Effects of Yttrium Addition on Plastic Deformation of Rolled Magnesium

Abstract

Tensile tests were applied to rolled MgY alloy sheets with three at% of yttrium-Mg0.54 at% Y, Mg0.9 at% Y, and Mg1.21 at% Y-to investigate effects of yttrium addition on activities of basal slip and non-basal slip systems so as to clarify the relationship between tensile properties and activities of slip systems. 0.2% proof stress of MgY alloys increased with increasing yttrium content ranging from 0.5 to 1.2 at%. Ductility increased with increasing yttrium content until 0.9 at% but decreased when 1.2 at% was added. Frequencies of basal and non-basal slips increased by yttrium addition. The frequency of f10 11gh11 23i first order pyramidal slip (FPCS) increased with increasing yttrium content until 0.9 at% and decreased when 1.2 at% was added. With increasing yttrium content, the frequency of f11 22gh11 23i second order pyramidal slip (SPCS) decreased, while that of f10 10gh11 20i prismatic slip (PS) increased. The highest total frequency of non-basal slips was observed in Mg 0.9Y, showing the highest ductility. Enhancement of ductility on magnesium was caused by activation of both basal and non-basal slips through yttrium addition.