Wyniki wyszukiwania - BazTech

1

Synergistic toughening and strengthening of an epoxy resin modified by simultaneous use of two different modifiers

Białkowska Anita, Suroń Patryk, Kucharczyk Wojciech, Hanulikova Barbora, Bakar Mohamed

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2024

|

Vol. 72, nr 3

art. no. e149176

EN

The present work investigates the effect of modifying an epoxy resin using two different modifiers. The mechanical and thermal properties were evaluated as a function of modifier type and content. The structure and morphology were also analyzed and related to the measured properties. Polyurethane (PUR) was used as a liquid modifier, while Cloisite Na+ and Nanomer I.28E are solid nanoparticles. Impact strength (IS) of hybrid nanocomposites based on 3.5 wt% PUR and 2 wt% Cloisite or 3.5 wt% PUR and 1 wt% Nanomer was maximally increased by 55% and 30%, respectively, as compared to the virgin epoxy matrix, exceeding that of the two epoxy/nanoparticle binaries but not that of the epoxy/PUR binary. Furthermore, a maximum increase in IS of approximately 20% as compared to the pristine matrix was obtained with the hybrid epoxy nanocomposite containing 0.5 wt% Cloisite and 1 wt% Nanomer, including a synergistic effect, due most likely to specific interactions between the nanoparticles and the epoxy matrix. The addition of polyurethane and nanoclays increased the thermal stability of epoxy composites significantly. However, DSC results showed that the addition of flexible polyurethane chains decreased the glass transition temperatures, while the softening point and the service temperature range of epoxy nanocomposites containing nanofillers were increased. FTIR analysis confirmed the occurrence of interaction between the epoxy matrix and added modifiers. All SEM micrographs showed significant roughness of the fracture surfaces with the formation of elongated platelets, explaining the increase in mechanical properties of the epoxy matrix.

2

Możliwość wykorzystania technik mikroskopowych do oceny przebiegu procesu koagulacji

Turlej Tymoteusz

Przemysł Chemiczny

|

2023

|

T. 102, nr 11

1228--1231

PL

Przedstawiono wyniki badań dotyczących możliwości wykorzystania technik mikroskopowych do oceny przebiegu procesu koagulacji. Zaproponowano wykorzystanie zautomatyzowanego analizatora wielkości i kształtu ziaren Morphologi 4. Próbki zawiesiny rzecznej zostały poddane analizie, zarówno bez, jak i z dodatkiem koagulantu PAX 16. Przeprowadzono pomiary mikroskopowe za pomocą komórki wet-cell dla obu próbek. Ocena przebiegu procesu koagulacji została przeprowadzona przez porównanie obrazów zawiesiny bez i z dodatkiem koagulantu. Porównanie tych obrazów pozwoliło na ocenę skuteczności procesu koagulacji i zrozumienie wpływu koagulantu na morfologię cząstek. Wyniki tego badania mogą mieć zastosowanie w optymalizacji procesów koagulacji oraz w ocenie jakości wody w różnych zastosowaniach, takich jak uzdatnianie wody pitnej i oczyszczanie ścieków.

EN

Suspended river water samples were coagulated with PAX 16 and then morphol. analyzed using wet-cell microscopic measurements. The effectiveness of the coagulation process was evaluated by comparing images of the suspension without and with the addn. of coagulant. This method can be successfully used to evaluate the optimization of the coagulation process and the selection of coagulant dose.

3

Study of Si morphology in AlSi21CuNiMg cast alloy using col our and deep etching

Tillová Eva, Chalupová Mária, Kuchariková Lenka, Bonek Mirosław, Uhríčik Milan, Pastierovičová Lucia

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2023

|

Vol. 71, nr 2

art. no. e144618

EN

The effect of possible modification and refining effect of Al-Cu-P-based pre-alloy combined with Fe on the microstructure and the silicon morphology change in hypereutectic Al-Si cast alloy was studied. The samples in the as-cast state were observed by optical and scanning electron microscopy with energy-dispersive X-ray spectroscopy. The 3D morphology of both primary and eutectic silicon was observed by using colour and deep etching in detail. The results showed that the AlCu19P1.4 pre-alloy (1.07 wt.%) combined with the addition of Fe (0.02 wt.%) has a significant effect on the change of the amount, size and morphology of primary Si. This is significantly refined and changes the shape from a coarse irregular star-shaped, polyhedral, or plate-like shape to a fine polyhedral shape. The average size of the primary Si is reduced by about of 78 % from 135 μm to 28 μm and the number of primary Si particles increased from 7.4 to 237. No change in the morphology of the eutectic Si was observed; a refinement of the structure from a coarse needle/plate-like to a fine plate-like structure was seen. The depth etching method using HCl was very effective in the study of the 3D silicon morphology observed, which could be observed in detail without the presence of artefacts.

