Effect of Mg Additions and Thermal Treatment on Corrosion Properties of Al-Li-Cu-Base Alloys

Abstract

An investigation on the corrosion and electrochemical behavior of experimental and industrial semifinished items of Al–Li–Cu–base alloys offers possibilities of increasing the corrosion resistance of aluminum–lithium alloys by alloying and an nontraditional thermal treatment. Magnesium added in a concentration of no more than 0.4% leads to a improvement of the corrosion and mechanical characteristics of the alloy, whereas increasing its concentration up to 1.0% deteriorates all the corrosion characteristics. An investigation of the effect of the cathodic additions of Zr, Mn, and Mn + Cr shows that the corrosion properties are nonchanged by substitution of Mn or Mn + Cr for Zr. The resistance to general corrosion, exfoliation corrosion, and corrosion cracking is enhanced by a nontraditional artificial aging.