Effect of Solution Treatment on Microstructure and Corrosion Resistance of AZ91HP Magnesium Alloy

4th Annual International Workshop on Materials Science and Engineering

Guo, Lingling^1 ; Zhang, Jumei^1 ; Zhang, Yang^1 ; Cai, Hui^1

School of Materials Science and Engineering, Xi'An University of Science and Technology, Xi'an

710054, China^1

关键词: 3.5% nacl solutions;    Analytical method;    As cast alloy;    Composite solids;    Electrochemical polarization;    Mg17Al12 phase;    Rapid cooling;    Solution treatments;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/381/1/012005/pdf
DOI  :  10.1088/1757-899X/381/1/012005

来源: IOP

【 摘 要 】

The microstructure and corrosion resistance of AZ91HP magnesium alloy after different solution treatment were studied emphatically by means of optical microscopy (OM), electrochemical polarization curve and 3.5%NaCl solution immersion and other analytical methods. The results show that the coarse β-Mg17Al12 phase with continuous reticular distribution dissolves at the grain boundary after the as-cast AZ91HP magnesium alloy through solution treatment at 415°C for 24h with air-cooling, the Al element diffuses more adequate in the α-Mg matrix and the content of β-Mg17Al12 is much more. When cooling in water, because of the rapid cooling rate, the amount of Al elements in the matrix of α-Mg is less, and the formation of β-Mg17Al12 is less; the grain size of the magnesium alloy by composite solution treated is significantly reduced. After composite solid solution treatment at 410°C, a small amount of undissolved β phase still exists at the grain boundaries of α-Mg. When the temperature of the composite solution rose to 415°C, the phase of β-Mg17Al12 at the grain boundary was completely dissolved; the corrosion resistance of solid solution AZ91HP magnesium alloy is better than that of as-cast alloy.