scholarly journals One-Step Preparation of Super-Hydrophobic Micro-Nano Dendrites on Al Alloy for Enhanced Corrosion Resistance

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 960 ◽  
Author(s):  
Xuewu Li ◽  
Tian Shi ◽  
Ben Li ◽  
Chuanwei Zhang ◽  
Bin Zhong ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Low Cost ◽  
Hydrophobic Surface ◽  
Al Alloys ◽  
Al Alloy ◽  
Ocean Engineering ◽  
Acid Modification ◽  
Sliding Angle ◽  
Corrosion Failure ◽  
One Step

Corrosion failure is a thorny issue that restricts the applications of Al alloys. As a research hotspot in functional realization, hydrophobic fabrication exactly offers an efficient method to settle metallic corrosions. This work has developed a facile and low-cost method to enhance corrosion resistance of Al alloys. The micro-nano dendrites have been firstly prepared on metallic substrate using one-step potentiostatic deposition. Then, wetting and electrochemical behaviors have been systematically investigated after stearic acid modification. Results show that the as-prepared surface possesses amplified and durable water repellence with an apparent contact angle (CA) of 154.2° and a sliding angle (SA) of 4.7°. Meanwhile, owing to the trapped air in dendrites, the newly-generated solid-air-liquid interfaces help to resist seawater penetration by reducing interfacial interactions on the super-hydrophobic surface as well as significantly enhance its corrosion resistance. This work sheds positive insights into extending the applications of Al alloys in many areas, especially for ocean engineering fields.

scholarly journals One-Step Potentiostatic Deposition of Micro-Particles on Al Alloy as Superhydrophobic Surface for Enhanced Corrosion Resistance by Reducing Interfacial Interactions

Coatings ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 392 ◽  
Author(s):  
Tian Shi ◽  
Xuewu Li ◽  
Qiaoxin Zhang ◽  
Ben Li
Keyword(s):  
Corrosion Resistance ◽  
Al Alloys ◽  
Water Repellent ◽  
Al Alloy ◽  
Interfacial Interactions ◽  
Sliding Angle ◽  
Water Contact ◽  
Corrosion Failure ◽  
Micro Particles ◽  
One Step

Corrosion failure is a thorny problem that restricts the application of Al alloys. As a new technique for functional realization, hydrophobic preparation offers an efficient approach to solve corrosion problem. This work has developed a facile and low-cost method to endow Al alloy with enhanced water-repellent and anticorrosion abilities. The micro-particles have been firstly prepared by one-step deposition process. Furthermore, wetting and electrochemical behaviors of as-prepared structures have been investigated after silicone modification. Results show that the fabricated surface possesses excellent superhydrophobicity with a water contact angle (CA) of 154.7° and a sliding angle (SA) of 6.7°. Meanwhile, the resultant surface is proved with enhanced corrosion resistance by reducing interfacial interactions with seawater, owing to newly-generated solid-air-liquid interfaces. This work sheds positive insights into extending applications of Al alloys, especially in oceaneering fields.

Effects of the Duration of Potentiostatic Anodizing on the Corrosion Resistance and Surface Morphology of Films Formed on Mg-Al Alloys

2005 ◽  
Vol 486-487 ◽  
pp. 125-128 ◽  
Author(s):  
Seong Jong Kim ◽  
Seok Ki Jang ◽  
Jeong Il Kim
Keyword(s):  
Corrosion Resistance ◽  
Surface Morphology ◽  
Anodic Oxide ◽  
Al Alloys ◽  
Anodic Film ◽  
Al Alloy ◽  
Active Dissolution ◽  
Dissolution Reaction ◽  
Alloy Az91 ◽  
Morphology Of Films

The effects of the duration of potentiostatic anodizing on the corrosion resistance and surface morphology of anodic oxide films formed on Mg-Al alloy (AZ91) in 1 M NaOH were investigated. With the formation of an anodic film, the current density decreased gradually, started to stabilize at 300 s, and was relatively constant at 600 s. These results may be related to the increased time for catalysis of the active dissolution reaction, which not only enlarges the area covered by the anodic film, but also produces a more coherent, thicker film. The reference corrosion potentials of the anodic oxide film for AZ91 shifted in the noble direction with time. In general, the corrosion resistance characteristics were improved with anodizing time.

