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Wyszukujesz frazę "Nitinol" wg kryterium: Temat


Wyświetlanie 1-10 z 10
Tytuł:
The Effects of Niobium on the Bioactivity of Ni-Ti-Al-Nb Shape Memory Alloys
Autorzy:
Teixeira, Ricardo Luiz Perez
de Lacerda, José Carlos
Conceição, Isabella Carolina
da Silva, Sidney Nicodemos
Siqueira, Guilherme O.
Moura, Francisco
Powiązania:
https://bibliotekanauki.pl/articles/2049692.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nitinol
niobium
aluminum
bioactivity
cytotoxicity
Opis:
This work aims to analyze the effects of niobium on the bioactivity of a titanium, nickel, aluminum, and niobium alloy obtained by the Plasma Skull Push Pull process (PSPP). Titanium alloys, such as NiTinol (NiTi), are metallic biomaterials that have wide application in health and surgical prostheses. In this work the microstructural and bioactivity characteristics of the alloys are evaluated. The addition of aluminum improves alloy ductility and reduces its cost. The addition of niobium favors the hydroxyapatite nucleation. Therefore, the addition of the combination of the two elements contributes to lower cost and better alloy bioactivity.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 2; 437-442
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative analysis of machinability of nitinol alloy using weighted radar diagram
Autorzy:
Kowalczyk, M.
Niżankowski, C.
Powiązania:
https://bibliotekanauki.pl/articles/407070.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
machinability
nitinol
TiNi
weighted radar diagram
Opis:
The paper presents an attempt to analyze comparative machinability of two different varieties of nitinol alloy type, or compare the susceptibility of these materials to change the volume, shape and dimension of adopted machining conditions. The machinability of the material can not be fully determined numerically by only one independent factor. Therefore multivariate analysis technique of weighted diagram radar was developed by authors. This technique allowed for the comprehensive identification machinability analyzed varieties of nitinol alloy exclusively on the basis of the specified in literature directional material properties and general recommendations tool manufacturers on the cutting conditions. In the paper the full usefulness of this technique to demonstrate the differences in machinability of different varieties of the same species alloy, without the need for lengthy and cost-intensive experimental trials was presented.
Źródło:
Management and Production Engineering Review; 2017, 8, 4; 74-81
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chemical etching of Nitinol stents
Autorzy:
Katona, B.
Bognar, E.
Berta, B.
Nagy, P.
Hirschberg, K.
Powiązania:
https://bibliotekanauki.pl/articles/307073.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
stent
nitinol
chemical etching
metallic surface area
Opis:
At present the main cause of death originates from cardiovascular diseases. Primarily the most frequent cause is vessel closing thus resulting in tissue damage. The stent can help to avoid this. It expands the narrowed vessel section and allows free blood flow. The good surface quality of stents is important. It also must have adequate mechanical characteristics or else it can be damaged which can easily lead to the fracture of the implant. Thus, we have to consider the importance of the surface treatment of these implants. In our experiments the appropriate design was cut from a 1.041 mm inner diameter and 0.100 mm wall thickness nitinol tube by using Nd:YAG laser device. Then, the stent was subjected to chemical etching. By doing so, the burr created during the laser cutting process can be removed and the surface quality refined. In our research, we changed the time of chemical etching and monitored the effects of this parameter. The differently etched stents were subjected to microscopic analysis, mass measurement and in vivo environment tests. The etching times that gave suitable surface and mechanical features were identified.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 4; 3-8
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Processing of Porous NiTi Preforms for NiTi/Mg Composites
Autorzy:
Kucharczyk, A.
Naplocha, K.
Tomanik, M.