4

Mechanical properties and Mullins effect in rubber reinforced by montmorillonite

Białkowska Anita, Przybyłek Małgorzata, Sola-Wdowska Marta, Masař Milan, Bakar Mohamed

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2023

|

Vol. 71, nr 5

art. no. e147059

EN

The present work investigated the properties of rubber vulcanizates containing different nanoparticles (Cloisite 20A and Cloisite Na+) and prepared using different sonication amplitudes. The results showed that a maximum improvement in tensile strength of more than 60% over the reference sample was obtained by the nanocomposites containing 2 wt.% Cloisite 20A and 1 wt.% Cloisite Na+ and mixed with a maximum amplitude of 270 µm. The modulus at 300% elongation increased by approximately 18% and 25% with the addition of 2 wt.% Cloisite 20A and 3 wt.% Cloisite Na+, respectively. The shape retention coefficient of rubber samples was not significantly affected by the mixing amplitude, while the values of the softness measured at the highest amplitude (270 µm) were higher compared to those of mixtures homogenized with lower amplitudes. The loading-unloading and loading-reloading processes showed similar trends for all tested nanocomposites. However, they increased with increasing levels of sample stretching but were not significantly affected by filler content at a given elongation. More energy was dissipated during the loading-unloading process than during the loading-reloading. SEM micrographs of rubber samples before and after cycling loading showed rough, stratified, and elongated morphologies. XRD results showed that elastomeric chains were intercalated in the MMT nanosheets, confirming the improvement of mechanical properties. The difference between the hydrophilic pristine nanoclay (Cloisite Na+) and organomodified MMT (Cloisite 20A) was also highlighted, while the peaks of the stretched rubber samples were smaller, regardless of the rubber composition, due most probably to the decrease of interlayer spacing.

5

Flammability and morphology of Agel leaf fibre- epoxy composite modified with carbon powder for fishing boat applications

Kurniasih P., Wirawan W. A., Narto A., Pribadi O. S., Imron N. A., Rachman N. F., Pradipta A.

Archives of Materials Science and Engineering

|

2023

|

Vol. 122, nr 1

13--21

EN

Purpose: Fibre Reinforced Polymer Composites have been extensively developed to construct fishing vessels. This study reports on the successful development of the Agel Leaf Fibre (ALF)- Epoxy composite reinforced with carbon powder and fabricated using the Vacuum Infusion method. Design/methodology/approach: The composites were prepared by varying the carbon powder filler content at volumes of 0%, 10%, and 30%. The fire resistance of the composites was investigated using a burning test according to ASTM D-3014 standards. The morphology of the composites was observed through SEM analysis and analysed using ImageJ software. Findings: The research findings reveal that adding 30% carbon powder in the HCP composite reduced the burning rate by 42.624 mm/sec and the time to ignition by 17.33 seconds, indicating improved fire resistance properties. The carbon powder inhibited flame propagation and reduced the combustion rate by 0.49%. The SEM examination confirmed that the fibre porosity decreased, resulting in a denser composite with enhanced fibre-matrix adhesion. Therefore, the implementation of fire-resistant composite materials in fishing vessel construction can be realised. Research limitations/implications: The present study primarily examined the immediate effects of carbon powder additions on the morphology of the composites. However, it is crucial to consider these composites’ long-term stability and durability. Future research should investigate the ageing behaviour, considering environmental factors such as humidity, temperature, and UV radiation, to assess their impact on the morphology and flammability resistance of the composites. Additionally, it is essential to acknowledge that other factors, including fibre orientation, fibre length, and matrix properties, can significantly influence the overall performance of the composites. Practical implications: The enhanced flammability resistance of Agel Leaf Fibre-Epoxy composites with carbon powder additions holds significant benefits for fishing boat applications. In marine environments, the risk of fire incidents on fishing boats is high, making materials with good fire resistance highly desirable. Therefore, implementing fire-resistant composite materials in fishing boat construction can be realised to reduce the risk of fire incidents in high-seas fishing vessels. Originality/value: Composites with added carbon powder exhibited smaller flames, slower burning rates, and a lack of significant flame propagation. This suggests that adding carbon powder acts as an oxygen barrier and reduces the availability of fuel within the composite.

