Dendritic structure formation of magnesium alloys for the manipulation of corrosion properties: Part 2 – corrosion

Author(s):  
Piotr Łakoma ◽  
André Ditze ◽  
Christiane Scharf
2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110294
Author(s):  
Khaled Abd El-Aziz ◽  
Emad M Ahmed ◽  
Abdulaziz H Alghtani ◽  
Bassem F Felemban ◽  
Hafiz T Ali ◽  
...  

Aluminum alloys are the most essential part of all shaped castings manufactured, mainly in the automotive, food industry, and structural applications. There is little consensus as to the precise relationship between grain size after grain refinement and corrosion resistance; conflicting conclusions have been published showing that reduced grain size can decrease or increase corrosion resistance. The effect of Al–5Ti–1B grain refiner (GR alloy) with different percentages on the mechanical properties and corrosion behavior of Aluminum-magnesium-silicon alloy (Al–Mg–Si) was studied. The average grain size is determined according to the E112ASTM standard. The compressive test specimens were made as per ASTM: E8/E8M-16 standard to get their compressive properties. The bulk hardness using Vickers hardness testing machine at a load of 50 g. Electrochemical corrosion tests were carried out in 3.5 % NaCl solution using Autolab Potentiostat/Galvanostat (PGSTAT 30).The grain size of the Al–Mg–Si alloy was reduced from 82 to 46 µm by the addition of GR alloy. The morphology of α-Al dendrites changes from coarse dendritic structure to fine equiaxed grains due to the addition of GR alloy and segregation of Ti, which controls the growth of primary α-Al. In addition, the mechanical properties of the Al–Mg–Si alloy were improved by GR alloy addition. GR alloy addition to Al–Mg–Si alloy produced fine-grained structure and better hardness and compressive strength. The addition of GR alloy did not reveal any marked improvements in the corrosion properties of Al–Mg–Si alloy.


2015 ◽  
Vol 60 (2) ◽  
pp. 1031-1035 ◽  
Author(s):  
J. Smolik ◽  
A. Mazurkiewicz ◽  
J. Kacprzyńska-Gołacka ◽  
M. Rydzewski ◽  
M. Szota ◽  
...  

Abstract Magnesium alloys have very interesting physical properties which make them ‘materials of the future’ for tools and machine components in many industry areas. However, very low corrosion and tribological resistance of magnesium alloys hampers the implementation of this material in the industry. One of the methods to improve the properties of magnesium alloys is the application of the solutions of surface engineering like hybrid technologies. In this paper, the authors compare the tribological and corrosion properties of two types of “MgAlitermetalic / PVD coating” composite layers obtained by two different hybrid surface treatment technologies. In the first configuration, the “MgAlitermetalic / PVD coating” composite layer was obtained by multisource hybrid surface treatment technology combining magnetron sputtering (MS), arc evaporation (AE) and vacuum heating methods. The second type of a composite layer was prepared using a hybrid technology combined with a diffusion treatment process in Al-powder and the electron beam evaporation (EB) method. The authors conclude, that even though the application of „MgAlitermetalic / PVD coating” composite layers can be an effective solution to increase the abrasive wear resistance of magnesium alloys, it is not a good solution to increase its corrosion resistance.


2019 ◽  
Vol 6 (11) ◽  
pp. 1165f9 ◽  
Author(s):  
Yasin Subasi ◽  
Yunus Turen ◽  
Huseyin Zengin ◽  
Hayrettin Ahlatci ◽  
Yavuz Sun

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 391 ◽  
Author(s):  
Jan Bohlen ◽  
Sebastian Meyer ◽  
Björn Wiese ◽  
Bérengère J. C. Luthringer-Feyerabend ◽  
Regine Willumeit-Römer ◽  
...  

Magnesium alloys attract attention as degradable implant materials due to their adjustable corrosion properties and biocompatibility. In the last few decades, especially wrought magnesium alloys with enhanced mechanical properties have been developed, with the main aim of increasing ductility and formability. Alloying and processing studies allowed demonstrating the relationship between the processing and the microstructure development for many new magnesium alloys. Based on this experience, magnesium alloy compositions need adjustment to elements improving mechanical properties while being suitable for biomaterial applications. In this work, magnesium alloys from two Mg-Zn series with Ce (ZE) or Ca (ZX) as additional elements and a series of alloys with Ag and Ca (QX) as alloying elements are suggested. The microstructure development was studied after the extrusion of round bars with varied processing parameters and was related to the mechanical properties and the degradation behavior of the alloys. Grain refinement and texture weakening mechanisms could be improved based on the alloy composition for enhancing the mechanical properties. Degradation rates largely depended on the nature of second phase particles rather than on the grain size, but remained suitable for biological applications. Furthermore, all alloy compositions exhibited promising cytocompatibility.


2016 ◽  
Vol 258 ◽  
pp. 530-533
Author(s):  
Martin Klein ◽  
Patrick Buhr ◽  
Frank Walther

Magnesium alloys offer high potential for lightweight constructions, e.g. in automotive applications. However, their application range is limited due to their low corrosion resistance. In the present study, the influence of corrosion on the microstructure and the depending mechanical properties under cyclic loading were characterized for the creep-resistant DieMag422 (Mg4Al2Ba-2Ca) and AE42 magnesium alloys. In this context, fatigue properties in distilled water and sodium chloride solutions were assessed in constant amplitude tests. The results were correlated with corrosion properties of the alloys, which were evaluated by immersion tests. Corrosion-and deformation-induced microstructural changes were observed by light and scanning electron microscopy (SEM), yielding a structure-property-relationship for a comprehensive understanding of mechanical and corrosive deterioration mechanisms.


2020 ◽  
Vol 1000 ◽  
pp. 115-122
Author(s):  
Nono Darsono ◽  
Murni Handayani ◽  
Franciska Pramuji Lestari ◽  
Aprilia Erryani ◽  
I Nyoman Gede Putrayasa ◽  
...  

Magnesium Alloys have the potential to be applied in the various fields of applications including biomaterials. Magnesium Alloys are an interesting alloy due to its high strength to density ratio. They have been proposed as a biodegradable implant material due to its friendly effect to human body compared to another alloy. Besides its good biodegradable properties, it has a disadvantage of low hardness and corrosion properties. In order to overcome this, it has been combined with other metals such as Zinc (Zn) or Copper (Cu). To increase mechanical properties, we used Carbon Nanotubes (CNT) as reinforcement. Magnesium-Zinc (Mg-xZn) CNTs composites with several compositions was prepared by using powder metallurgy and sintered in the presence of flowing Argon (Ar) gas in tube furnace. Mg-Zn Alloy with the composition of 4% and 6% of Zn and the variation of CNTs at 0.1%, 0.3 %, and 0.5% was also prepared. Hardness testing by using microvickers showed that CNTs can increase the alloy hardness which the maximum hardness is 53.6 HV. The corrosion rates as low as 175.5 mpy exhibited for the Mg-Alloy with the composition of Mg-4-Zn with 0.1 wt.% of CNTs


2004 ◽  
Vol 40 (5) ◽  
pp. 585-590 ◽  
Author(s):  
W. Dietzel ◽  
M. Klapkiv ◽  
H. Nykyforchyn ◽  
V. Posuvailo ◽  
C. Blawert

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