Reversing the Grain Boundary Element Distribution of Al-Cu Alloy by Adding Boron to Synergistically Improve Mechanical Properties and Stress Corrosion Resistance

Abstract

Improving grain boundary segregation behavior can significantly enhance the performance of aluminum alloys. The addition of boron changes the distribution of Cu at grain boundaries from deficiency to enrichment, and this significant change synergistically improves the mechanical properties and stress corrosion resistance of Al-Cu alloys. Due to the occupation of vacancies by boron atoms, the migration rate of copper from grain boundaries to grain boundary precipitates is significantly inhibited. The segregation of Cu atoms at grain boundaries enhances the strength of the grain boundaries, while also hindering the electrochemical corrosion process. This study provides a new approach for the design of high-strength and corrosion-resistant aluminum alloys.

Keywords: Al-Cu alloy, Grain boundary segregation engineering, Boron