6

Wykorzystanie geometrii fraktalnej do opisu składu granulometrycznego i morfologii materiałów drobnouziarnionych

Banaś Marian, Hilger Bartłomiej

Przemysł Chemiczny

|

2022

|

T. 101, nr 11

1019--1022

PL

Geometria fraktalna jest użytecznym narzędziem wykorzystywanym w wielu dziedzinach nauki i techniki, m.in. w analizie obrazów, analizie danych finansowych, i medycynie. Stosuje się ją również do opisu morfologii fazy stałej, materiałów drobnouziarnionych, które mogą pochodzić z różnych procesów, a przez to charakteryzować się najróżniejszymi kształtami. Celem pracy jest przedstawienie sposobów opisu morfologii materiałów drobnouziarnionych za pomocą geometrii fraktalnej. W pracy zawarto informacje na temat stosowanych rozmiarów zastępczych dla cząstek fazy stałej, a także współczynników kształtów oraz metod opisywania prędkości opadania cząstek takiej fazy w płynie.

EN

Fractal geometry was used to describe the particle morphology, properties and behaviour (falling rate, permeability) in order to precisely define the particle shape in numerical form (fractal dimension). Information on the equivalent diameters of solid particles, shape factors and methods used to describe the free fall velocity of particles in a fluid were presented. The method of numerical detn. of the fractal dimension using the results of measurements obtained from a laser diffractometer was described.

7

A Morphological Characterization of High Yield Chitin from Periwinkle Shells

Odili Cletus Chiosa, Philips Gbenebor Oluwashina, Adekola Haffner Henry, Oluropo Adeosun Samson

Journal of Casting & Materials Engineering

|

2021

|

Vol. 5, no. 4

61--65

EN

Research on obtaining chitin from periwinkle shell is scarce due to the very low yield of chitin from this kind of shell. This study reports a method of processing periwinkle shells to obtain high yield, bio-medically suitable chitin. The experiment was designed using IM and 2M concentrations of HCl for demineralization and a 1M NaOH concentration for deproteinization. FTIR, SEM, XRD and DTA analytical tools were used to characterize the extracted chitin. The FTIR spectral, XRD patterns and SEM analysis, revealed the complete removal of calcium carbonate by the acid concentrations used. The particle-like form of periwinkle shell was transformed to sheet-like fiber and globular-like fiber of α-chitin by increasing the concentration of HCl from1M to 2M respectively. The crystal size increased from 11.2Å (1M HCl) to 13.4Å (2M HCl). The yield of chitin from periwinkle shell also increased from 52% to 71% using 1M and 2M HCl respectively. Thus, acid concentrations can be used to alter the structure of chitin with different mechanical properties.

8

Ocena morfologii powierzchni betonu - metody i parametry

Hoła Jerzy, Sadowski Łukasz

Inżynieria i Budownictwo

|

2021

|

R. 77, nr 7

334--337

PL

Przedstawiono klasyfikację metod badawczych i parametrów przydatnych do badania morfologii powierzchni betonu wraz z syntetycznym ich opisem i podaniem najistotniejszych ograniczeń. Zaprezentowano przykładowe wyniki badań powierzchni betonowych przygotowanych w różny sposób wraz z wartościami parametrów trójwymiarowych uzyskanymi metodą bezstykową z wykorzystaniem triangulacji laserowej.

EN

The article presents the classification of research methods and parameters useful for examining the morphology of the concrete surface, together with their synthetic description and specification of the most important limitations. Selected examples of the test results of concrete surfaces treated in various ways, together with the values of three-dimensional parameters obtained by the contactless method using laser triangulation, have been presented.

9

Effect of textured surface topography parameters on cells proliferation and tissue growth in the mechanical circulatory support application

Kurtyka Przemysław, Major Roman, Kustosz Roman, Zalewski Jerzy, Wiecek Justyna, Bartkowiak Amanda, Kaczmarek Marcin, Joszko Kamil, Grajoszek Aniela

Engineering of Biomaterials

|

2021

|

Vol. 24, no. 163

47

10

Analysis of randomly distributed particles and matrix interfaces of epoxy-based multilayered composites

