Electrical Response of a Bimetallic Junction to Shock Compression.
Abstract
The electrical response of a copper-constantan junction to shock compression has been studied over a pressure range from 145 kbars to 360 kbars. Four possible sources of anomalous response were found; electrical noise due to circuit closure at impact, shock demagnetization of a ferromagnetic material, high local temperature at the junction interface due to shock compression of a surface damage layer, and two-dimensional flow in the pressurized region due to pressure relief from the edges. Using a diffusion welded junction the emf measured is within 20% of the predicted emf based on normal thermocouple response to shock compression temperatures. In a geometry in which a guard ring was used to maintain the pressure behind the shock front, the observed voltage-time profile was a step with constant plateau. In a similar configuration where radial pressure relief was allowed behind the shock front, the initial step, which compares directly in amplitude to the above results, is followed by a marked positive ramping. This ramping was directly correlated with the two-dimensional flow due to radial pressure relief. The results indicate that any fundamental anomaly which exists for one-dimensional strain is less than 10-20% of the observed signals in the pressure range studied. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1978
- Accession Number
- ADA053693
Entities
People
- Douglas D. Bloomquist
- George E. Duvall
- Jerry J. Dick
Organizations
- Washington State University