Alkali-Heat Treatment of Ti-6Al-4V to Hydroxyapatite Coating Using Electrophoretic Method

2020 ◽  
Vol 846 ◽  
pp. 175-180 ◽  
Author(s):  
Sugeng Supriadi ◽  
Sri Lubriandini Putri ◽  
Rizkijanuar Ramadhan ◽  
Bambang Suharno

The deposition of hydroxyapatite has been applied to enhance the bioactivity of Ti-6Al-4V as implant materials. However, the hydroxyapatite has poor adhesion strength to a substrate which can lead to coating delamination. In this study, we combine the alkali-heat treatment of Ti-6Al-4V and the electrophoretic coating process of the hydroxyapatite to obtain the strong mechanical interlocking. The Ti-6Al-4V implants were etched in Kroll solution before the alkali-treatment was performed using 5M and 10M NaOH at 24, 48 and 72 hours and thermally stabilized at 600°C and 800°C for 1 hour using a stepwise heating rate of 5°C per min. The electrophoretic deposition process conducted at a constant cell voltage of 20 V for 10 min at room temperature and then sintered in a vacuum furnace at 800°C. The result shows that the feather-like structure on Ti-6Al-4V surface was created by incorporating sodium ions onto the Ti-6Al-4V surface during alkali-treatment using NaOH 5M for 48h and stabilized using heat treatment at 600°C where the hydroxyapatite filled the interspaces to become integrated with the feather-like structure so that the osseointegration can occur as the bioactivity increased.

Author(s):  
S.K. Streiffer ◽  
C.B. Eom ◽  
J.C. Bravman ◽  
T.H. Geballet

The study of very thin (<15 nm) YBa2Cu3O7−δ (YBCO) films is necessary both for investigating the nucleation and growth of films of this material and for achieving a better understanding of multilayer structures incorporating such thin YBCO regions. We have used transmission electron microscopy to examine ultra-thin films grown on MgO substrates by single-target, off-axis magnetron sputtering; details of the deposition process have been reported elsewhere. Briefly, polished MgO substrates were attached to a block placed at 90° to the sputtering target and heated to 650 °C. The sputtering was performed in 10 mtorr oxygen and 40 mtorr argon with an rf power of 125 watts. After deposition, the chamber was vented to 500 torr oxygen and allowed to cool to room temperature. Because of YBCO’s susceptibility to environmental degradation and oxygen loss, the technique of Xi, et al. was followed and a protective overlayer of amorphous YBCO was deposited on the just-grown films.


2013 ◽  
Vol 807-809 ◽  
pp. 2110-2114
Author(s):  
Shu Quan Wan ◽  
De Jun Lan ◽  
Hong Bo Han ◽  
Cai Long Zhou

The phases of Panzhihua vanadic titanomagnetite ore were studied by using XRF and XRD. XRF results show that the original ore mainly contain the elements, Fe, Ti, Si, Ca, Al, S, Mg, P, Mn, V and etc. XRD results show that the main substances in original ore were Fe3O4 and FeTiO3, and the minor phases cannot be clearly studied by XRD. After heat treatment for 10h at 573K in atmospheric ambient, the phases of the ore have been slightly changed. And after heat treatment for 10h at 1073K in atmospheric ambient, then cooled for 48h to room temperature, the main phases of the ore have almost been changed to Fe2O3 and Fe2TiO5.


Author(s):  
Jinglong Liang ◽  
Jing Wang ◽  
Hui Li ◽  
Chenxiao Li ◽  
Hongyan Yan ◽  
...  

AbstractMassive deployment of lithium-ion battery inevitably causes a large amount of solid waste. To be sustainably implemented, technologies capable of reducing environmental impacts and recovering resources from spent lithium-ion battery have been an urgent task. The electrochemical reduction of LiNiO2 to metallic nickel has been reported, which is a typical cathode material of lithium-ion battery. In this paper, the electrochemical reduction behavior of LiNiO2 is studied at 750 °C in the eutectic NaCl-CaCl2 molten salt, and the constant cell voltage electrolysis of LiNiO2 is carried out. The results show that Ni(III) is reduced to metallic nickel by a two-step process, Ni(III) → Ni(II) → Ni, which is quasi-reversible controlled by diffusion and electron transfer. After electrolysis for 6 h at 1.4 V, the surface of LiNiO2 cathode is reduced to metallic nickel, with NiO and a small amount of Li0.4Ni1.6O2 detected inside the partially reduced cathode. After prolonging the electrolysis time to 12 h, LiNiO2 is fully electroreduced to metallic nickel, achieving a high current efficiency of 98.60%. The present work highlights that molten salt electrolysis could be an effective protocol for reclamation of spent lithium-ion battery.


2018 ◽  
Vol 284 ◽  
pp. 615-620 ◽  
Author(s):  
R.M. Baitimerov ◽  
P.A. Lykov ◽  
L.V. Radionova

TiAl6V4 titanium base alloy is widely used in aerospace and medical industries. Specimens for tensile tests from TiAl6V4 with porosity less than 0.5% was fabricated by selective laser melting (SLM). Specimens were treated using two heat treatment procedures, third batch of specimens was tested in as-fabricated statement after machining. Tensile tests were carried out at room temperature. Microstructure and mechanical properties of SLM fabricated TiAl6V4 after different heat treatments were investigated.


