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A comprehensive review of polymer materials and selective laser sintering technology for 3D printing

Jabri F. E., Ouballouch A., Lasri L., Alaiji R. El

Journal of Achievements in Materials and Manufacturing Engineering

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2023

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Vol. 118, nr 1

5--17

EN

Purpose This review analyses different approaches used to study selective laser sintering (SLS) technology of polymer materials. These main approaches concern: thermal behaviour, fatigue and surface roughness. Design/methodology/approach Regarding the first behaviour, researchers extensively studied the impact of process parameters, including scan speed, laser, power and laser energy density, on the thermal behaviour of 3D printed parts. Numerical and experimental analyses are used to conduct process parameter evaluations. Findings Laser power and scan speed are the most significant parameters of the laser energy density. For the second, according to test protocols and quantitative analysis performed, the authors concluded that the combination of small and large laser energy density particles generates higher sintering and better fatigue resistance. Moreover, tensile analysis in different environments showed that testing in the water decreased the fatigue life of polymer samples. The influence of process parameters on the mechanical properties and surface roughness of 3D parts is also analysed. In addition, the investigators found that the additives increase the surface roughness of 3D printed parts. Practical implications This review shows that researchers can focus on creating a combination of these approaches to expand the use of this process for industrial part production. Originality/value All these investigations have made it possible to determine the optimal process conditions to ensure higher quality, optimal surface quality and better fatigue strength.

2

Thermal modelling of the cutting process using FEM simulation with updated thermophysical properties of tool materials

Niesłony P.

Advances in Manufacturing Science and Technology

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2008

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Vol. 32, nr 3

15-25

EN

This study compares two variants of the FEM simulation model of orthogonal cutting process of C45 carbon steel with multilayer-coated tools. In particular, new data on the thermophysical properties of the substrate and coating materials, measured by means of the advanced Laser Flash and Differential Scanning Calorimeter methods, were applied. Both simulation algorithms use the Power Law constitutive model, similar to the Johnson-Cook law but the second variant, termed Power Law' Temperature Dependent (PL-TD) algorithm, takes into account the temperature-dependent thermophysical properties of the tool. In this study, the temperature distribution, heat flux intensity and tool-chip contact length were validated based on the appropriate measurements.

PL

W artykule porównano dwa warianty symulacyjne modelu MES procesu ortogonalnego skrawania stali węglowej C45 narzędziem z powłoką wielowarstwową. Wprowadzono nowe dane cieplnofizycznych właściwości materiału substratu i powłoki określone zaawansowanymi metodami różnicowej kalorymetrii skaningowej oraz Laser-Flash. Oba zastosowane algorytmy symulacji wykorzystują wykładniczy model konstytutywny, zbliżony do modelu Johnsona-Cooka. Drugi wariant, określany Power Law-Temperature Dependent (PL-TD), uwzględnia zależne od temperatury właściwości cieplnofizyczne materiału narzędzia. W prowadzonych badaniach rozkład temperatury, intensywność strumieni ciepła oraz długość kontaktu wiór-ostrze zweryfikowano w oparciu o uzyskane wyniki pomiarowe.

3

A study on thermal behaviour of HDPE/CaCO3 nanocomposites

Zebarjad S. M., Sajjadi S. A., Tahani M., Lazzeri A.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 17, nr 1-2

173--176

EN

Purpose: In order to improve physical and mechanical properties of high density polyethylene (HDPE) addition of filler, rigid particles and even elastomer to HDPE is very common. One of the most important filler which is added to it is nano size calcium carbonate (CaCO3). To avoid agglomeration of nano size calcium carbonate addition of fatty acids such as stearic acid is very common. Design/methodology/approach: In the current study, nanocomposites with 10vol% nano size calcium carbonate were prepared. To investigate the role of stearic acid on nanocomposite behaviour, nanoparticles were coated at different stearic acid content. Thermal behaviour of high density polyethylene and its nanocomposites reinforced with both uncoated and coated calcium carbonate were investigated. For this purpose differential scanning calorimetry (DSC) test was used. Findings: The results of DSC test showed that addition of 10vol% calcium carbonate to HDPE causes a slightly rise in its melting point but stearic acid content has no significant effect on the melting temperature of HDPE nanocomposites. Research limitations/implications: Agglomeration of nanosized calcium carbonate during sample preparation was the major research limitation. Originality/value: Crystallization temperature of HDPE with addition of 10vol% calcium carbonate increases, while addition of stearic acid causes to decrease it. Both stearic acid content and 10vol% calcium carbonate have no significant effect on crystallinity index of HDPE.

4

Trwałość rurociągów poddanych oddziaływaniom mechanicznym i cieplnym

Okrajni J., Mutwil K., Cieśla M., Skibiński T.

Energetyka

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2003

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nr 7

447-455

PL

Przedstawiono niektóre zagadnienia obliczeń wytrzymałościowych rurociągów. W podsumowaniu stwierdzono, że dotychczas nie został rozwiązany problem oceny trwałości resztkowej elementów poddanych oddziaływaniom mechanicznym w ujęciu metodycznym. Nie określono również jednoznacznych kryteriów oceny stanu materiałów po wieloletnim okresie ich użytkowania.

EN

Presented are some problems of pipeline strength calculations. At a summary there is stated that there is up-to-date not solved methodologically the problem of assessment of residual durability for elements influenced by mechanical forces. There are not defined also unequivocal criteria of assessment of material condition after long time of use.