Rise-time measurements of shock transitions in aluminum, copper, and steel

Journal Article · Sun Apr 01 04:00:00 EST 1979 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.326236· OSTI ID:6341289

Chhabildas, L C; Asay, J R

Time-resolved measurements of shock-wave rise times have been accomplished for aluminum, copper, and steel to stress levels of 41, 96, and 139 GPa, respectively, using velocity-interferometer techniques. To within the time resolution of the technique, the shock transition is found to occur within 3 ns in all materials. Based on this upper limit for the transition time, limiting viscosity coefficients of 1000, 3000, and 4000 P are obtained for 6061-T6 aluminum, OFHC copper, and 4340 steel, respectively, at strain rates above 10/sup 8/ s/sup -1/. It is found that the effective viscosity can be expressed as parameters in a Maxwellian relation for an elastic-plastic solid, in which the viscosity is related to an effective relaxation time. It is also shown that viscosity is inversely proportional to mobile-dislocation density, which implies that the density of mobile dislocations obtained during shock compression in these materials is well over 10/sup 9//cm/sup 2/.

• Research Organization: Sandia Laboratories, Albuquerque, New Mexico 87185
• OSTI ID: 6341289
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 50:4; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
ALUMINIUM
COMPRESSION
COPPER
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DISLOCATIONS
ELASTICITY
ELEMENTS
IMPACT SHOCK
IRON ALLOYS
IRON BASE ALLOYS
LINE DEFECTS
MECHANICAL PROPERTIES
METALS
PLASTICITY
SHOCK WAVES
STEELS
STRAINS
STRESSES
TENSILE PROPERTIES
TRANSITION ELEMENTS
VERY HIGH PRESSURE
VISCOSITY
WAVE PROPAGATION