2015 ◽  
Vol 1784 ◽  
Author(s):  
Mingu Kim ◽  
Gwanghyo Choi ◽  
Daeheung Yoo ◽  
Kwangmin Lee

ABSTRACTThe band gap energy of the TiO2 photocatalytic is high at 3.2 eV. Ultraviolet (UV) light irradiation (<388nm) is required for the photocatalytic application. The lowering the band gap energy of TiO2 and enlarging light absorbing area are effective ways to enhance the efficiency of photocatalytic activity. Furthermore, the morphology and crystal structure of nanosized TiO2 considerably influences its photocatalytic behavior.In this study, sodium titanate nanorods were formed using an alkali-treatment and were heat treated at different temperatures. The photoelectrochemical properties of sodium titanate nanorods was measured as a function of heat treatment temperature. The nanorods were prepared on the surface of Ti disk with a diameter of 15mm and a thickness of 3mm. Ti disk was immersed in 5 M NaOH aqueous solution at a temperature of 60 °C for 24 h. Morphology of sodium titanate nanorods was observed using FE-SEM. Crystal structure of sodium titanate nanorods was analyzed using X-ray diffractometer. Photoluminescence (PL) and electrochemical impedance spectroscopy (EIS) was used to evaluate photoelectrochemical properties of sodium titanate nanorods. The thin amorphous sodium titanate layer was formed during alkali-treatment. The sodium titanate layer was changed to nanorods after heat treatment at a temperature of 700 °C. The thickness and length of sodium titanate nanorods obtained at 700 °C were around 100 nm and 1μm, respectively. The crystal structure of sodium titanate was identified with Na2Ti6O13. Above 900 °C, the morphology of nanorods changed to agglomerated shape and the thickness of nanorods increased to 1 μm. The lowest value of PL was obtained at a temperature of 700 °C, while nonalkali treated specimen showed the highest value of PL. EIS revealed that polarization resistance at interface between sodium titanate nanorods and electrolyte was increased with increasing heat treatment temperature.


2018 ◽  
Vol 11 (1) ◽  
pp. 6
Author(s):  
Cokorda putri Kusuma kencanawati ◽  
I Ketut Gede Sugita ◽  
NPG Suardana ◽  
I Wayan Budiasa Suyasa

Makalah ini menganalisis pengaruh perlakukan alkali dan tanpa perlakukan alkali terhadap karakateristik fisik, morfologi dan sifat mekanik serat kulit buah pinang (areca Catechu L.). Selama ini pemanfaatan limbah pertanian belum dilakukan secara maksimal, sehingga dapat menimbulkan pencemaran terhadap lingkungan. Serat kulit buah pinang (Areca Husk Fiber/AHF) selama ini hanya dipergunakan sebagai bahan bakar biomassa dan media tanam sedangkan untuk pemanfaatan lain belum ada sama sekali. AHF diberi perlakukan NaOH 2,5%, 5%, 7,5% dan 10% dengan waktu perendaman 2 jam pada temperatur kamar, untuk mengetahui karakteristik fisik AHF maka dilakukan pengukuran panjang dan diameter serat, pengujian densitas, pengujian kadar air dan moisture sedangkan untuk mengetahui karakteristik mekanik dilakukan pengujian tarik serat tunggal sesuai dengan ASTM D 3379. Dari penelitian ini diketahui bahwa diameter AHF mengalami pengurangan diameter akibat perlakukan alkali, hal ini terkait dengan hilangnya kandungan lignin, pektin dan wax. Densitas AHF menurun dengan meningkatan prosentase NaOH bila dibandingkan dengan AHF tanpa perlakukan NaOH. Kekuatan tarik bervariasi dengan adanya perlakuan alkali.  Kekuatan tarik AHF tertinggi pada serat yang mengalami perlakukan NaOH 5% yaitu sebesar 165 Mpa dan kekuatan tarik terendah pada AHF dengan perlakuan Alkali 10% yaitu sebesar 137 MPa . This paper analyzes the effect of alkali and non-alkali treatments on the physical characteristics, morphology and mechanical properties of betel nut huks fiber (areca Catechu L.). the used of agricultural waste has not been done optimally, causing environmental pollution. Areca Husk Fiber (AHF) only used as biomass fuel and planting medium, while for the other uses it has not existed. AHF was given 2.5%, 5%, 7.5% and 10% NaOH treatment with 2 hours immersion at room temperature, to known the physical characteristics of AHF then measured the length and diameter of fiber, density test, water content and moisture test. Mechanical characteristics of single fiber tensile testing in accordance with ASTM D 3379. From this study that known the diameter of AHF has a reduction in diameter due to alkaline treatment, this is related to loss of lignin, pectin and wax content. The density of AHF decreases with the percentage increase of NaOH when compared with AHF without the treatment of NaOH. Tensile strength varies with alkaline treatment. The highest AHF tensile strength in treated fibers was 5% NaOH of 165 Mpa and lowest tensile strength in AHF with 10% Alkali treatment of 137 MPa.


