title: AFM study of the plastic deformation of polysynthetically-twinned (PST) TiAl crystals in soft orientation.
abstract: PST TiAl samples with a nominal composition of Ti52Al48 were deformed at room temperature with compression axis inclined to the lamellar interfaces by 45 degrees and one of the side surface normal directions set to be (112). The deformation structures on the free surfaces of the deformed samples were investigated using Atomic Force Microscope (AFM). It was found that in-plane shear (shear in planes parallel to lamellar interfaces) is the dominant deformation mode in all gamma domains and most of the deformation traces on the free surfaces are parallel to lamellar interfaces. Out-of-plane shear (shear in planes inclined to lamellar interfaces) also occurs but contributes much less to the macroscopic strain. This selective activation of deformation modes leads to a highly anisotropic deformation behavior in PST crystals with this orientation.
authors.affiliation: Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Yali
authors.initials: Y
authors.lastname: Chen
authors.forename: David P
authors.initials: DP
authors.lastname: Pope
mesh_terms: D000535:Aluminum / Q000737:chemistry*; D003460:Crystallization; D018625:Microscopy, Atomic Force; D010969:Plastics; D014025:Titanium / Q000737:chemistry*
chemical_list: D010969:Plastics; D000535:Aluminum; D014025:Titanium