Powiązania:
https://bibliotekanauki.pl/articles/352563.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
metal matrix composite
magnesium
nitinol
SHS
squeeze casting
Opis:
NiTi alloys are successfully used in engineering and medical applications because of their properties, such as shape memory effect, superelasticity or mechanical strength. A composite with Mg matrix, due to its vibration damping properties, can be characterized by low weight and good vibration damping properties. In this study, a combination of two techniques was used for successful fabrication of Mg composite reinforced by NiTi alloy preform. The porous preforms synthesized by Self-propagating Hightemperature Synthesis (SHS) from elemental powders were subsequently infiltrated with Mg by squeeze casting. The effects were examined with scanning electron microscope with EDS detector, X-ray diffraction and microindentation. The inspection has shown well-connected matrix and reinforcement; no reaction at the interface and open porosities fully infiltrated by liquid Mg. Moreover, analysis of samples’ fracture has exhibited that crack propagates inside the Mg matrix and there is no detachment of reinforcement.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 2; 747-752
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the Nitinol properties improvement after electrochemical treatments
Autorzy:
Hryniewicz, Tadeusz
Rokicki, Ryszard
Powiązania:
https://bibliotekanauki.pl/articles/1178042.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Nitinol
SMA
electropolishing (EP)
fatigue resistance
inclusions
magnetoelectropolishing (MEP)
Opis:
Shape Memory Alloys (SMAs) are a group of intermetallic compounds, which can undergo deformation at one temperature, and then recover their original undeformed shape upon heating above their transformation temperature. Superelasticity occurs just above the alloy’s transformation temperature in a very narrow range. In this case no heating is necessary to cause the deformed shape to recover upon load relieve to its original undeformed shape. It has to be emphasized that nitinol exhibits enormous elasticity when compared with other medical metal alloys. In recent years, the use of nitinol (NiTi), almost equiatomic binary (50:50 ratio) intermetallic compound of nickel and titanium, has been steadily growing, particularly in medical and dental devices markets. However, broader and further application of nitinol has been slowed down by leaking nickel and unavoidable inclusions during producing in this compound. This work is to present some electrochemical treatment methods in view of reducing of both these phenomena. It appears that changing electrical conditions of electropolishing (EP) above the plateau region (EP+) may improve the quality of surface obtained on NiTi of over 60% in comparison with as-received (AR) nitinol part. What’s more, introducing a magnetic field into the electrolysis system results in numerous positive features of nitinol surface and increase of mechanical properties. Thus the magnetoelectropolishing (MEP) process appears to increase higher the fatigue resistance of the treated NiTi part. The experiments carried out on chirurgical needles show an unusual triple (and higher) growth in resistance to bending until fracture. Further increase in fatigue resistance is usually limited by different size inclusions appearing on the nitinol part surface under magnetoelectropolishing (MEP).
Źródło:
World Scientific News; 2018, 95; 52-63
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chwytak napędzany materiałem z pamięcią kształtu (Ni-Ti)
The gripper actuated by shape memory material (Ni-Ti)
Autorzy:
Lubiński, M.
Powiązania:
https://bibliotekanauki.pl/articles/154861.pdf
Data publikacji:
2009
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
nitinol
chwytak
pamięć kształtu
gripper
shape memory
SMA
Opis:
Pomimo licznych niespotykanych cech i zalet materiałów z pamięcią kształtu, wykorzystanie ich w profesjonalnych rozwiązaniach wiąże się z licznymi utrudnieniami. W artykule przedstawiono prototypową konstrukcję uniwersalnego chwytaka napędzanego przewodami Nitinolu. Zaprezentowany został projekt chwytaka wraz z analizą kinematyki i sił. Porównano teoretyczne parametry pracy z rzeczywistymi, pochodzącymi z przeprowadzonych badań. Ukazano wynikłe problemy, których nie przewidziano na etapie projektu. Przeprowadzono symulacje różnych sposobów zasilania.
Shape memory materials because of their unique characteristics are used in more and more applications. The use of shape memory materials in professional solutions gives a lot of advantages but it is connected also with many difficulties. The paper presents all-purpose prototype gripper actuated by Nitinol wires. The gripper project is shown with kinematic and force analysis. In this paper You can find equations for position jaws the gripper, and formulas for rotations platforms. The gripper scheme with decomposition vectors is shown in Figure 2. In the Figure 1 is shown the gripper 3D model created in dedicated software, Figure 3 presents real gripper with manipulation object. Theoretical working parameters were compared with real ones found from constructed test mechanism. The real shortening Nitinol wire was only 2,4%. It is 40% less then given in information sheets from manufacturer. The problems shown in the article weren't predicted on the design stage. Different types of power supply were simulated.
