The Slip and Deformation Twinning for Non - stoichiometric Ti3Al Alloys
이종욱 , 이광로 , 김일봉 , 박영구 , 화전수치 Jong Wook Lee , Kwang Ro Lee , Il Bong Kim , Young Koo Park , Shuji Hanada
Abstract
Compression tests for a single crystalline and polycrystalline Ti₃Al alloys of the hexagonally ordered DO_(19) structure deformed in compression were carried out to determine a temperature range in which deformation twinning is induced. Deformation twinning does not occur in a single crystalline Ti₃Al alloys. Prism plane slips are activated when single crystalline Ti₃Al alloys are compressed in the vicinity of the a axis. On the other hand, pyramidal and basal plane slips are activated when single crystalline Ti₃Al alloys are compressed in the vicinity of the c axis. In a polycrystalline Ti₃Al alloys, deformation twinning does occur in the temperature range of 1073K to 1373K only in Ti-34㏖%Al alloy. Dominant deformation twinning system is identified as [101 ̄1] (1012 ̄) in the temperature range of 1073K to 1373K. The volume fraction of deformation twins increases with increasing temperature in the temperature range of 1073K to 1273K. With further increasing temperature, however, the volume fraction of deformation twins decreases. The volume fraction of deformation twins increases with increasing total strain at 1173K and 1273K. Non-a dislocations and APBs in Ti-34㏖%Al alloy are visible in the temperature range induced deformation twinning.