Energetics of dislocation relaxation associated with cleavage in Cd-doped zinc crystals as probed by synchrotron topography

Conference · Wed Jan 01 00:00:00 EST 1986

OSTI ID:5542381

Schmitz, H A; Bilello, J C; Rek, Z

An almost ten-fold increase in the cleavage energy of 0.1% Cd-doped zinc crystals has been previously reported in the literature and attributed to an increase in the intrinsic surface energy. The energetics of the cleavage process as a function of dopant concentration over the range 0.01, 0.03, 0.06 and 0.13% Cd has been systematically measured and correlated with the observed dislocation microstructure induced by crack initiation and growth. The dislocation relaxation zones were determined by nondestructive observations using synchrotron radiation topography. Since the primary cleavage and slip systems are co-planar, previous workers have ignored plastic relaxation and assumed fracture had to proceed in a purely brittle fashion. Synchrotron topography results indicated extensive plastic relaxation at the crack tip and also downstream during crack propagation. Based on these observations a modified Griffith analysis could be used to determine the relative contributions to the cleavage energy due to the intrinsic surface and dislocation relaxation processes. It was concluded that the latter process is the dominant factor in controlling the fracture toughness of these alloys.

• Research Organization: State Univ. of New York, Stony Brook (USA). Dept. of Materials Science and Engineering; Stanford Univ., CA (USA). Stanford Synchrotron Radiation Lab.
• DOE Contract Number: FG02-84ER45098
• OSTI ID: 5542381
• Report Number(s): DOE/ER/45098-11; CONF-860809-1; ON: DE86002968
• Resource Relation: Conference: International conference on low-energy dislocation structures, Charlottesville, VA, USA, 10 Aug 1986
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ZINC
FRACTURE PROPERTIES
CADMIUM ADDITIONS
CRACK PROPAGATION
CRYSTALS
DISLOCATIONS
DOPED MATERIALS
RELAXATION
SYNCHROTRON RADIATION
TOPOGRAPHY
X RADIATION
ALLOYS
BREMSSTRAHLUNG
CADMIUM ALLOYS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
ELECTROMAGNETIC RADIATION
ELEMENTS
IONIZING RADIATIONS
LINE DEFECTS
MATERIALS
MECHANICAL PROPERTIES
METALS
RADIATIONS
360103* - Metals & Alloys- Mechanical Properties