Estimation of Active Slip System with Crack Propagation in Pure Titanium Film with Rolling Texture （Based on Crystal Orientation Measurement by EBSD Method）

Abstract

Pure titanium films with rolling texture were fatigued. In order to discuss correlation between fatigue crack propagation and active slip systems, crystal orientation around the fatigue crack was measured. The crystallographic information was analyzed using the Electron Back-scatter Diffraction (EBSD) system and a misorientation vector was estimated as the axis of misorientation angle. As a result, fatigue cracks propagated faster in the specimen loaded to the rolling direction than in that loaded to the transverse direction. Using the misorienation vector, the active slip system with crack propagation was estimated. It is found that the fatigue crack propagated by two prismatic slip systems in the specimen loaded to the rolling direction. On the other hand, the fatigue crack seems to propagate by one basal slip system in the specimen loaded to the transverse direction. The basal slip hardly operates because the slip is limited in one plane and the fatigue crack propagation is decelerated in the specimen loaded to the transverse direction.