimum strength of 112 MPa. For the same combination (4% of CNT composite), the maximum flexural strength is 116 MPa. It is clear to infer that the strength of CNT in matrix materials is superior to the increase in length of carbon particle. The dispersion of carbon particle in the matrix material increases the brittleness and the strength is diminished. During the flexural bending, the fiber delamination occurred with severe deformation in the plain composite. When the materials are subjected to impingement of solid particle, the attrition effect on the exposed surfaces is vulnerable towards erosive mechanism. The presence of carbon in the matrix material has significantly increased the surface property. The results are appreciable for 4% of CNT composite. Especially at 30º, the minimum erosive wear 0.0033 g/g has been recorded. Erosive wear is less at minimum impingement angle and the wear is found increasing at higher impingement angle. Therefore, it is recommended not to add carbon particle to a higher weight percentage, since it leads to brittleness.

2

Enhancement of tribological properties and characteristic of polymer matrix composite (UHMWPE reinforced with short fibres of polyester) for Total Disc Replacement (TDR)

Obaid M. N., Radhi S. H.

Journal of Achievements in Materials and Manufacturing Engineering

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2020

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Vol. 102, nr 2

55--65

EN

Purpose: The number of people suffering from Degenerative Disc Disease (DDD) is increasing. The disease causes heavy pain and restrict a number of day-to-day life activities. In extreme cases, the degraded disc is removed under total disc replacement which is usually made up of Ultra-High Molecular Weight Polyethylene (UHMWPE). The material has astounding biocompatible characteristics mechanical properties and wear resistance. However, these characteristics are insufficient in arthroplasty application. Therefore, research investigations are ongoing to improve tribological properties through reinforcement that may result in a composite material of UHMWPE. Thus the current study is aimed at reinforcing UHMWPE with short fibres of polyesters to enhance the tribological properties and surface characteristic so as to improve wear resistance and nourish the fibroblast cells on synthetic disc. Design/methodology/approach: The researcher prepared UHMWPE composite material, reinforced with different weight fractions of short polyester fibres (2, 4, 6, 8 and 10% following hot press method. Further pin-on-disc device was used to study the tribological properties (coefficient of friction and volume of wear). The study tested surface roughness and surface characteristics by atomic force microscopy (AFM) device, hardness by shore D device, contact angle to study the effect of polyester short fibres on wettability of UHMWPE surface and tested the thermal properties and crystalline degree using Differential Scanning Calorimetry measurement (DSC) device. Findings: The results infer that the wear resistance got improved when using 2% w.t polyester though it got decreased initially. However, the value was still more than neat UHMWPE. There was a decrease observed in coefficient of friction, but after 4 w.t% polyester, the coefficient of friction got increased due to increasing percentage of fibres which make it harder and stiff compared to UHMWPE. There was a decline observed in surface roughness due to alignment of the fibres with smooth surface. The contact angle got increased in a moderate range while the roughness enhanced the growth of fibroblast cell. The hardness of composite material got increased, because the fibres turned stiffer and harder than the matrix. DSC results infer the improvements in thermal stability due to high thermal properties of polyester fibres compared to UHMWPE. The degree of crystallinity got increased which in turn enhanced wear resistance, especially at 6 w.t % polyester fibres. There was a mild increase observed in density since the density of polyester is higher than polymer. Research limitations/implications: The major challenge was the dispersion of fibres. Uniform distribution of fibres within the matrix (UHMWPE) was achieved through two steps of mixing processes such as mechanical mixture and twin extruder. In future studies, fatigue tests must be conducted to study the behaviour of prepared composite materials under fatigue cycle. Practical implications: A significant objective is how to connect among different properties to obtain good improvement in tribological and surface properties so as to enhance wear resistance and growth of fibrolase cells. Originality/value: In this study, polymeric short fibres were used as reinforcement with polymeric matrix to enhance the wettability of fibres with matrix. In this way, the bonding among them got increased which supports the tribological, surface, and crystalline behaviour.

3

Materiały stosowane w napędach ciernych oraz metody ich badań

Porąbka A., Blicharski M., Laska J.

Transport Przemysłowy i Maszyny Robocze

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2012

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Nr 2

72--79

PL

Tribologia połączeń mechaniczno-dynamicznych jest określana jako nauka o oddziałujących ze sobą i będących we wzajemnym ruchu powierzchniach. Ruch jednej powierzchni ciała stałego względem drugiej jest istotny dla funkcjonowania wielu rodzajów mechanizmów, ponieważ w maszynach znajduje się wiele części składowych, które pracując, trą o siebie. W niektórych przypadkach tarcie pomiędzy dwoma powierzchniami jest pożądane, jednak nie we wszystkich.

EN

Understanding mechanisms of dynamic motion of solid surface with interfacing materials as well as tribological properties of the materials is essential to protect equipment and machinery from dilapidation. In many cases, friction between two surfaces is desired. Brakes, clutches, drives are mechanisms where friction is crucial. Interacting between tire tread and the surface of the road is another example. However, interaction between moving surfaces may result in loss of material in one or both of contacting surfaces. In majority cases friction wear is a negative phenomenon, leading to loosening motioning parts, vibrations, gliding, loss of precision, and the enlarged mechanical lumber, and yet further wear. This results in increased costs due to more frequent replacement of working parts. Wear can be minimized by use of materials with appropriate tribological properties or modifying the surface properties. Another problem in materials engineering is that depending on the type of the friction connection (e.g., sliding or rolling), the required tribological properties of interacting elements might be significantly different, and should be strictly adjusted to the application. In this article materials applied in friction drives, and methods of their characterization are reviewed.

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Problem wyznaczania zakresu parametrów wystepowania efektu tribologicznego - możliwości sterowania siłą tarcia za pomocą prądu elektrycznego

Grzywaczewski M., Fiłatowa D., Krawczyk K., Nowiński E., Witecki Z., Głogowski T.

Zeszyty Naukowe Politechniki Świętokrzyskiej. Nauki Techniczne

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2006

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Z. 1 [Terotechnologia 2006]

31-40

PL

W pracy przedstawiono przygotowanie do przeprowadzenia eksperymentów mających na celu wyznaczenie zakresów występowania nowo zauważonego efektu - możliwości sterowania siłą tarcia za pomocą prądu elektrycznego.

EN

In this work we present the preparation for the experiments, which goal is determination of the intervals of new founded effect (the possibility of the control of the friction's force by electrical current).