Wyniki wyszukiwania - BazTech

1

Nanoporous surface treatment of aluminium by anodisation in oxalic acid

Dass G., Kushwaha M. K.

Journal of Achievements in Materials and Manufacturing Engineering

|

2019

|

Vol. 93, nr 1-2

20--25

EN

Purpose: Well-ordered nanoporous anodic surface on aluminium substrate was obtained by anodisation method in 0.3 M of oxalic acid as an electrolyte. The objective of this perusal is to describe a system for the magnifying diameter of pores and resistance of demolition of the oxide layer at various voltages. The effect of voltage and time of anodisation process in which obtaining the required structure in AAO film. Design/methodology/approach: The experiments have been performed on a setup for anodisation considering variables parameters. In this study, AAO Templates were prepared in oxalic acid of 0.3 M concentration under the potential range of anodisation 30-40 V at relatively temperatures range from 20-30°C of an electrolyte. Anodic voltage, current density and temperature of electrolyte were adopted as electrical parameters during anodisation. Before anodisation starts two crucial pre-treatment i.e. annealing and electropolishing are finished. Findings: The diameter of pores and pitch of pores are well-proportional to anodisation voltage and process time. The pore diameters were 85 nm, 138 nm, 184 nm, 248 nm with having 9, 16, 27, 37 porosity % respectively. The thickness of AAO film in all cases has been found to be maximum or constant after one hour in second step anodisation. The anodisation parameters like voltage, the time duration of the anodisation process and temperature are very essential features which influencing the fabrication of an AAO film. Research limitations/implications: The anodisation process is very easy to perform but very complex to understand as there are many parameters which may affect it. Practical implications: After that, the second step anodisation for the next half hour, there will be no change in the thickness of AAO film but after that dissolution rate starts over the formation rate and finally thickness will be decreasing. Originality/value: Therein is numerous macropores in the membrane with the size of pores variation from 163 to 248 nm. The diameter of pores, thickness, and pore density of AAO film was determined through Scanning Electron Microscopy (SEM), which exhibited that homogeneous honeycomb-like structure has appeared on the entire surface where anodisation performed precisely.

2

Nanoporowata struktura tlenku aluminium w anodyzacji jedno i dwuetapowej

Juchim S.

Przegląd Elektrotechniczny

|

2013

|

R. 89, nr 7

155--157

PL

W artykule porównano parametry fizyczne nanoporowatej matrycy z tlenku aluminium wykonanej w technice dwuetapowej, z parametrami podobnej matrycy uzyskanej w uproszczonej technologii jednoetapowej. Analizie poddano przebieg zmian parametrów elektrycznych obwodu anodyzacji w obu technologiach a także przeprowadzono obrazowanie powierzchni za pomocą mikroskopu typu FE-SEM.

EN

In the paper is presented a comparison of physical parameters of alumina template made by use of one (simplified) and two-step anodisation. The analyze was taken on the electrical parameters of anodisation circuits of both of the technologies and the visualization of surface was carried on by means of FE-SEM microscope.

3

HPDL Remelting of Anodised Al-Si-Cu Cast Alloys Surfaces

Labisz K., Tański T., Janicki D.

Archives of Foundry Engineering

|

2012

|

Vol. 12, iss. 2s

45--48

EN

The results of the investigations of the laser remelting of the AlSi9Cu4 cast aluminium alloy with the anodised and non-anodised surface layer and hardness changes have been presented in this paper. The surface layer of the tested aluminium samples was remelted with the laser of a continuous work. The power density was from 8,17•103 W/cm2 to 1,63•104 W/cm2. The metallographic tests were conducted in form of light microscope investigations of the received surface layer. The main goal of the investigation was to find the relation between the laser beam power and its power density falling on a material, evaluating the shape and geometry of the remelted layers and their hardness. As the substrate material two types of surfaces of the casted AlSi9Cu4 alloy were applied – the non–treated as cast surface as well the anodized surface. As a device for this type of surface laser treatment the High Power Diode Laser was applied with a maximum power of 2.2 kW and the dimensions of the laser beam focus of 1.8 x 6.8 mm. By mind of such treatment it is also possible to increase hardness as well eliminate porosity and develop metallurgical bonding at the coating-substrate interface. Suitable operating conditions for HPDL laser treatment were finally determined, ranging from 1.0 to 2.0 kW. Under such conditions, taking into account the absorption value, the effects of laser remelting on the surface shape and roughness were studied. The results show that surface roughness is reduced with increasing laser power by the remelting process only for the non-anodised samples, and high porosity can be found in the with high power remelted areas. The laser influence increases with the heat input of the laser processing as well with the anodisation of the surface, because of the absorption enhancement ensured through the obtained alumina layer.