Alam Shahinoor, Chowdhury Mohammad Asaduzzaman

Composites Theory and Practice

|

2021

|

R. 21, nr 3

70--86

EN

In this study, the surface morphology of composites, the effect of the particle geometry like the size and shape of the filler materials, their dispersion efficiency and interfaces are analyzed by morphological characterization. According to the tensile tests, it was found that the composites fabricated with CuO exhibit increasing trends of tensile strength in all the experiments compared to that of the composites with TiO2, which is verified by the degree of composite crystallinity determined by the strong interfacial interaction as well as the size, shape and compactness of the filler particles as observed by SEM micrograph analysis using Mountains software. Evaluation of this analysis shows similar amplitude variations in all the PSD curves of the composites and indicate a fatigue-like behavior. The stable isotropic properties in the composite samples with CuO result in a better surface finish, which was also well defined in the analysis of its surface texture and density function. Due to all these positive correlations, a significant rising trend in tensile strength (55.50, 105.53 and 20.40%) was found in every composite modified with CuO in comparison to TiO2. The highest tensile strength of the fabricated composite incorporating the CuO functional filler was found to be 105.530%. Such composites with TiO2 and CuO having a tensile strength of 117.9 and 141.95 N/mm2 respectively, may be used for the interior design of aircraft, watercraft, offices, residences, car and sports accessories and others.

11

Influence of mechanical alloying process on structural, mechanical and tribological behaviours of CNT reinforced aluminium composites – a statistical analysis

Manikandan P., Elayaperumal A., Franklin Issac R.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2021

|

Vol. 69, nr 2

art. no. e136745

EN

The mechanical and tribological properties of the Al/CNT composites could be controlled and improved by the method of its fabrication process. This research article deals with the optimization of mechanical and tribological properties of Al/CNT composites, which are fabricated using the mechanical alloying process with the different weight percentage of multi-walled CNT reinforcement. The phase change and the presence of CNT are identified using the X-Ray Diffraction (XRD) analysis. The influence of mechanical alloying process and the multi-walled CNT reinforcement on the mechanical, and tribological behaviours of the Al/CNT composites are studied. The optimal mechanical alloying process parameters and the weight percentage of multi-walled CNT reinforcement for the Al/CNT composite are identified using the Response Surface Methodology (RSM), which exhibits the better hardness, compressive strength, wear rate and Coefficient of Friction (CoF). The Al/CNT composite with 1.1 wt.% of CNT has achieved the optimal responses at the milling speed 301 rpm and milling time 492 minutes with the ball to powder weight ratio 9.7:1, which is 98% equal to the experimental result. This research also reveals that the adhesive wear is the dominant wear mechanism for the Al/CNT composite against EN31 stainless steel but the optimal Al/CNT composite with 1.1 wt.% of multi-walled CNT has experienced a mild abrasive wear.

12

Experimental Investigation of the Properties of Laminated Nonwovens Used for Packaging of Powders in Mineral Warmers

Irzmańska E., Jurczyk-Kowalska M., Bil M., Płocińska M.

Autex Research Journal

|

2021

|

Vol. 21, no. 2

163--171

EN

The study involved laminated nylon and viscose nonwovens, both perforated and non-perforated, with a view to using them for packaging of powders in mineral warmers. The nonwovens were examined in terms of morphology as well as tensile strength in dry and wet states. Thermal properties were determined by differential scanning calorimetry. Dynamic mechanical analysis was carried out in a broad range of temperatures. Surface wettability and water vapor permeability were assessed. The findings were analyzed to determine the utility of the studied materials as mineral warmer packaging materials in cold work or living environments.

13

Effect of multi-wall carbon nanotubes on the flexural performance of cement based composites

Huang Jun, Rodrigue Denis, Guo Peipei

Archives of Civil and Mechanical Engineering

|

2021

|

Vol. 21, no. 2

655--671

EN

In this work, multi-wall carbon nanotubes (MWCNT) are added (0–0.5 wt%) into a cement matrix to improve the flexural performance of the resulting nanocomposites. Under static testing, the compressive and flexural strengths were found to increase with MWCNT content with an optimum content of 0.2% and 0.1%, respectively, before decreasing because of dispersion problems (agglomeration). But it was observed that increasing the mixing time and adding silica fume improved the MWCNT dispersion. Under fatigue testing, similar trends were obtained with respect to MWCNT content as the maximum fatigue life was observed at 0.2%. A comparison between nano-silica and MWCNT reinforced concrete is also made showing that MWCNT provides better improvement at lower content. The MWCNT reinforced cement-based composite results were well fitted using linear regressions. Finally, a morphological analysis via scanning electron microscopy (SEM) was performed to explain the results based on the micro-mechanical mechanism of MWCNT reinforced composites.

