DEFORMATION TWINNING IN AN AGE-HARDENED CU-4 WT PERCENT TI ALLOY

Deformation twinning in a Cu-4% Ti alloy was studied on polycrystalline specimens age-hardened by the formation of a modulated structure. The twinning stress in the hardest specimen was found to decrease with raising the deformation temperature from -40°C to 250°C. Thin foil observations revealed that the number of twins increased as the deformation increased and in several cases two sets of twins intersected each other, creating a secondary twin inside the intersected twin. A dislocation model for twinning is proposed to interpret the temperature dependence of the twinning stress observed in the present alloy. Behaviors of intersection between twin and twin or slip dislocations are discussed in terms of the dislocation reactions at the twin boundaries. © 1969, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.