scholarly journals Systematic Control of Anodic Aluminum Oxide Nanostructures for Enhancing the Superhydrophobicity of 5052 Aluminum Alloy

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3231 ◽  
Author(s):  
Chanyoung Jeong ◽  
Hyejeong Ji
Keyword(s):  
Aluminum Alloy ◽  
Solid Fraction ◽  
Hierarchical Structures ◽  
Superhydrophobic Surfaces ◽  
Self Assembled Monolayer ◽  
Oxide Nanostructures ◽  
Pore Widening ◽  
The Relationship ◽  
Systematic Control ◽  
Mild Anodization

The recent increased interest in the various applications of superhydrophobic surfaces necessitates investigating ways of how this property can be enhanced further. Thus, this study investigated how superhydrophobic properties can be enhanced through the formation of anodic alumina nanostructures on 5052 aluminum alloy. A multistep anodizing process that alternates two different anodizing modes, mild anodization (MA) and hard anodization (HA), with an intermediate pore-widening (PW) process was employed. Multistep anodization was employed in two different ways: an MA → PW → HA process and an HA → PW → MA process. Both routes were conducted with PW durations of 40, 50, and 60 min. The well-defined nanostructures were coated with a self-assembled monolayer (SAM) of FDTS (1H, 1H, 2H, 2H-perfluorodecyltrichlorosilane). The contact angle values of water droplets were maximized in the pillar-like nanostructures, as they have a less solid fraction than porous nanostructures. With this, the study demonstrated the formation mechanism of both nanoscale pillar and nanoscale hierarchical structures, the wettability of the superhydrophobic surfaces, and the relationship between PW duration time with wettability and the solid fraction of the superhydrophobic surfaces.

Eco-friendly and facile fabrication of superhydrophobic aluminum alloy

2021 ◽  
pp. 135065012110283
Author(s):  
Jayanth Ivvala ◽  
Priya Mandal ◽  
Harpreet Singh Arora ◽  
Harpreet Singh Grewal
Keyword(s):  
Contact Angle ◽  
Aluminum Alloy ◽  
Large Scale ◽  
Prolonged Exposure ◽  
Contact Angle Hysteresis ◽  
Hierarchical Structures ◽  
Superhydrophobic Surfaces ◽  
Developed Surface ◽  
Vapor Deposition Technique ◽  
Self Cleaning

Synthetic superhydrophobic surfaces have drawn significant interest owing to their water-resistant and self-cleaning applications. However, most of the fabrication practices involve complex processes that are unsustainable to withstand large-scale fabrication to transform into standard industrial practice. The desired durability of these surfaces is another crucial challenge that makes the translation of these products difficult. In this paper, we reported the fabrication of superhydrophobic aluminum alloy with a simpler, low-cost, and eco-friendly technique using the hydrothermal treatment. Subsequently, the surface energy of the processed substrate was modulated using a chemical vapor deposition technique. The developed surface shows an extreme water repellency with a contact angle above 160° and a very low contact angle hysteresis and rolling angle (<5°). Surface morphological characterizations showed the formation of nanoscale hierarchical structures which resulted in a stable Cassie state due to the effective entrapment of air and exhibiting self-cleaning ability. The developed surface showed extreme wetting resilience during exposure to a droplet impingement with an impinging velocity of >2 m/s. Further, these superhydrophobic surfaces were exposed to atmospheric weather conditions to check their robustness. During a rain simulator testing, a developed surface showed low contact angle hysteresis (<10°) after enduring multiple cycles. The processed surface also showed significant de-wetting behavior during condensation experiments and chemical resistance under prolonged exposure. Weathering tests performed under outdoor conditions showed an insignificant influence on the de-wettability of the processed sample. The present study highlights the fabrication of superhydrophobic durable metallic surfaces through a facile and green fabrication route for multifunctional applications.

Contact Angle of Nepenthes alata Slippery Zone: Results from Measurement and Model Analysis

2021 ◽  
pp. 1-7
Author(s):  
Lixin Wang ◽  
Pan Pan ◽  
Shixing Yan ◽  
Shiyun Dong
Keyword(s):  
Contact Angle ◽  
Hierarchical Structures ◽  
Model Analysis ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Structure Characteristic ◽  
Baxter Equation ◽  
Measured Contact Angle ◽  
The Relationship ◽  
Contact Angle Analysis

The slippery zone of Nepenthes alata depends on its highly evolved morphology and structure to show remarkable superhydrophobicity, which has gradually become a biomimetic prototype for developing superhydrophobic materials. However, the mechanism governing this phenomenon has not been fully revealed through model analysis. In this paper, the superhydrophobicity of slippery zone is studied by contact angle measurement, morphology/structure examination and model analysis. The slippery zone causes ultrapure water droplet to produce a considerably high contact angle (155.11–158.30°), and has a micro-nano scale hierarchical structures consisting of lunate cells and wax coverings. According to the Cassie-Baxter equation and a self-defined infiltration coefficient, a model was established to analyze the effect of structure characteristic on the contact angle. Analysis result showed that the calculated contact angle (154.67–159.49°) was highly consistent with the measured contact angle, indicating that the established model can quantitatively characterize the relationship between the contact angle and the structure characteristic. Our study provides some evidences to further reveal the superhydrophobic mechanism of Nepenthes alata slippery zone, as well as inspires the biomimetic development of superhydrophobic surfaces.

