EFFECT OF INTERGRANULAR SEGREGATION OF Mg ON THE EXFOLIATIVE CORROSION IN Al-Mg ALLOYS

LIN ZHAOQI; JIANG JIAREN; ZHAO GANG; RU HUONGQIANG

doi:doi:10.1051/jphyscol:1990190

Numéro		J. Phys. Colloques Volume 51, Numéro C1, Janvier 1990 Proceeding of the International Congress Intergranular and Interphase Boundaries in materials


Page(s)		C1-575 - C1-580
DOI		https://doi.org/10.1051/jphyscol:1990190

J. Phys. Colloques 51, C1-575-C1-580 (1990)
DOI: 10.1051/jphyscol:1990190

EFFECT OF INTERGRANULAR SEGREGATION OF Mg ON THE EXFOLIATIVE CORROSION IN Al-Mg ALLOYS

LIN ZHAOQI, JIANG JIAREN, ZHAO GANG et RU HUONGQIANG

Department of Material Science and Engineering, Northeast University of Technology, Shenyang, P.R. China

Abstract
The effect of cooling rate, CR, after annealing and precipitation temperature, T_p, on the segregation of magnesium. M_g(GB), to grain boundary, the distribution of Mg-concentration, the microstructure, and the exfoliative corrosion, EC, in Al-Mg alloys with 3-7wt. % Mg has been studied by means of EDS, STEM, microscopy and ASSET immersion test. The results obtained show that Mg(GB) in Al-3wt. % Mg alloy is not influenced greatly by CR and T_p, and it shows a highest EC stability. Otherwise the Mg(GB) in Al-5wt. % Mg and Al-7wt. % Mg alloy are obviously influenced by CR and T_p, and they have enough EC stabilities only when both the CR is lowered to a critical rate and the T_p is risen to a critical temperature, Tcp, the Mg(GB) will lower to some critical values, and the continuous grain boundary film of β-phase disappear.