The Role of Grain Size and Microstructure on the Shock Response of Metals (Summary Technical Report, Oct 2018-Sep 2020)
Abstract
For the first time a bulk nanocrystalline material, an alloy of nanocrystalline (NC) copper (Cu)-3at.%-tantalum (Ta), has been successfully shock-compressed from approximately 8 to 45 GPa using conventional and laser shock. Mechanical hardness and transmission electron microscopy results provide evidence that this material can resist high defect accumulation and damage as compared with other known materials reported in the open literature. This behavior is attributed to the stabilized grains and grain boundaries that act as stable sinks, analogous to a NC metal's known ability to absorb radiation damage, thereby providing a mechanism of resistance that neutralizes further deformation-induced defects. This represents an important material science discovery. Spall experiments revealed that through proper microstructural design and manipulation it is possible to increase the inherent spall strength of NC Cu-Ta alloys to a value that is 300% higher than conventional coarse-grain polycrystalline Cu. These results are startling as the spall strength of these NC Cu-Ta alloys is approaching the theoretical strength of Cu single crystals. These new results could pave the way for designing the next leap-ahead spall-resistant materials to enhance Soldier protection.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 2021
- Accession Number
- AD1131333
Entities
People
- Anit K. Giri
- B.C. Hornbuckle
- Cyril L. Williams
- John D. Clayton
- Kristopher A. Darling
- S. Dean
- S. Turnage
Organizations
- Sandia National Laboratories
- United States Army Research Laboratory