Źródło:
Pomiary Automatyka Kontrola; 2009, R. 55, nr 9, 9; 737-739
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Highly improved Nitinol biomaterial devices by magnetoelectropolishing (MEP)
Autorzy:
Hryniewicz, Tadeusz
Rokicki, Ryszard
Powiązania:
https://bibliotekanauki.pl/articles/1166214.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Biocompatibility
Fatigue resistance
Nitinol biomaterial
Surface roughness
XPS
magnetoelectropolishing
Opis:
In recent years, the use of Nitinol as a metallic biomaterial being compound of nickel and titanium, has been steadily growing, particularly in medical and dental devices markets. However, further application of Nitinol has been slowed down due to leaching nickel and unavoidable inclusions appearing on the surface during manufacture of this intermetallic compound. Electropolishing of Nitinol biomaterial samples as-received (AR) was carried out under different conditions: (a) on the plateau level (EP), (b) above the plateau (EP+), and (c) in the magnetic field (MEP). This work is to present magnetoelectropolishing (MEP) as an electrochemical processing method able to significantly improve the Nitinol biomaterial properties. Following our previous SEM/EDS studies, and corrosion resistance improvement of Nitinol, in this work XPS and XRD study methods were used. First of all, as indicated by XPS study results concerning biocompatibility, it was proved that MEP leaves Nitinol surface enriched in oxygen and with nickel reduced to zero. Thus the titanium oxides, generally TiO2, are formed on Nitinol surface. It appears that by introducing a magnetic field into the electrolysis system, another effect relying on a considerable increase of Nitinol mechanical properties is obtained. The experiments carried out on surgical needles show an unusual multiple growth in resistance to bending until fracture. Further increase in fatigue resistance is usually limited by different size of inclusions which happen to appear on the Nitinol part surface. Moreover, in this work also a simple method is proposed to reject the Nitinol parts, with the inclusions detected on the biomaterial surface, before their application.
Źródło:
World Scientific News; 2018, 106; 175-193
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the wear inspection and endurance recovery of Nitinol endodontic files
Kontrola zużycia i poprawa jakości nitinolowych wierteł endodontycznych
Autorzy:
Hryniewicz, T.
Rokosz, K.
Powiązania:
https://bibliotekanauki.pl/articles/156461.pdf
Data publikacji:
2009
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
wiertła endodontyczne
nitinol
magnetoelektropolerowanie
SEM
interferometria
Endodontic rotary files
magnetoelectropolishing
interferometry
Opis:
The aim of this study was to reveal the effects of operation of endodontic rotary files during a normal use and the possibilities for their endurance recovery. The effect of magnetoelectropolishing on the basic surface, and mechanical properties of Nitinol endodontic rotary files has been also studied. The investigation covered surface interferometry measurements, and SEM studies referred to two groups of endodontic instruments: ready-to-use and/or as-received (AR) tools, and magnetoelectropolished (MEP) instruments, meaning treated by electropolishing in a magnetic field. Overall, magnetoelectropolished (MEP) instruments indicated significantly better surface characteristics than those as-received (AR). Our earlier studies have revealed several better and improved surface characteristics of Nitinol samples treated with MEP in comparison with those electropolished under standard EP conditions and as-received (AR) ones. Specifically it has been found that magnetoelectropolishing MEP process may improve the surface, corrosion, and fatigue characteristics of Nitinol samples. When viewing the as-received (AR) instruments with SEM, and measuring the instrument treated surface by interferometry, the evidences of milling grooves, cracks, pits, and metal rollover were observed, contrary to the endodontic file surface after magnetoelectropolishing (MEP). The MEP process has improved most of surface characteristics, having beneficial effects in prolonging the fatigue life of samples. The benefits of MEP process are likely to be caused by a reduction in surface irregularities and essential changes in surface film properties.
