ISSN:
1013-9826
Quelle:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Thema:
Maschinenbau
Notizen:
Cored wires and high velocity arc spraying (HVAS) technologies have been applied toproduce Zn-Al-Mg-RE coating on A3 steels. The durability of coating in terms of corrosionresistance is the focus of this paper. The detailed degradation mechanism has been investigated usingelectrochemical-monitoring techniques supported by precise pre-test and post-test microscopicalexamination using Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD).Zn-Al-Mg-RE coating shows a typical aspect of layered heterogeneous structure, the existing ofZnAl2O4 and MgAl2O4 implies the good anti-corrosion feature. The polarization curves showed thatZn-Al-Mg-RE coating exhibits passive behavior at 0.5h and 16h immersion, but at 600h, it begins todissolute. In contrast, the anti-corrosion performance isn’t cut down. The corrosion potential movesto the noble direction step by step, along with the current density drops gradually. After corrosion, ithas been observed that the coating surface is jointed by flaky lamellar products and dense withoutobvious defects and pores. It is postulated that with the addition of RE, the porosity of the coating isreduced, meanwhile, the stability of the products layer can reinforce the self-sealing effect of thecoating distinctively
Materialart:
Digitale Medien
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/57/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.373-374.64.pdf
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