VIRTUAL

 

Thursday, March 11th   2021

3:45 – 4:45 p.m.

WEBEX

 

Speaker:  Brian J. Jensen

 

Shock and Detonation Physics (M-9)

Los Alamos National Laboratory

 

 

“Examining the shock response of metals using

X-ray diffraction and optical pyrometry diagnostics”

 

 

 

Abstract: 

Shock wave experiments have proven useful for decades for examining material response at high pressures, and providing equation-of-state and other relevant information for numerous phenomena including phase transitions, material strength, and kinetics. Traditional diagnostic, such as stress gauges and interface velocimetry (e.g. PDV and VISAR), provide the shock wave profile at an interface, shock velocity, stress, and sound speeds which are all needed to understand the mechanical state of the material at pressure.  Although there has been much success in relating the shock-wave profile to the material response, these traditional diagnostics provide indirect information about the microscopic level mechanisms that are active, and essentially no information about temperature or microstructure.   More advanced experiments and diagnostics are needed to fully characterize the state of the material including X-ray diffraction (microstructure) and optical pyrometry (temperature).  For many years, the successful application of these diagnostics has remained elusive due in part to the short time scales (< 1 microsecond) associated with shock wave or high strain rate experiments.   Recent developments within the last decade have led to significant progress in in coupling these diagnostics to shock wave experiments.  In this talk, the use and limitation of traditional diagnostics will be presented to motivate the development of X-ray diffraction and optical pyrometry followed by an example of their application to study multiphase properties of metals.