14

Wpływ pochodzenia porowatego azotanu(V) amonu na jego właściwości morfologiczne

Biessikirski Andrzej

Przemysł Chemiczny

|

2020

|

T. 99, nr 10

1459--1462

PL

Przedstawiono wyniki morfologicznych i strukturalnych badań porowatego azotanu(V) amonu (AN-PP) pochodzącego od wytwórców polskich, rosyjskich, francuskich i chińskich. Badania struktury oraz morfologii przeprowadzono, stosując spektroskopię w podczerwieni (IR), dyfrakcję rentgenowską (XRD) oraz skaningową mikroskopię elektronową (SEM). W wyniku badań SEM zaobserwowano występowanie różnic morfologicznych powierzchni kryształów AN-PP, na które miało wpływ pochodzenie azotanu(V) amonu.

EN

Com. NH₄NO₃ samples of increased porosity (AN-PP) made in Poland, Russia, China and France were studied for morphol. and crystallog. by IR spectroscopy, X-ray diffraction and scanning electron microscopy. Differences in crystal structure between tested AN-PP crystals depended on NH₄NO₃ origin.

15

The effect of chain extender structure on the enzymatic degradation of carbohydrate based polyurethane elastomers

Wojturska Joanna

Polimery

|

2020

|

T. 65, nr 2

125--135

EN

Polyurethane elastomers (PUR) based on 2,2,4(2,4,4)-trimethyl-hexamethylenediisocyanate (TMDI) and polyestrodiol (Desmophen D1200) were prepared using various carbohydrates or their derivatives: monosaccharide (glucose), disaccharide (sucrose), sugar alcohol (mannitol and sorbitol). The effect of stoichiometry of ingredients and type of carbohydrates is discussed in relation to their susceptibility to enzymatic degradation catalysed by lipase from Candida antarctica (Novozym 735). The study supports the suitability of carbohydrates or sugar alcohols as important components of PUR for biomedical applications.

PL

Elastomery poliuretanowe (PUR) otrzymano z wykorzystaniem 2,2,4(2,4,4)-trimetyloheksametylenodiizocyjanianu (TMDI), poliestrodiolu (Desmophen D1200) oraz różnych węglowodanów lub ich pochodnych: monosacharydu (glukozy), disacharydu (sacharozy), alkoholi cukrowych (mannitol i sorbitol). Określono wpływ stechiometrii składników i rodzaju węglowodanów na podatność otrzymanych poliuretanów na degradację enzymatyczną katalizowaną lipazą uzyskaną z Candida antarctica (Novozym 735). Potwierdzono możliwość wykorzystania węglowodanów i alkoholi cukrowych jako istotnych składników PUR do zastosowań biomedycznych.

16

The effects of artificial-aging temperature on tensile strength, hardness, microstructure, and fault morphology in AlSiMg

Andoko, Yanuar, Puspitasari P., Ariestoni T. B.

Journal of Achievements in Materials and Manufacturing Engineering

|

2020

|

Vol. 98, nr 2

49--55

EN

Purpose: This research examined the effects of artificial-aging temperature and time on tensile strength, hardness, microstructure, and fault morphology in AlSiMg. Design/methodology/approach: This research was conducted using aluminium alloy at 120°C, 150°C, and 180°C artificial-aging temperature and 6 hours holding time. The tensile test used ASTM B211-03 standard and hardness test adapted to ALCOA 6061 standard. Findings: Tensile test results indicated the highest tenacity on aluminium alloy at a 150ºC temperature that was 47.263% strain level. In addition to the strain level, this research also obtained the highest tensile strength level at 180ºC that was 62.267 kgf/mm2 and the highest hardness value that was 110 HV. The increase in tensile strength and hardness at 180°C was caused by the increase in Mg, Si, and Al. Based on the microstructure test, the highest tenacity was obtained at 150°C temperature as the result of closed and gathered Mg2Si precipitates; while at 180°C temperature, the precipitates appeared to be more distributed, causing a rise in hardness value and tensile strength. AlSiMg tenacity also exhibited from the number of dimples compared to cleavages at 150°C temperature. Research limitations/implications: The limitation that found in this research was conducted using AlSiMg aluminium Al6061 specimen with an artificial-aging treatment at 120ºC, 150°C, and 180°C temperature for 6 hours and then compared to the raw material. AlSiMg tensile specimen was made according to ASTM E8-E8M standard. Practical implications: This research can be applied in industrial manufacture process to find tensile strength, hardness, microstructure, and fault morphology of Al6061 alloy. Originality/value: According to research result, can be understood that by conducting these experiments, Artificial-aging treatment temperature variations in AlSiMg aluminium alloy could increase hardness.

