Improvement of wear and corrosion resistance of AZ91 magnesium alloy by applying Ni–SiC nanocomposite coating via pulse electrodeposition

2013 ◽  
Vol 23 (10) ◽  
pp. 2914-2922 ◽  
Author(s):  
M. HAJIALI FINI ◽  
A. AMADEH
2005 ◽  
Vol 488-489 ◽  
pp. 701-704
Author(s):  
Hui Zhao ◽  
Zhong Han ◽  
Zhen Liu

This study is concerned with the effect of high energy ion beam irradiation on surface properties of AZ91 magnesium alloy. The study included a characterization of ion beam surface modification zone in terms of microstructure, and mechanical properties like nanohardness, wear, and corrosion resistance of the surface layer were studied in details. Nanohardness of the modification layer was improved about 2 times as that of the as-received AZ91. The corrosion resistance of the modified layer was significantly improved in NaCl solution because of refined grains. The wear resistance of the modification layer was also improved as compared to as-received AZ91.


Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 789 ◽  
Author(s):  
Farzad Soleymani ◽  
Rahmatollah Emadi ◽  
Sorour Sadeghzade ◽  
Fariborz Tavangarian

Magnesium alloys have received a great amount of attention regarding being used in biomedical applications; however, they show high degradability, poor bioactivity, and biocompatibility. To improve these properties, surface modification and various types of coatings have been applied. In this study, an anodized AZ91 alloy was coated with a polymer matrix composite made of polycaprolactone/chitosan (PCL/Ch) with different percentages of baghdadite to improve its resistance to corrosion, bioactivity, and biocompatibility. The effects of different percentages of baghdadite (0 wt %, 1 wt %, 3 wt %, and 5 wt %) on the surface microstructure, corrosion resistance, roughness, and wettability were evaluated. The results indicated that the applied nano-polymer-ceramic coating including 3 wt % baghdadite was hydrophobic, which consequently increased the corrosion resistance and decreased the corrosion current density of the anodized AZ91 alloy. Coating with 3 wt % baghdadite increased the roughness of AZ91 from 0.329 ± 0.02 to 7.026 ± 0.31 μm. After applying the polymer-ceramic coating on the surface of anodized AZ91, the corrosion products changed into calcium–phosphate compounds instead of Mg(OH)2, which is more stable in a physiological environment.


Coatings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 502 ◽  
Author(s):  
Sonia García-Rodríguez ◽  
Antonio Julio López ◽  
Victoria Bonache ◽  
Belén Torres ◽  
Joaquín Rams

This study shows that WC-12Co coatings with low porosity and high wear and corrosion resistance can be applied by high velocity oxygen-fuel (HVOF) on a low melting and highly flammable ZE41 magnesium alloy. This provides a novel and promising use of the high-energy thermal spraying technique on low temperature melting substrates. The spraying distance used was 300 mm, which is between two and three times the recommended distanced for HVOF coating with WC-12Co on steels. Despite this, the WC-12Co coatings obtained were homogeneous, crack-free, and dense. The coatings were very well adhered to the substrates and the spraying distance allowed avoiding any thermal affectation of the substrate. The thickness of the coatings was limited to 45 μm to avoid a big mass increase in the samples. The effect of the number of layers, the O2/H2 ratio and the gas transport flow in the coating was studied. The coatings reduced the wear rate of the substrate by 104 times, making them wear resistant. Electrochemical corrosion tests were conducted to study the corrosion protection of the coatings, showing that it is possible to protect the magnesium substrate for 96 h in contact with 3.5 wt.% NaCl aqueous solution.


2011 ◽  
Vol 194-196 ◽  
pp. 1221-1224 ◽  
Author(s):  
Zhong Jun Wang ◽  
Yang Xu ◽  
Jing Zhu

The microstructures and corrosion resistance of AZ91 and AZ91+0.5 wt.% erbium (Er) magnesium alloys were studied, respectively. The results show that the Er addition in scrap AZ91 magnesium alloy can improve the corrosion resistance, markedly. The discontinuous precipitation phase (DPP) for Mg17Al12was retarded and the amount of DPP was decreased by 41% due to the formation of Al8ErMn4phase during solidification. The amount of continuous precipitation phase (CPP) in grains was decreased by 8% because of the formation of Al7ErMn5phase during solidification.


2015 ◽  
Vol 1120-1121 ◽  
pp. 1078-1082 ◽  
Author(s):  
Yang Yang Lv ◽  
Ling Feng Zhang

Magnesium alloy as a green material in the 21st century, because of its excellent physical and mechanical properties of metallic materials as an ideal in the automotive industry, electronic industry and aviation, aerospace and other industries[1]. However, poor corrosion resistance of magnesium alloys become an important issue hinder application of magnesium alloys[2]. So magnesium alloy corrosion problems and the current status of research paper reviews several magnesium alloy protection methods at home and abroad, and also highlighted with our latest laser shock (LSP) study of AZ91 magnesium alloy at high strain rates of corrosion resistance results.


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