scholarly journals Preparation of superhydrophobic surfaces with micro/nano alumina molds

RSC Advances ◽  
2018 ◽  
Vol 8 (64) ◽  
pp. 36697-36704 ◽  
Author(s):  
Takashi Yanagishita ◽  
Kaito Murakoshi ◽  
Toshiaki Kondo ◽  
Hideki Masuda
Keyword(s):  
Superhydrophobic Surface ◽  
Porous Alumina ◽  
Hierarchical Structures ◽  
Superhydrophobic Surfaces ◽  
Anodic Porous Alumina ◽  
Nano Alumina

Superhydrophobic surface with hierarchical structures prepared by nanoimprinting using anodic porous alumina molds.

Wetting and Dewetting Transitions on Submerged Superhydrophobic Surfaces with Hierarchical Structures

Langmuir ◽  
2016 ◽  
Vol 33 (1) ◽  
pp. 407-416 ◽  
Author(s):  
Huaping Wu ◽  
Zhe Yang ◽  
Binbin Cao ◽  
Zheng Zhang ◽  
Kai Zhu ◽  
...  
Keyword(s):  
Hierarchical Structures ◽  
Superhydrophobic Surfaces

Apparent Viscosity and Rheological Behavior of Aluminum-Alloy Slurry Containing Nano-Sized SiC Particles

2019 ◽  
Vol 285 ◽  
pp. 391-397
Author(s):  
Kang Lu ◽  
Shu Sen Wu ◽  
Shu Lin Lü ◽  
Chong Lin
Keyword(s):  
Aluminum Alloy ◽  
Rheological Behavior ◽  
Apparent Viscosity ◽  
Mass Fraction ◽  
Matrix Alloy ◽  
Rotating Cylinder ◽  
Viscous Force ◽  
Semi Solid ◽  
The Relationship ◽  
Cylinder Viscometer

The apparent viscosity and rheological behavior of nanoSiCP/Al-5Cu composites were studied by using a high temperature coaxial rotating cylinder viscometer. The results show that mass fraction of nanoSiCP is an important factor for apparent viscosity of the nanoSiCP/Al-5Cu composites, and there is a great enhancement of apparent viscosity of the slurry with the increase of nanoSiCp content. It can attribute to the viscous force between nanoSiCp and matrix alloy melt above the liquidus. The increased amplitude of apparent viscosity in semi-solid state is far less than those in liquid state with the increase of mass fraction of nanoSiCp. The apparent viscosities of the composites reinforced with 0.5%, 1%, 1.5% and 2% nanoSiCp at 700°C were 24.78%, 95.25%, 160.29% and 228.62% higher than that of Al-5Cu alloy, respectively. Besides, the rheological model of nanoSiCP/Al-5Cu composites was established based on the fitting curve, which can precisely describe the relationship between the apparent viscosity of nanocomposites slurry and nanoSiCp mass fraction.

scholarly journals Modeling and Optimization of Bidirectional Clamping Forces in Drilling of Stacked Aluminum Alloy Plates

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2866
Author(s):  
Jintong Liu ◽  
Anan Zhao ◽  
Piao Wan ◽  
Huiyue Dong ◽  
Yunbo Bi
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Aluminum Alloy ◽  
Clamping Force ◽  
Practical Application ◽  
Element Simulation ◽  
Theory Of Plates ◽  
Plates And Shells ◽  
The Mathematical Model ◽  
The Relationship

Interlayer burrs formation during drilling of stacked plates is a common problem in the field of aircraft assembly. Burrs elimination requires extra deburring operations which is time-consuming and costly. An effective way to inhibit interlayer burrs is to reduce the interlayer gap by preloading clamping force. In this paper, based on the theory of plates and shells, a mathematical model of interlayer gap with bidirectional clamping forces was established. The relationship between the upper and lower clamping forces was investigated when the interlayer gap reaches zero. The optimization of the bidirectional clamping forces was performed to reduce the degree and non-uniformity of the deflections of the stacked plates. Then, the finite element simulation was conducted to verify the mathematical model. Finally, drilling experiments were carried out on 2024-T3 aluminum alloy stacked plates based on the dual-machine-based automatic drilling and riveting system. The experimental results show that the optimized bidirectional clamping forces can significantly reduce the burr heights. The work in this paper enables us to understand the effect of bidirectional clamping forces on the interlayer gap and paves the way for the practical application.

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