scholarly journals O PROCESSO DE ANODIZAÇÃO DO ALUMÍNIO E SUAS LIGAS: UMA ABORDAGEM HISTÓRICA E ELETROQUÍMICA

Química Nova ◽  
2021 ◽  
Author(s):  
João Araujo
Keyword(s):  
Low Cost ◽  
Industrial Applications ◽  
Al Alloys ◽  
Al Alloy ◽  
Duplex Structure ◽  
Acid Bath ◽  
Electrochemical Approach ◽  
Regular Arrangement ◽  
Natural Oxide ◽  
The Relationship

THE ANODIZING PROCESS OF ALUMINUM AND ITS ALLOYS: A HISTORICAL AND ELECTROCHEMICAL APPROACH. Al and its alloys are found in several industrial applications. However, like most metals, this material is not immune to corrosion, being necessary to be protected against corrosion. One of the methods most commonly employed to improve the corrosion resistance of Al alloys is the anodizing process, which consists of thickening of the natural oxide (Al2O3) presents in Al through anodic oxidation. The anodizing process is accomplished by immersion of the Al alloy into an acid bath and passing an electric current through it. This process produces two layers: a barrier layer thicker than the natural oxide and a layer with regular arrangement of nanopores (porous layer). This duplex structure forms the anodized layer with a large specific surface area. With the advent of nanotechnology, this layer has been applied in other areas due to its low cost, stability, absence of toxicity, and biocompatibility. In this context, this paper addresses a historical and electrochemical review of the anodizing process of Al and its alloys, presenting the main events that culminated in the development of the current processes and the understanding of the relationship between the chemical reactions and the mechanisms that occur during nucleation and development of the oxide layer

Microstructure and Mechanical Properties of Fe-Containing Al-Alloys Processed by a Rheo-Diecasting Process

2006 ◽  
Vol 519-521 ◽  
pp. 1251-1256
Author(s):  
X. Fang ◽  
G. Shao ◽  
Z. Fan
Keyword(s):  
Mechanical Properties ◽  
High Efficiency ◽  
Low Cost ◽  
Al Alloys ◽  
Experimental Results ◽  
Semisolid Slurry ◽  
Al Alloy ◽  
Twin Screw ◽  
Size And Morphology ◽  
Plate Morphology

Al-Fe compounds are usually present in the as-cast microstructure of Al-alloys as large needles or plates. As such, they have a detrimental effect on the mechanical properties of Al-alloys containing Fe, either as an impurity element or as an alloying addition. However, Fe-containing Al-alloys also offer attractive physical properties, such as improved stiffness, wear resistance and thermal resistance. If the needle and plate morphology of the Al-Fe compounds can be modified to a more compact morphology, with refined particle size and uniform distribution, the mechanical properties of Al-Fe based Al-alloys can be substantially improved, and therefore, they will find wider applications in many engineering sectors. A new semisolid metal processing technology, rheodiecasting (RDC), has been developed for production of Al-alloy components with high integrity. The RDC process innovatively combines the dispersive mixing power of the twin-screw mechanism, for the creation of high quality semisolid slurry, with the high efficiency, low cost nature of the high-pressure diecasting (HPDC) process for component shaping. In this paper, we present our experimental results on the effects of intensive melt shearing on the size and morphology of Al-Fe compounds in A380 alloys, with different levels of Fe additions. The experimental results have shown that intensive melt shearing during solidification can effectively change the particle shape from the usual needles and plates, to an equiaxed morphology. Samples which have undergone with melt shearing, exhibit much improved strength and ductility compared to those with the same level of Fe addition, but without exposure to melt shearing.

