Stability and corrosion resistance of superhydrophobic surface on oxidized aluminum in NaCl aqueous solution

AA6063-TiC composites have several weight percentages up to 9 wt. % were fabricated by using stir casting route method. The effects of the weight percentage of TiC particles on the microstructures and corrosion behavior of AA6063-TiC composites were studied. The results revealed that the AA6063-TiC composites exhibited higher density than the AA6063 matrix. The accelerated corrosion tests of AA6063-TiC composites in 3.5 wt. % NaCl aqueous solution at room temperature, the AA6063-TiC composites have better corrosion resistance than the AA6063 matrix. Increasing the weight percentage of the TiC particles to reduces the corrosion rate of the AA6063-TiC composites. In this process corrosion rate of 0.4402 mm/year for AA6063 matrix, 0.3891 mm/year for 3 wt. % , 0.3568 mm/year for 6 wt. % and 0.3062 mm/year for 9 wt. % of TiC particles respectively. The poor corrosion resistance of the composites can be attributed to the galvanic effects between the AA6063 matrix and TiC reinforcement.

Download Full-text

Corrosion Resistance Evaluation of a Stainless-Steel Brazed Joint in HCl Solution

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1016.997 ◽

2021 ◽

Vol 1016 ◽

pp. 997-1002

Author(s):

Hikaru Nagata ◽

Masa Ono ◽

Yasuyuki Miyazawa ◽

Yuji Hayashi ◽

Yoshio Bizen

Keyword(s):

Aqueous Solution ◽

Stainless Steel ◽

Corrosion Resistance ◽

Base Metal ◽

Corrosion Behavior ◽

Anodic Polarization ◽

Filler Metal ◽

Brazed Joint ◽

In Situ Observations

To clarify the effect of the acid solution type on corrosion resistance, the corrosion behavior of stainless steel brazed joints in HCl aqueous solution was evaluated through electrochemical measurements. Anodic polarization curves of a ferritic stainless-steel base metal, Ni-based brazing filler metals, and a brazed joint were recorded. In addition, in situ observations were conducted to observe the corrosion behavior of each structure of the brazed joint. Corrosion potentials of the brazing filler metal were lower than that of the base metal. In situ observations of the brazed joint revealed the order of corrosion in aqueous hydrochloric acid. According to the electrochemical measurements, under an actual corrosive environment, the brazing filler metal can function as an anode and selectively corrode. In addition, the anodic polarization curve of the brazed joint showed values between those of the polarization curves of the brazing filler metal and the base metal, indicating that the corrosion resistance could be electrochemically evaluated in HCl aqueous solution.

Download Full-text

Structure, phase transformation and corrosion resistance of CrAlN/CN composite multilayer films in NaCl aqueous solution

Ceramics International ◽

10.1016/j.ceramint.2019.08.169 ◽

2019 ◽

Vol 45 (18) ◽

pp. 24446-24452 ◽

Cited By ~ 3

Author(s):

Dongguang Liu ◽

Haoran Ma ◽

Heng Li ◽

Yan Liang

Keyword(s):

Aqueous Solution ◽

Corrosion Resistance ◽

Phase Transformation ◽

Multilayer Films ◽

Structure Phase

Download Full-text

Preparation of Superhydrophobic Steel Surfaces with Chemical Stability and Corrosion

Coatings ◽

10.3390/coatings9060398 ◽

2019 ◽

Vol 9 (6) ◽

pp. 398 ◽

Cited By ~ 8

Author(s):

Chongwei Du ◽

Xiaoyan He ◽

Feng Tian ◽

Xiuqin Bai ◽

Chengqing Yuan

Keyword(s):

Contact Angle ◽

Corrosion Resistance ◽

Carbon Steel ◽

Chemical Stability ◽

Superhydrophobic Surface ◽

Contact Angle Hysteresis ◽

Water Contact ◽

Simple Method ◽

Q235 Carbon Steel ◽

Steel Surfaces

Corrosion seriously limits the long-term application of Q235 carbon steel. Herein, a simple fabrication method was used to fabricate superhydrophobic surfaces on Q235 carbon steel for anticorrosion application. The combination of structure and the grafted low-surface-energy material contributed to the formation of superhydrophobic steel surfaces, which exhibited a water contact angle of 161.6° and a contact angle hysteresis of 0.8°. Meanwhile, the as-prepared superhydrophobic surface showed repellent toward different solutions with pH ranging from 1 to 14, presenting excellent chemical stability. Moreover, the acid corrosive liquid (HCl solution with pH of 1) maintained sphere-like shape on the as-prepared superhydrophobic surface at room temperature, indicating superior corrosion resistance. This work provides a simple method to fabricate superhydrophobic steel surfaces with chemical stability and corrosion resistance.

Download Full-text

Effect of Al Content in the Mg-Based Alloys on the Composition and Corrosion Resistance of Composite Hydroxide Films Formed by Steam Coating

Materials ◽

10.3390/ma12071188 ◽

2019 ◽

Vol 12 (7) ◽

pp. 1188 ◽

Cited By ~ 1

Author(s):

Takahiro Ishizaki ◽

Tomohiro Miyashita ◽

Momo Inamura ◽

Yuma Nagashima ◽

Ai Serizawa

Keyword(s):

Aqueous Solution ◽

Corrosion Resistance ◽

Treatment Time ◽

Mg Alloys ◽

Mg Alloy ◽

Potential Range ◽

Protective Film ◽

Al Content ◽

Passive Behavior ◽

Superior Corrosion Resistance

Mg alloys are expected to be used in fields of the transportation industry because of their lightweight property, however, they show low corrosion resistance. To improve the corrosion resistance, preparation of the protective film on Mg alloys is essential. In this study, composite hydroxide films were prepared on three types of Mg alloys with different aluminum contents—that is, AZ31, AZ61, and AZ91D—by steam coating to investigate the relationship between the Mg-Al layered double hydroxide (LDH) content in the film and the Al content in the Mg alloys. Scanning electron microscopy (SEM) observation demonstrated that films were formed densely on all Mg alloy surfaces. X-ray diffraction (XRD) analyses revealed that all films prepared on AZ61 and AZ91D were composed of Mg(OH)2, AlOOH, and Mg-Al LDH, while the film containing Mg(OH)2 and Mg-Al LDH were formed only on AZ31. The Mg-Al LDH content in the film prepared on AZ61 was relatively higher than those prepared on AZ31 and AZ91D. The content of AlOOH in the film increased with an increase in the Al content in the Mg alloys. The film thickness changed depending on the treatment time and type of Mg alloy. Polarization curve measurements in 5 mass% NaCl solution demonstrated that the film prepared on the AZ61 showed complete passive behavior within the potential range of −1.0 to −0.64 V. In addition, immersion tests in 5 mass% NaCl aqueous solution for 480 h demonstrated that the film on the AZ61 had superior durability against 5 mass% NaCl aqueous solution. These results indicated that the film on the AZ61 had the most superior corrosion resistance among all samples. The results obtained in this study suggest that the LDH content in the film could be related to the corrosion resistance of the film.

Download Full-text