Formation and Corrosion Resistance of Micro-Arc Oxidation Coating on Equal-Channel Angular Pressed AZ91D Mg Alloy

Ma, Aibin; Lü, Fan; Zhou, Qi; Jiang, Jinghua; Song, Dandan; Zheng, Yuxi

doi:10.3390/met6120308

Cited by 7 publications

(4 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Not many research papers describe the mechanism of the MAO process for nanocrystalline materials after HEBM and consolidation. But there are some publications concerning materials subjected to a severe plastic deformation (SPD) process 44,45 …”

Section: Discussionmentioning

confidence: 99%

Development of tantalum with highly hydrophilic surface and antimicrobial properties obtained by micro‐arc oxidation process

et al. 2020

View full text Add to dashboard Cite

Tantalum (Ta) and its application in biomaterials has been attracting more and more attention recently. It can be considered as a material for hard tissue implants. This study focuses on antimicrobial and surface characterization of micro‐arc oxidized (MAO) nanocrystalline Ta compared with its microcrystalline equivalent. For the purposes of the investigation, x‐ray diffractometry (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), wetting analysis, optical profilometry, corrosion resistance measurement, and antimicrobial tests were performed. Nanocrystalline Ta was fabricated using high‐energy ball milling (HEBM) and pulse plasma sintering (PPS). The MAO process done at 250 V results in the formation of a porous oxide surface. An XRD analysis confirmed the presence of a Ta2O5 oxide layer. Based on the SEM pictures, the obtained oxide layer was approximately 3–4 μm thick for nanocrystalline Ta substrate. For microcrystalline Ta, the oxide layer was thinner, in the range of 0.3–0.6 μm. The analysis of polarization curves showed a significant improvement of corrosion resistance for MAO nanocrystalline Ta (2.62 × 10−8 A/cm2) versus not oxidized nanocrystalline Ta (1.20 × 10−5 A/cm2). The surface roughness of MAO nanocrystalline Ta proved to be several times higher than that of unoxidized Ta. Wetting analysis showed that the oxide layer on the nanocrystalline substrate is hydrophilic. This research provides detailed information about MAO microcrystalline and MAO nanocrystalline Ta antimicrobial activity against Staphylococcus aureus and Pseudomonas aeruginosa. A significant decrease of S. aureus for MAO nanocrystalline Ta (control 10,435 ± 981 vs. sample 3,453 ± 130) was noticed. No significant difference was noticed for MAO microcrystalline and nanocrystalline Ta tested for P. aeruginosa.

show abstract

Section: Discussionmentioning

confidence: 99%

Development of tantalum with highly hydrophilic surface and antimicrobial properties obtained by micro‐arc oxidation process

et al. 2020

View full text Add to dashboard Cite

show abstract

“…AZ91D is one of the most widely used magnesium alloys for casting as it possesses a good combination of mechanical properties and castability [2]. Extensive research has been conducted to optimize die casting parameters [3,4] and improve mechanical properties [5,6] and corrosion resistance [7][8][9][10][11][12] of AZ91D magnesium alloys.…”

Section: Introductionmentioning

confidence: 99%

Mechanisms of Cracking in Laser Welding of Magnesium Alloy AZ91D

Zhou

Aprilia

Mark

2021

Metals

View full text Add to dashboard Cite

Considerable research has been carried out to study the laser welding of magnesium alloys. However, the studies are mainly devoted to butt welding, and there has been limited information in the published literature concerning the bead-on-plate laser welding of AZ91D, even though bead-on-plate welding is required for the repair of cast AZ91D parts with surface defects. In the present investigation, surface cracking of the weld metal was observed when an AZ91D magnesium alloy was bead-on-plate welded using the laser welding method. This paper presents the experimental results and analyses to show that the cracking is “solidification cracking” initiated from the weld surface under high thermal stresses. This is in contrast to the “liquation cracking” observed in heat affected zones in tungsten inert gas welding of the same magnesium alloy. Laser power was found to be one of the main factors affecting the distance of the crack propagation. The higher laser power resulted in longer crack propagation distance into the weld metal. It is demonstrated that hot cracking could be avoided by lowering the laser power and welding speed.

show abstract

“…Therefore, it is necessary to develop a more environmental and effective anti-corrosion technologies to replace HA. Recently, micro-arc oxidation (MAO), as a novel surface treatment technique for Al, Mg, Ti, and their alloys [11][12][13], is attracting more interest in fabricating ceramic coatings to enhance the corrosion resistance, the wear resistance and the adhesion between the substrate and coating. There are fundamental differences between MAO and HA with 2 of 10 respect to the nature of electrolyte, the voltage ranges, and the coating formation mechanism [14].…”

Section: Introductionmentioning

confidence: 99%

A Comparative Study of Corrosion Behavior of Hard Anodized and Micro-Arc Oxidation Coatings on 7050 Aluminum Alloy

Shao

Jiang

et al. 2018

Metals

View full text Add to dashboard Cite

Two kinds of metal oxide coatings were fabricated on 7050 Al alloy by hard anodization (HA) and micro-arc oxidation (MAO) techniques. The microstructure, phase composition, and corrosion behavior of the two coatings were studied by scanning electron microscopy, X-ray diffraction, and corrosion tests, respectively. When compared with the HA coating, the MAO one was more effective to isolate the substrate from the corrosive environment. In addition, as confirmed by electrochemical tests, the MAO coating was of better corrosion resistance than the HA coating. Furthermore, it was revealed by neutral salt spray test that the MAO coating could protect substrate alloy over 1140 h, while the HA coating can only protect substrate alloy for 46 h due to the amorphous composition and through thickness defects (micro-pores and micro-cracks).

show abstract

Formation and Corrosion Resistance of Micro-Arc Oxidation Coating on Equal-Channel Angular Pressed AZ91D Mg Alloy

Cited by 7 publications

References 28 publications

Development of tantalum with highly hydrophilic surface and antimicrobial properties obtained by micro‐arc oxidation process

Development of tantalum with highly hydrophilic surface and antimicrobial properties obtained by micro‐arc oxidation process

Mechanisms of Cracking in Laser Welding of Magnesium Alloy AZ91D

A Comparative Study of Corrosion Behavior of Hard Anodized and Micro-Arc Oxidation Coatings on 7050 Aluminum Alloy

Contact Info

Product

Resources

About