| CHENG Qing-peng,HUANG Xiu-ling,ZHANG Fan.Recent Progress on Corrosion and Protection of Ultrafine-grained Magnesium Alloys[J],52(4):112-123 |
| Recent Progress on Corrosion and Protection of Ultrafine-grained Magnesium Alloys |
| |
| View Full Text View/Add Comment Download reader |
| DOI：10.16490/j.cnki.issn.1001-3660.2023.04.008 |
| KeyWord:magnesium alloys ultrafine-grained severe plastic deformation surface modification corrosion resistance corrosion and protection |
| Author | Institution |
| CHENG Qing-peng |
College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing , China |
| HUANG Xiu-ling |
College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing , China |
| ZHANG Fan |
School of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai , China |
|
| Hits: |
| Download times: |
| Abstract: |
| Magnesium and its alloys are known as the green engineering material in the 21st century, but their low mechanical properties and pool corrosion resistance limit their wide engineering application and industrialization. Severe plastic deformation technology can simultaneously improve the strength and toughness of magnesium alloys through ultrafine microstructure, but the corrosion resistance of ultrafine-grained magnesium alloys varies with the changes of their own composition and microstructure, grain size, corrosion medium and preparation process. This paper summarized the recent research progresses on corrosion and protection of ultrafine-grained magnesium alloys after severe plastic deformation. In the first section, summary of the corrosion behavior of magnesium alloys processed by different severe plastic deformation techniques was introduced. Starting with the commonly used equal channel angular pressing and high-pressure torsion, the effects of chemical composition and strain induced microstructural evolution during severe plastic deformation on the corrosion behavior were clarified. It was found that the initial composition of magnesium alloys may play a dominate role in the change of corrosion resistance of samples after severe plastic deformation. For pure magnesium and magnesium alloys containing passivating elements such as aluminum or rare earth elements (AZ series, AM series, ZE series, WE series, etc.), most processing would promote the formation of a denser protective film, which could improve the corrosion resistance of magnesium alloys. However, for Mg-Zn based alloys without such elements like ZK60 and Mg-Zn-Ca alloys, due to the formation of more micro galvanic couples, the refinement and distribution of second phase particles caused by equal channel angular pressing or high-pressure torsion would accelerate the corrosion of magnesium alloys. However, multiaxial isothermal forging could improve the corrosion resistance of such alloys, which deserved more attention. In the case of similar composition, the effects of microstructure uniformity or the change of second phase might be greater than that of grain size and texture evolution. Fine and uniform distribution of secondary phases after processing might be beneficial to the corrosion resistance of magnesium alloys. Meanwhile, the strain induced non-basal textures were found harmful to the corrosion resistance according to several literature. For magnesium alloys processed by surface severe plastic deformation techniques such as severe shot peening, unlike the common severe plastic deformation, surface toughness became an important factor which greatly affected the corrosion behavior. In the second section, some potential methods to further increase the corrosion resistance of processed magnesium alloys were also introduced. Processing proper heat treatment or surface modification of processed magnesium alloys were effective means to further improve their corrosion resistance. Heat treatment could further regulate the microstructures after processing, making them with more uniformly distributed fine secondary particles and with less residual stress. Compared with the coarse-grained substrate, better corrosion resistance was often found for the coating on ultrafine-grained substrate after surface modification via micro-arc oxidation or hydrothermal treatment, which was worthy of more research attention. Finally, a conclusion was made in consideration of future work. The combination of proper severe plastic deformation techniques and post modifications has the great potential to produce magnesium alloys with both high mechanical properties and good corrosion resistance. As the currently used corrosion mediums and methods for corrosion tests are strongly depended on different authors, especially for the simulated body fluid, at least five or six different kinds of composition were found in the literature, making it difficult to compare different literature. Therefore, it is urgent to set a standard for the whole magnesium section. |
| Close |
|
|
|