Evolution of Mechanical Properties and Corrosion Resistance of Al-Zn-Mg Alloy with Different Numbers of Flame Rectification at 350°C
Yaqiang Wang
Intelligent Manufacturing Institute, HeNan Polytechnic, Zhengzhou,450000, China.
Xin Liu
School of Mechanical Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450045, China.
Dan Guo
School of Materials Science and Engineering, Dalian University of Technology, Dalian, 116024, China.
Shuai Li *
School of Mechanical Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450045, China.
*Author to whom correspondence should be addressed.
Abstract
This paper investigated the microstructure, tensile properties, intergranular corrosion resistance and exfoliation corrosion resistance of Al-4.5Zn-1.5Mg (wt.%) alloy after undergoing different numbers of flame rectification at 350°C. The results showed that in the flame correction area, the mechanical properties of Al-4.5Zn-1.5Mg(wt.%) alloy with two times of flame correction is the best. The maximum tensile strength and elongation of Al-4.5Zn-1.5Mg(wt.%) alloy inside the region of flame correction are 387MPa and 26.37% respectively. The flame rectification accelerated the corrosion susceptibility of Al-4.5Zn-1.5Mg (wt.%) alloy. The maximum intergranular corrosion depth is detected with the value of 105μm after one time of FR. The corrosion property of Al-4.5Zn-1.5Mg(wt.%) alloy is mainly related to the formation of galvanic couple. The uneven distribution of the second phase particles of Al-4.5Zn-1.5Mg(wt.%) alloys results in different corrosion potentials at grain boundaries and within grains, leading to galvanic corrosion.
Keywords: Al-Zn-Mg alloy, flame rectification, microstructure, mechanical properties, corrosion properties