One-step synthesis and deposition of few-layer graphene via facile, dry ball-free milling

MRS Advances ◽  
2017 ◽  
Vol 2 (15) ◽  
pp. 847-856 ◽  
Author(s):  
Abdul Hai Alami ◽  
Kamilia Aokal ◽  
Mhd Adel Assad ◽  
Di Zhang ◽  
Hussain Alawadhi ◽  
...  
Keyword(s):  
Low Cost ◽  
High Vacuum ◽  
Chemical Vapor ◽  
Hydrophobic Surface ◽  
Graphite Powder ◽  
High Energy ◽  
Layer Graphene ◽  
Wide Range ◽  
One Step ◽  
Few Layer Graphene

ABSTRACTGraphene is a 2-D carbon material showing considerable prominence in a wide range of optoelectronics, energy storage, thermal and mechanical applications. However, due to its unique features which are typically associated with difficulty in handling (ultra-thin thickness and hydrophobic surface, to name a few), synthesis and subsequent deposition processes are thus critical to the material properties of the prepared graphene films. While existing synthesis approaches such as chemical vapor deposition and epitaxial growth can grow graphene with high degree of order, the costly high temperature and/or high vacuum process prohibit the widespread usage, and the subsequent graphene transfer from the growth substrates for deposition proves to be challenging. Herein, a low-cost one-step synthesis and deposition approach for preparing few-layer graphene (FLG) on flexible copper substrates based on dry ball-free milling of graphite powder is proposed. Different from previous reports, copper substrates are inserted into the milling crucible, thus accomplishing simultaneous synthesis and deposition of FLG and eliminating further deposition step. Furthermore, while all previously reported high energy milling processes involve using balls of various sizes, we adopt a ball-free milling process relying only on centrifugal forces, which significantly reduces the surface damage of the deposition substrates. Sample characterization indicates that the process yields FLG deposited uniformly across all tested specimens. Consequently, this work takes graphene synthesis and deposition a step closer to full automation with simple and low-cost process.

A One-Step Pack Cementation Method for Preparing AlN/Aluminizing Coating with Good Corrosion Resistance

2019 ◽  
Vol 295 ◽  
pp. 3-8
Author(s):  
Xiao Yan Wang ◽  
Jiao Jiao Du ◽  
Zhong Wei Ma
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Low Cost ◽  
Electrochemical Measurement ◽  
Industrial Applications ◽  
Pack Cementation ◽  
Diffraction Spectrum ◽  
X Ray ◽  
Good Corrosion Resistance ◽  
One Step

AlN/aluminizing coating with good corrosion resistance on carbon steel was prepared by one-step powder pack method. The phase compositions were analyzed by X-Ray diffraction spectrum (XRD). The cross-sections were investigated by scanning electron microscope (SEM) equipped with an energy dispersive X-ray spectrometer (EDS). According the analysis above, the appropriate powder formula and technological parameter were determined: 40 wt.% Al + 50 wt.%Al2O3 + 5 wt.% NH4Cl + 5 wt.%CeO2, heating from 800 °C and maintaining at 900 °C for 6 hours. The corrosion resistance of specimen with AlN/aluminizing coating were measured by electrochemical test. The electrochemical measurement suggested that the corrosion resistance property of carbon steel was remarkably improved by fabricating AlN/aluminizing film. The process of pack cementation method in this fabrication is very simple, low-cost and facile, which opens a promising and effective path for industrial applications for AlN/aluminizing coating on various metallic materials.

Low-cost one-step fabrication of superhydrophobic surface on Al alloy

2011 ◽  
Vol 257 (18) ◽  
pp. 7928-7931 ◽  
Author(s):  
Youfa Zhang ◽  
Jie Wu ◽  
Xinquan Yu ◽  
Hao Wu
Keyword(s):  
Superhydrophobic Surface ◽  
Low Cost ◽  
Al Alloy ◽  
One Step

A new, bright and hard aluminum surface produced by anodization

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744029
Author(s):  
Fengyan Hou ◽  
Bo Hu ◽  
See Leng Tay ◽  
Yuxin Wang ◽  
Chao Xiong ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Metal Salt ◽  
Salt Spray ◽  
Processing Parameters ◽  
Al Alloys ◽  
Aluminum Surface ◽  
Al Alloy ◽  
Anodized Aluminum ◽  
Controlled Processing ◽  
Wide Range

