The effect of hot extrusion on the corrosion behavior of AZ91 alloy was studied by observing the change of grain size, the size and distribution of precipitated phase on the transverse and longitudinal sections before and after extrusion. The results show that the grain refinement of alloy was significant after extrusion, the grain size of the transverse section was uniform, that of the longitudinal section was different and the parallel streamline of shear stripes appeared. After extrusion, the decrease of the β-Mg17Al12 phase size reduces the relative potential difference between the second phase and the α-Mg matrix; the reduction of the transverse section was particularly significant. Grain refinement and precipitate size reduction after extrusion can improve the corrosion resistance of the AZ91 Mg alloy, which is the reason why the corrosion resistance of the transverse section was better than that of the longitudinal section.
LiuJZhangJLQuZB. Effects of rare earth Gd on corrosion resistance of AZ31 magnesium alloy. Mater Eng. 2018; 46 (6): 73–79.
2.
ChelliahNMSinghHRajR. Processing, microstructural evolution and strength properties of in-situ magnesium matrix composites containing nano-sized polymer derived SiC-NO particles. Mater Sci Eng A. 2017; 685: 429–438.
3.
ChangHWangJLZhengMY. Effect of equal channel angle deformation on microstructure and room temperature properties of SiCP/AZ91 composite cast by stirring casting. J Compos Mater. 2017; 34 (3): 611–618.
4.
FriedrichHSchumannS.Research for a ‘new age of magnesium’ in the automotive industry. J Mater Process Technol. 2001; 117 (3): 276–281.
5.
ChenZH.Deformed magnesium alloy. Beijing: Chemical Industry Press; 2005; 239–248.
6.
DobatkinSGalkinSEstrinY. Grain refinement, texture, and mechanical properties of a magnesium alloy after radial-shear rolling. J Alloys Compd. 2019; 774: 969–979.
7.
OnoNNowakRMiuraS.Effect of deformation temperature on Hall-Petch relationship registered for polycrystalline magnesium. Mater Lett. 2003; 58: 39–43.
8.
TanMLiuZMQuanGF.Effects of hot extrusion and heat treatment on mechanical properties and microstructures of AZ91 magnesium alloy. Energy Procedia. 2012; 16: 457–446.
9.
MasoudpanahSMMahmudiR.The microstructure, tensile, and shear deformation behavior of an AZ31 magnesium alloy after extrusion and equal channel angular pressing. Mater Des. 2010; 31: 3512–3517.
10.
ZhaoMCLiuMSongGL. Influence of the β-phase morphology on the corrosion of the Mg alloy AZ91. Corros Sci. 2008; 50: 1939–1953.
11.
LiaoHJZhouXFLiHL. Effect of aging time on corrosion behavior of As-forged AZ80 magnesium alloy. Trans Nonferrous Metals Soc China. 2015; 25: 3921–3927.
12.
BirbilisNRalstonKD, VirtanenS. Grain character influences on corrosion of ECAP pure magnesium. Corros Eng Sci Technol. 2010; 45 (3): 224–230.
13.
Hamu GBEliezerDWagnerL.The relation between severe plastic deformation microstructure and corrosion behavior of AZ31 magnesium alloy. J Alloys Compd. 2009; 468: 222–229.
14.
JinJBWangZXLiuXF. Effects of homogenization treatment on microstructure and mechanical properties of AZ91 magnesium alloy. J Metal. 2006; 42 (10): 1014–1018.
15.
SchmutzPFrankelGS.Characterization of AA2024-T3 by scanning kelvin probe force microscopy. J Electrochem Soc. 1998; 145 (7): 2285–2295.
16.
GuillauminVSchmutzPFrankelSG.Characterization of corrosion interfaces by the scanning kelvin probe force microscopy technique. J Electrochem Soc. 2001; 148 (5): B163–B173.
17.
HurleyMFEfawCMDavisPH. Volta potentials measured by scanning kelvin probe force microscopy as relevant to corrosion of magnesium alloys corrosion. 2015; 71 (2): 160–170.
18.
ZhangX.Study on microstructure, properties and corrosion mechanism of Mg-Re-based rare earth magnesium alloys [D]. Beijing: Beijing General Research Institute of Non-ferrous Metals; 2013.
19.
BobyASrinivasanAPillaiUTS. Mechanical characterization and corrosion behavior of newly designed Sn and Y added AZ91 alloy. Mater Des. 2015; 88: 871–879.
20.
SongGLAtrensA.Understanding magnesium corrosion a-framework for improved alloy performance. Adv Eng Mater. 2003; 5 (12): 837–857.
21.
SongGLAmandaLBStJohnDH.Corrosion resistance of aged die cast magnesium alloy. Mater Sci Eng A. 2004; 366: 74–86.
22.
SongGLAtrensADarguschM.Influence of microstructure on the corrosion of diecast AZ91D. Corros Sci. 1999; 41: 249–273.
23.
ZhangMHuYM.Plastic deformation of metals. Chongqing: Chongqing University Press; 1983.
24.
LiX.Study on corrosion resistance of AZ series magnesium alloy by Al2Sm intermetallic compound. Jiangxi: Nanchang University; 2018.
25.
AungNNZhouW.Effect of grain size and twins on corrosion behavior of AZ31B magnesium alloy. Corros Sci. 2010; 52: 589–594.
26.
ArgadeGRPanigrahiSKMishraRS.Effects of grain size on the corrosion resistance of wrought magnesium alloys containing neodymium. Corros Sci. 2012; 58: 145–151.
27.
HuangLYWangKSWangW. Effects of grain size and texture on stress corrosion cracking of friction Stir processed AZ80 magnesium alloy. Eng Fail Anal. 2018; 92: 92–404.
28.
DingYF.Effects of hot extrusion on microstructure and corrosion behavior of magnesium alloys. Inner Mongolia: Inner Mongolia University of Technology; 2019.
29.
ChenCLiuJChenMA. Corrosion behavior of magnesium alloy with extrusion aging state MB8 in brine. Chin J Nonferr Met. 2013; 6 (23): 1489–1495.