17

The effect of β-glucan on the surface morphology and roughness parameters of fish origin collagen materials

Michalska-Sionkowska Marta, Warżyńska Oliwia, Walczak Maciej, Kaczmarek Beata

Engineering of Biomaterials

|

2020

|

Vol. 23, no. 158 spec. iss.

10

18

The Effect of Electric Field on Nanofibers Preparation in Cylindrical-Electrode-Assisted Solution Blowing Spinning

Wenxing Zheng, Wenyu Zheng, Xinhou Wang

Autex Research Journal

|

2020

|

Vol. 20, no. 4

497--505

EN

Cylindrical-electrode-assisted solution blowing spinning (CSBS) is a novel nanofiber preparation method. The electric field of CSBS not only is one of the main innovations of this technology but also plays a key role in the preparation of nanofibers. In this article, the electric field of CSBS and the influences of electric field on the preparation of nanofibers were studied systematically for the first time by simulations, theoretical analyses, and experiments. This paper innovatively established the coaxial capacitor model for studying the CSBS electric field. The effects of electric field on the preparation and morphology of CSBS nanofibers were theoretically investigated by using this model. The theoretical formulas that can express the relationships between the various electric field variables were obtained. The electric field strength distribution, voltage distribution, and the relationships between the electric field parameters of CSBS were obtained by finite element simulations. The simulations’ results show that reducing the diameter of cylinder (DC) or increasing the voltage increase the electric field strength of the jet surface. Experimental results reveal that increasing voltage or reducing DC can reduce the diameter of nanofibers. The experimental and simulation results prove the correctness of the theoretical research conclusions. The theoretical and simulation conclusions of this paper lay a theoretical foundation for further study of CSBS electric field. The experimental conclusions can directly guide the controllable preparation of CSBS nanofibers.

19

Research of 316L metallic powder for use in SLM 3D printing

Hajnys J., Pagac M., Mesicek J., Petru J., Spalek F.

Advances in Materials Science

|

2020

|

Vol. 20, nr 1(63)

5--15

EN

3D metal printing is an increasingly popular production of steel parts. The most widespread and most accurate method is SLM (Selective Laser Melting), which uses metallic powder as the input material. The article is dedicated to researching the supplied powder from Renishaw. The powder is made by gas atomization and 3 phases of powder (virgin, sift and waste) that are present in the SLM process are examined. Powder morphology by SEM electron microscopy is investigated and the porosity of the powder is measured by optical method. Next, the powder grain size fraction is examined. In conclusion, there are recommendations and other directions of possible research. The main quantitative result from research is that, in general, small particles are reduced in the sift powder and the number of larger particles is increased, but the powder is still usable for further use.

20

Investigation of mechanical and physicochemical properties of clinically retrieved titanium-niobium orthodontic archwires

Stoyanova-Ivanova Angelina, Cherneva Sabina, Petrunov Vladimir, Petrova Violeta, Ilievska Ivana, Mikli Valdek, Iankov Roumen

Acta of Bioengineering and Biomechanics

|

2020

|

Vol. 22, no. 1

31--39

EN

Most of the orthodontic archwires used in the clinical practice nowadays contain nickel (Ni), however, many patients, especially kids, are allergic to Ni. One possible Ni-free alternative is the Titanium-Niobium (Ti-Nb) archwire. Unfortunately, there is not enough information about its mechanical properties in the literature, especially after clinical usage. Therefore, the aim of this work was to investigate and compare the mechanical properties, chemical composition, structure and morphology of as received and used in clinical practice Ti-Nb orthodontic archwires. Materials and methods: We investigated and compared as received and clinically retrieved after 4 and 6 weeks respectively Ti-Nb archwires with dimensions 0.43 × 0.64 mm (0.017 in. × 0.025 in.). The following methods were used: instrumented indentation testing (nanoindentation), X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. Results: The nanoindentation investigations of as received and used Ti-Nb archwires revealed a decreasing in their indentation hardness with increased periods of use in the patient’s mouth. Moreover, an increasing of the concentration of Ti in the content of the TiNb alloy was associated with an increased period of use in the oral cavity. The SEM analysis showed changes in surface morphology with increasing the period of use of the archwires. Conclusions: The results showed that there are slight changes in the mechanical and physicochemical properties of the investigated wires after their use in the patient’s mouth. That is why we do not recommend them for recycling.