Anodized aluminum (Al) and Al alloys have a wide range of applications. However, certain anodized finishings have relatively low hardness, dull appearance and/or poor corrosion resistance, which limited their applications. In this research, Al was first electropolished in a phosphoric acid-based solution, then anodized in a sulfuric acid-based solution under controlled processing parameters. The anodized specimen was then sealed by two-step sealing method. A systematic study including microstructure, surface morphology, hardness and corrosion resistance of these anodized films has been conducted. Results show that the hardness of this new anodized film was increased by a factor of 10 compared with the pure Al metal. Salt spray corrosion testing also demonstrated the greatly improved corrosion resistance. Unlike the traditional hard anodized Al which presents a dull-colored surface, this newly developed anodized Al alloy possesses a very bright and shiny surface with good hardness and corrosion resistance.

scholarly journals Fabrication of Self-Cleaning Superhydrophobic Surfaces with Improved Corrosion Resistance on 6061 Aluminum Alloys

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 159 ◽  
Author(s):  
Xiaojuan Dong ◽  
Jianbing Meng ◽  
Yizhong Hu ◽  
Xiuting Wei ◽  
Xiaosheng Luan ◽  
...  
Keyword(s):  
Contact Angle ◽  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Superhydrophobic Surface ◽  
Al Alloy ◽  
Alloy Sample ◽  
Sliding Angle ◽  
Water Contact ◽  
Self Cleaning

Aluminum alloys are widely used, but they are prone to contamination or damage under harsh working environments. In this paper, a self-cleaning superhydrophobic aluminum alloy surface with good corrosion resistance was successfully fabricated via the combination of sand peening and electrochemical oxidation, and it was subsequently covered with a fluoroalkylsilane (FAS) film. The surface morphology, surface wettability, and corrosion resistance were investigated using a scanning electron microscope (SEM), an optical contact angle measurement, and an electrochemical workstation. The results show that binary rough structures and an FAS film with a low surface energy on the Al alloy surfaces confer good superhydrophobicity with a water contact angle of 167.5 ± 1.1° and a sliding angle of 2.5 ± 0.7°. Meanwhile, the potentiodynamic polarization curve shows that the corrosion potential has a positively shifted trend, and the corrosion current density decreases by three orders of magnitude compared with that of the original aluminum alloy sample. In addition, the chemical stability of the as-prepared superhydrophobic surface was evaluated by dripping test using solutions with different pH values for different immersion time. It indicates that the superhydrophobic surface could provide long-term corrosion protection for aluminum alloys. Consequently, the as-prepared superhydrophobic surface has excellent contamination resistance and self-cleaning efficacy, which are important for practical applications.

Corrosion of Fe3Al-4Cr Alloys at 1000°C in N2-0.1%H2S Gas

2018 ◽  
Vol 765 ◽  
pp. 173-177 ◽  
Author(s):  
Yu Ke Shi ◽  
Dong Bok Lee
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Xrd Analysis ◽  
Al Alloys ◽  
Corrosion Products ◽  
Al Alloy ◽  
Oxide Scales ◽  
Mixed Gas ◽  
Corrosion Rates

Pure Fe3Al and Fe3Al+4%Cr alloys were corroded at 1000 °C for up to 200 h in N2-0.1%H2S-mixed gas in order to study their corrosion behavior in H2S-containing atmosphere. The formed scales consisted primarily of α-Al2O3, FeAl2O4, and Fe2O3. In these oxide scales, hydrogen and sulfur dissolved according to the reaction; H2S→2H+S. Corrosion products of Cr were not identified in the scales from the XRD analysis, indicating that Cr dissolved in the oxide scales. Fe3Al+4%Cr alloy displayed poorer corrosion resistance than Fe3Al alloy, indicating that chromium accelerated the corrosion rates of Fe3Al alloys.

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