Positron lifetime measurements as a non-destructive technique to monitor fatigue damage. Final report, January 1, 1971--June 30, 1978. [Electrons, vacancies]

Technical Report · Thu Jun 01 04:00:00 EDT 1978

DOI:https://doi.org/10.2172/6533956· OSTI ID:6533956

Byrne, J G

Positron studies were applied successfully to cyclic fatigue in steel and copper and have shown a capability to nondestructively detect fatigue softening and fatigue hardening. In the case of elastic high cycle fatigue in initially soft steel the fatigue hardening is identified with point defects. For cyclic plastic range, high cycle fatigue cyclic hardening and softening are correlated with changes in dislocation substructure. Positron measurements during the pulse annealing of copper single crystals following electron irradiation at 77/sup 0/K have revealed the formation of multi-vacancy complexes which constitute the precursors of radiation induced voids. Positron studies have been applied to hydrogen embrittlement in 4340 steel and more recently in nickel. The technique can non-destructively detect hydrogen embrittlement and gage its extent. U.S. Patent No. 4064438 was issued on this basis.

• Research Organization: Utah Univ., Salt Lake City (USA). Dept. of Materials Science and Engineering
• OSTI ID: 6533956
• Report Number(s): COO-2128-13
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104 -- Metals & Alloys-- Physical Properties
360105* -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
ANNEALING
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
COPPER
CORRELATIONS
CRYOGENIC FLUIDS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
CRYSTALS
DISLOCATIONS
ELECTRONS
ELEMENTARY PARTICLES
ELEMENTS
EMBRITTLEMENT
FATIGUE
FERMIONS
FLUIDS
HEAT TREATMENTS
HYDROGEN
IRON ALLOYS
IRON BASE ALLOYS
LEPTONS
LIFETIME
LINE DEFECTS
MECHANICAL PROPERTIES
METALS
MONOCRYSTALS
NICKEL
NONMETALS
PHYSICAL RADIATION EFFECTS
PLASTICITY
POINT DEFECTS
POSITRONS
RADIATION EFFECTS
STEELS
TRANSITION ELEMENTS
VACANCIES