Effect of NaOH Concentration on the Microhardness and Corrosion Resistance of Titanium by Acid-Hydrothermal Method

2018 ◽  
pp. 467-475
Author(s):  
Ying Xu ◽  
Bian Wang ◽  
Yanqing Cai ◽  
Zizi Zhang
Keyword(s):  
Corrosion Resistance ◽  
Hydrothermal Method

scholarly journals Controllable Synthesis of Nanostructured Ca-P Coating on Magnesium Alloys via Sodium Citrate Template-Assisted Hydrothermal Method and Its Corrosion Resistance

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1232
Author(s):  
Jieling Wei ◽  
Shu Cai ◽  
Qianqian Li ◽  
Yao Xie ◽  
Xiaogang Bao ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Hydrothermal Method ◽  
Sodium Citrate ◽  
Az31 Alloy ◽  
Complexation Reaction ◽  
Controllable Synthesis ◽  
High Corrosion Resistance ◽  
Ha Coating ◽  
Existing Form ◽  
Rate Requirement

In this study, a nanostructured needle-like hydroxyapatite (HA) coating was prepared by the sodium citrate template-assisted hydrothermal method on magnesium alloy (AZ31). The influence of sodium citrate on the composition, microstructure and corrosion behavior of the coatings was studied. The results showed that with the increase in the mole ratio of Ca/sodium citrate from 1 to 13, the coating gradually changed from the needle-like morphology of HA to the flake morphology of β-tricalcium phosphate (β-TCP), which was related to the existing form of citrate in the solution and the trend of complexation reaction. When the mole ratio of Ca/sodium citrate was 1, the HA coating sample with the nano needle-like morphology had a high corrosion resistance (Rt = 235.300 ± 3.584 kΩ·cm2), which was almost 200 times that of the naked AZ31 alloy. Moreover, the corrosion rates of the Ca-P coated AZ31 alloy stabilized at about 0.55 mm/year and could provide more than 56 days of corrosion protection to the samples, which approximated the degradation rate requirement for biomaterials used as bone fixture.

Microstructure and Corrosion Resistance of TiO2 Films on 316L Using Hydrothermal Method

2014 ◽  
Vol 670-671 ◽  
pp. 271-274
Author(s):  
Jun Wang ◽  
Long Huang
Keyword(s):  
Corrosion Resistance ◽  
Hydrothermal Method ◽  
316L Stainless Steel ◽  
Anatase Phase ◽  
Corrosion Current ◽  
Visible Range ◽  
X Ray Diffraction ◽  
Stainless Steel 316L ◽  
X Ray ◽  
Tafel Polarization

TiO2 films were prepared on glass and 316L stainless steel (316L SS) using hydrothermal method. The microstructures of the films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It indicated that the films crystallized as anatase phase with mirror-like surface morphology. The optical properties of the TiO2 film were studied by Ultraviolet Visible Spectroscopy (UV-Vis). The results showed that the film was transparent in visible range. The cut-off point of the sample was red-shifted after annealed treatment. The corrosion resistance of the film was evaluated by using Tafel polarization curve in simulated body solution. The corrosion current density was decreased from 8.556 μA/cm2 (316L SS) to 1.421 μA/cm2 (TiO2 film/316L SS). While, the corrosion potential was increased from-0.402 V (316L SS) to-0.325 V (TiO2 film/316L SS). The 316L SS with TiO2 film has better corrosion resistance.

The research on preparation of superhydrophobic surfaces of pure copper by hydrothermal method and its corrosion resistance

2018 ◽  
Vol 270 ◽  
pp. 310-318 ◽  
Author(s):  
Yunxiao Wan ◽  
Mojing Chen ◽  
Wei Liu ◽  
XiXun Shen ◽  
Yulin Min ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Hydrothermal Method ◽  
Pure Copper ◽  
Superhydrophobic Surfaces

Microstructures of Ti-1.5 w/o Ni Alloys with Mo and A1 Additions

1975 ◽  
Vol 33 ◽  
pp. 54-55
Author(s):  
Anna C. Fraker
Keyword(s):  
Corrosion Resistance ◽  
Beneficial Effect ◽  
Crevice Corrosion ◽  
Local Corrosion ◽  
Precipitate Size ◽  
Ni Alloys

Small amounts of nickel are added to titanium to improve the crevice corrosion resistance but this results in an alloy which has sheet fabrication difficulties and is subject to the formation of large Ti2Ni precipitates. These large precipitates can serve as local corrosion sites; but in a smaller more widely dispersed form, they can have a beneficial effect on crevice corrosion resistance. The purpose of the present work is to show that the addition of a small amount of Mo to the Ti-1.5Ni alloy reduces the Ti2Ni precipitate size and produces a more elongated grained microstructure. It has recently been reported that small additions of Mo to Ti-0.8 to lw/o Ni alloys produce good crevice corrosion resistance and improved fabrication properties.

Role of Aluminium on the Microstructure and Corrosion Behaviour of Magnesium Prepared by Powder Metallurgy Method

2020 ◽  
Vol 17 (3) ◽  
pp. 8206-8213
Author(s):  
J. Alias
Keyword(s):  
Corrosion Resistance ◽  
Powder Metallurgy ◽  
Corrosion Behaviour ◽  
Corrosion Current ◽  
Optical Microscope ◽  
High Reactivity ◽  
Aluminium Content ◽  
Powder Metallurgy Method ◽  
X Ray Diffraction ◽  
Promising Development

Much research on magnesium (Mg) emphasises creating good corrosion resistance of magnesium, due to its high reactivity in most environments. In this study, powder metallurgy (PM) technique is used to produce Mg samples with a variation of aluminium (Al) composition. The effect of aluminium composition on the microstructure development, including the phase analysis was characterised by optical microscope (OM), scanning electron microscopy (SEM) and x-ray diffraction (XRD). The mechanical property of Mg sample was performed through Vickers microhardness. The results showed that the addition of aluminium in the synthesised Mg sample formed distribution of Al-rich phases of Mg17Al12, with 50 wt.% of aluminium content in the Mg sample exhibited larger fraction and distribution of Al-rich phases as compared to the 20 wt.% and 10 wt.% of aluminium content. The microhardness values were also increased at 20 wt.% and 50 wt.% of aluminium content, comparable to the standard microhardness value of the annealed Mg. A similar trend in corrosion resistance of the Mg immersed in 3.5 wt.% NaCl solution was observed. The corrosion behaviour was evaluated based on potentiodynamic polarisation behaviour. The corrosion current density, icorr, is observed to decrease with the increase of Al composition in the Mg sample, corresponding to the increase in corrosion resistance due to the formation of aluminium oxide layer on the Al-rich surface that acted as the corrosion barrier. Overall, the inclusion of aluminium in this study demonstrates the promising development of high corrosion resistant Mg alloys.

Sign in / Sign up

Export Citation Format

Share Document