W pracy ukazano warunki pracy i sposoby zużycia nitinolowych narzędzi endodontycznych oraz możliwości poprawy ich trwałości / jakości. Badania obejmowały SEM i interferometrię narzędzi uszkodzonych w procesie powiększania kanału zębnego, oraz narzędzi po magnetoelektropolerowaniu (MEP). Zużycie narzędzi następuje głównie w wyniku zmęczenia materiału i zależy od ukształtowania kanału zębnego. Wstępne badania wykazują, że proces MEP, poprzez zmiany w warstwie wierzchniej, poprawia mechaniczne właściwości Nitinolu.
Źródło:
Pomiary Automatyka Kontrola; 2009, R. 55, nr 4, 4; 247-250
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modification of Nitinol Biomaterial for Medical Applications
Autorzy:
Hryniewicz, Tadeusz
Rokicki, Ryszard
Powiązania:
https://bibliotekanauki.pl/articles/1177981.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Nitinol biomaterial
electropolishing
fatigue resistance
magnetoelectropolishing (MEP)
modification methods
sterilization
Opis:
In the paper, a review of modification methods which have been applied to Nitinol intermetallic compound used as biomaterial for medical applications, is carried out. A variety of methods used for Nitinol improvement, beginning from its manufacture, covers mechanical treatment, heat treatment, chemical processing including water boiling, electropolishing, plasma ion implantation, coating to improve the corrosion resistance, minimize nickel leaching, improve osseointegration, and/or vascular compatibility, sterilization and disinfection. Nitinol alloying by addition of a third element to replace Ti or Ni has an enormous effect on phase transformation, corrosion resistance and biocompatibility of the newly created ternary Nitinol alloy. Unfortunately, the ternary nitinol alloys – apart from NiTiCu in actuators and NiTiCr in wires used as a pulling-pushing tool in minimally invasive spine operation – have not found a widespread industrial application yet. One of the most effective surface finishing operations used for metallic biomaterials, with a special attention directed to Nitinol, appears to be magnetoelectropolishing (MEP). A uniform magnetic field used in MEP process can be generated by permanent magnets or by electromagnets. MEP leads to refinement of surface chemical composition impossible to achieve by standard electropolishing. During MEP of alloys and intermetallic compounds, ferromagnetic elements, such as Fe (from stainless steels) or Ni, are primarily removed from the surface so that the passive film on Nitinol is totally composed of titanium oxide. One more unique feature of metal samples after MEP is their de-hydrogenation noticed both in stainless steels, niobium, titanium and Nitinol. In fact, the fatigue resistance of Nitinol after MEP referred to as-received, dependent on the refinement and displacement of inclusions, increases from three to seven times.
Źródło:
World Scientific News; 2018, 96; 35-58
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of mechanical strength and corrosion resistance at variable pH of orthodontic wires
Autorzy:
Augustyn-Nadzieja, Joanna
Szczotok, Agnieszka
Powiązania:
https://bibliotekanauki.pl/articles/1844971.pdf
Data publikacji:
2020
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
tensile test
orthodontic wires
austenitic steel
nitinol (NiTi)
Tiβ
corrosion resistance
Opis:
Orthodontic wires are components of fixed appliances used to perform the necessary tooth movements in the course of the orthodontic treatment. A variety of materials e.g. metals, alloys, polymers and composites are used to produce orthodontic wires. This study examined the mechanical strength and cracks resistance of three different types of wires, i.e. made of: austenitic steel grade AISI 303, NiTi alloy and Tiβ alloy. Corrosion processes are regarded to have a harmful effect on the properties of orthodontic wires, such as their strength, biocompatibility and aesthetic appearance. In this study, we investigated the corrosive behaviour of the wires in the artificial saliva solutions with varied pH simulating the natural oral cavity environment. It was demonstrated that the orthodontic rectangular wires made of austenitic steel grade AISI 303 exhibited the highest tensile strength. The NiTi alloy wires exhibited the best plastic properties of all the examined samples. In the case of electrochemical tests (changes in corrosion potential over a period of 24 h), the wire made of austenitic steel and the NiTi alloy wire reached a stable level of the stationary potential in the acidic environment. For the wires made of Tiβ, the highest stationary potential was observed in the alkaline environment. Additionally, the Tiβ alloy wire revealed the broadest passivation area in the specified potential scope.
Źródło:
Engineering of Biomaterials; 2020, 23, 157; 2-9
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-10 z 10

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