4

Impedancyjna charakterystyka anodowanego tytanu w badaniach in vitro

Głazowska I., Krasicka-Cydzik E.

Inżynieria Biomateriałów

|

2005

|

R. 8, nr 47-53

127--130

PL

W pracy przedstawiono badania impedancyjne tytanu po anodowaniu w roztworze kwasu fosforowego. Testy impedancyjne prowadzono w symulowanym roztworze soli fizjologicznej SBF w temperaturze 298K. Próbki poddano anodowaniu galwanostatycznemu w 0,5M i 2M roztworze H3PO4, przy gęstości prądowej 0,5 Am2 w czasie 1000 s. Analizę impedancyjną (EIS) prowadzono po 2h oraz po 2, 4, 6 i 8 dniach przechowywania próbek w roztworze SBF. W pomiarach impedancyjnych stosowano impuls zmienny 10 mV o częstotliwości od 10(5) Hz do 0,18 Hz, nakładany na potencjał korozyjny Ekor (NEK). Badania wykazały zmiany wielkości impedancji warstw powierzchniowych podczas zanurzenia w SBF w ciągu 8 dni i ujawniły wpływ stężenia kwasu na pojemność i oporność tych warstw.

EN

The impedance behaviour of anodized Ti was studied in the simulated physiological solution SBF at temperature 298K. The specimens were anodised in 0.5M and 2M phosphoric acid solutions, at 0.5 Am2 current density for 1000s and then examined electrochemical impedance spectroscopy (EIS) in SBF solution, with ac impulse of 10 mV, in the frequency range between 10(5) Hz and 0.18 Hz, superimposed to corrosion potential Ecorr (SCE). Changes of the impedance of surface layers during 8 days immersion SBF showed the effect of the electrolyte concentration on the capacity and the resistance of these layers.

5

Zmiany impedancji warstw anodowych na implantowych stopach tytanu po zanurzeniu w roztworze Ringera

Krasicka-Cydzik E., Haładyn J.

Inżynieria Biomateriałów

|

2002

|

R. 5, nr 23-25

43-46

PL

W pracy przedstawiono zmiany zachodzące na powierzchni anodowanych próbek tytanu i jego implantowych stopów Ti6Al4V ELI oraz Ti6Al7Nb, zanurzonych w roztworze Ringera. Próbki badanych materiałów polerowano na połysk lustrzany, anodowano galwanostatycznie w roztworach H3PO4 o stężeniach od 0,5 do 3 M, stosując gęstość prądu 0,5 Am-2 w czasie 600 s, a następnie zanurzano na 6 tygodni do roztworu Ringera o temperaturze 298 K. Na podstawie badań impedancyjnych prowadzonych w trakcie zanurzenia stwierdzono zróżnicowany przebieg zmian pojemności elektrycznej warstw powierzchniowych, uzależniony zarówno od rodzaju anodowanego materiału, jak również od stężenia kwasu fosforowego. Analiza mikroskopowa (SEM i EDS) powierzchni analizowanych próbek po 6 tygodniach zanurzenia w roztworze Ringera wykazała obecność fosforanów wapnia, sodu i magnezu w warstwie pokrywającej powierzchnię badanych materiałów. Po anodowaniu w 0,5 M H3PO4 przeważały wydzielenia fosforanów wapnia, natomiast w warstwie pokrywającej materiały anodowane w 2 M H3PO4 dominowały fosforany magnezu i sodu, a w przypadku stopu Ti6Al4V ELI, także fosforanu glinu.

EN

The changes in impedance of titanium and its implant alloys Ti6Al4V ELI and Ti6Al7Nb mechanically polished to mirror finish and anodised, were registered during immersion up to 6 weeks at 298 K in Ringer's solution. Prior to immersion samples were anodized in phosphoric acid solutions at different concentrations (0,5-3 M), Changes in capacitance of surface layers, dependent on both the concentration of phosphoric acid and the type of material, were observed. SEM and EDS investigations revealed the presence of calcium phosphates, as well as magnesium and sodium phosphates on the surface of the immersed samples. However, calcium phosphate predominated in the layer formed in 0,5 M H3PO4, whereas magnesium and sodium phosphates, as well aluminum phosphate were present mainly in surface layer formed in 2 M H3PO4.