c-axis compression twinning in an off-stoichiometric compound Ti3Al with the D019 structure

The characteristics of the c-axis compression twin in single crystals of a D019 compound Ti3Al with off-stoichiometric composition (Ti-36.5 at.%Al) have been studied by trace analysis and transmission electron microscopy. Deformation twinning is operative only at high temperatures above 1000 °C. All observed deformation twins are assigned to be of the type II and the twinning elements are determined as: K1:'{2¯121¯0¯3}', K2:{202¯1¯}, η1:〈51¯4¯6¯〉, η2:'〈1¯32¯2〉', s = 0.346.