2006 ◽  
Vol 114 ◽  
pp. 91-96 ◽  
Author(s):  
Maxim Yu. Murashkin ◽  
M.V. Markushev ◽  
Julia Ivanisenko ◽  
Ruslan Valiev

The effects of equal channel angular pressing (ECAP), further heat treatment and rolling on the structure and room temperature mechanical properties of the commercial aluminum alloys 6061 (Al-0.9Mg-0.7Si) and 1560 (Al-6.5Mg-0.6Mn) were investigated. It has been shown that the strength of the alloys after ECAP is higher than that achieved after conventional processing. Prior ECAP solution treatment and post-ECAP ageing can additionally increase the strength of the 6061 alloy. Under optimal ageing conditions a yield strength (YS) of 434 MPa and am ultimate tensile strength (UTS) of 470 MPa were obtained for the alloy. Additional cold rolling leads to a YS and UTS of 475 and 500 MPa with 8% elongation. It was found that the post-ECAP isothermal rolling of the 1560 alloy resulted in the formation of a nano-fibred structure and a tensile strength (YS = 540 MPa and UTS = 635 MPa) that has never previously been observed in commercial non-heat treatable alloys.


2009 ◽  
Vol 618-619 ◽  
pp. 319-323 ◽  
Author(s):  
Parama Chakraborty Banerjee ◽  
Tao Sun ◽  
Jonathan H.W. Wong ◽  
Min Wang

To improve the biocompatibility and bioactivity of NiTi shape memory alloy (SMA), apatite/collagen composite coatings were fabricated on the surface of NiTi SMA at room temperature using the electrochemical deposition technique. Spherical apatite particles and fibrous collagen that formed the composite coating were visible under scanning electron microscope (SEM). The Ca/P ratio of the apatite component in the coating, as determined by energy dispersive X-ray spectroscopy (EDX), was about 1.38 which is slightly higher than that of octocalcium phosphate (OCP). X-ray diffraction result showed that the apatite was amorphous, which was due to the low temperature (i.e., room temperature) deposition process. The structure of the composite coatings was further characterized using Fourier transform infrared reflection spectroscopy (FTIR). It was also found that, compared to bare NiTi SMA samples, the wettability of as-deposited samples was increased because of the formation of the composite coating.


2015 ◽  
Vol 36 (6) ◽  
pp. 3897
Author(s):  
Flávio Moreira de Almeida ◽  
José Augusto Gomes Azevêdo ◽  
Ícaro Dos Santos Cabral ◽  
Luiz Gustavo Ribeiro Pereira ◽  
Gherman Garcia Leal de Araújo ◽  
...  

The objective was to evaluate the parameters of kinetics of ruminal fermentation of cocoa husks (CH) treated with alkali and thermal agents, using the semi-automated in vitro gas production technique. Cocoa husks samples were subjected to alkali and thermal methods (effect of time of exposure) treatment, as follows: control; alkaline treatment with calcium hydroxide ((Ca(OH)2) and calcium oxide (CaO), both doses of 15.0; 30.0 and 45.0 g kg-1 of CH; heat treatment in an autoclave at a pressure of 1.23 kg cm-2 (15 psi) and a temperature of 123°C for 30, 60 and 90 minutes. For statistical analysis, orthogonal contrasts and regression. The degradation rate and the final volume of gases of non-fiber carbohydrates decreased with the addition of Ca(OH)2 and CaO, however, for fibrous carbohydrates effects were positive. For each percentage of Ca(OH)2 and CaO included, it is estimated an increase of 5.74 and 2.9% in the final volume of the fiber, respectively. When the heat treatment, a decrease in all parameters was estimated. For each minute of exposure to heat, there was a decrease of 0.4% in total final volume of gases. The alkali treatment can be an efficient alternative for improving the digestibility of fibrous fractions of CH.


2014 ◽  
Vol 783-786 ◽  
pp. 713-720
Author(s):  
Paolo Matteis ◽  
Giorgio Scavino ◽  
R. Sesana ◽  
F. D’Aiuto ◽  
Donato Firrao

The automotive TWIP steels are high-Mn austenitic steels, with a relevant C content, which exhibit a promising combination of strength and toughness, arising from the ductile austenitic structure, which is strengthened by C, and from the TWIP (TWinning Induced Plasticity) effect. The microstructure of the low-alloy Q&P steels consists of martensite and austenite and is obtained by the Quenching and Partitioning (Q&P) heat treatment, which consists of: austenitizing; quenching to the Tqtemperature, comprised between Msand Mf; soaking at the Tppartitioning temperature (Tpbeing equal to or slightly higher than Tq) to allow carbon to diffuse from martensite to austenite; and quenching to room temperature. The fatigue behavior of these steels is examined both in the as-fabricated condition and after pre-straining and welding operations, which are representative of the cold forming and assembling operations performed to fabricate the car-bodies. Moreover, the microscopic fracture mechanisms are assessed by means of fractographic examinations.


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