Dynamic material properties of refractory materials: Molybdenum

Conference · Tue Jan 01 04:00:00 EST 1991

OSTI ID:6012323

Furnish, M D; Chhabildas, L C

Recently, techniques have been developed to determine dynamic material properties of refractory metals at strain rates of 10{sup 5} to 10{sup 10} sec{sup {minus}1} and to stresses approaching 250 GPa. Similar techniques have been used to measure the dynamic properties of molybdenum; results are summarized in this paper. These experiments have allowed the determination of pressure and loading rate effects on the dynamic yield strength of molybdenum and its viscoelastic properties, as well as a determination of the Hugoniot, at relatively low stresses. Several combinations of loading and reloading and loading and unloading cycles have been employed, utilizing a compressed gas gun and VISAR diagnostics. Pressure ranges from 6.5 to 15 GPa were investigated with specimen thicknesses ranging from 1.5 to 13 mm. The Hugoniot is consistent with earlier observations at higher pressures. The Hugoniot elastic limit appears to decrease slightly with distance over the stress range reported in this study, although the decrease is of the same order as the uncertainties. Otherwise, waves are observed to be steady. Strengths at the HEL and the Hugoniot state, approximately 1.5 GPa, are within the range observed for lower strain rates of 10{sup {minus}3} sec{sup {minus}1} to 5{center dot}10{sup 3} sec{sup {minus}1}, consistent with a thermal activation slip model applicable across a wide range of strain rates. Strain rate behaves as approximately as the fourth power of stress, although it appears to decrease with propagation distance over the specimen thickness range used. 15 refs., 8 figs., 2 tabs.

• Research Organization: Sandia National Labs., Albuquerque, NM (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6012323
• Report Number(s): SAND-91-0679C; CONF-911003--21; ON: DE92003577
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
42 ENGINEERING
420500 -- Engineering-- Materials Testing
ALLOYS
CORUNDUM
ELEMENTS
INTERFEROMETERS
MEASURING INSTRUMENTS
MECHANICAL PROPERTIES
METALS
MINERALS
MOLYBDENUM
OXIDE MINERALS
REFRACTORY METALS
SAPPHIRE
STRAIN RATE
TRANSITION ELEMENTS
VELOCITY
VERY HIGH PRESSURE
YIELD STRENGTH