Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Subgrain geometrically necessary dislocation density mapping in spalled Ta in three dimensions

Journal Article · · Acta Materialia
Here, in this work, the intragranular distributions of the densities of geometrically necessary dislocations (GNDs) generated in a polycrystalline tantalum (Ta) sample loaded in shock compression to spall are investigated. The sample studied is a highly resolved three-dimensional (3D) map of the orientations, grain boundary morphology, and voids across a 0.276mm3 (with sample dimensions of 688.5µm x 669µm x 600µm) region of the microstructure about the spall plane obtained by TriBeam tomography. We present a formulation for calculating the crystallographic screw and edge character GND densities at a material point within body centered cubic (BCC) crystals when provided any number of potential slip systems or modes. Combining the 3D characterization, GND formulation, and a sample containing ≈ 6000 grains, we sought statistically relevant correlations between GND density per grain with grain size, grain orientation, void formation, and proximity from the spall plane. We show that GND density per grain increases with decreasing distance from the spall plane. Most grains had heterogeneously distributed GND densities but were free of any detectable voids, at least within the ≈ 1.5µm resolution of the characterization technique. It is found that the GND density for most grains is insensitive to grain size and grain orientation. Only the fraction of grains with the highest GND densities tended to have a [001] parallel to shock-direction orientation. Intragranular 3D maps of GNDs reveals that grains that contain voids have high GND density concentrations in the intragranular region immediately surrounding the void. The local intragranular GND mapping also showed voids that are connected to grain boundaries preferred to grow into the grain with the larger size, regardless of orientation.
Research Organization:
Texas A & M Univ., College Station, TX (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA)
Grant/Contract Number:
NA0003857
OSTI ID:
2417899
Alternate ID(s):
OSTI ID: 1961292
Journal Information:
Acta Materialia, Journal Name: Acta Materialia Journal Issue: C Vol. 244; ISSN 1359-6454
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English

References (66)

Slip Geometry of Tantalum and Tantalum Alloys journal December 1975
The absence of steady-state flow during large strain plastic deformation of some Fcc metals at low and intermediate temperatures journal December 1988
Microstructural evolution in nickel during rolling from intermediate to large strains journal September 1993
Spall fracture: methodological aspects, mechanisms and governing factors journal January 2010
Boundary characterization using 3D mapping of geometrically necessary dislocations in AM Ta microstructure journal March 2022
Grain Boundary Responses to Heterogeneous Deformation in Tantalum Polycrystals journal November 2013
Recent Developments in Femtosecond Laser-Enabled TriBeam Systems journal November 2021
A Concise Note on Deformation Twinning and Spall Failure in Magnesium at the Extremes journal August 2020
Some geometrical relations in dislocated crystals journal March 1953
Dynamic fracture (spalling) of metals journal January 1983
The physics of plastic deformation journal January 1987
Deformation structures in lightly rolled pure aluminium journal July 1989
Strain gradient plasticity: Theory and experiment journal February 1994
Indentation size effects in crystalline materials: A law for strain gradient plasticity journal March 1998
Strain gradient crystal plasticity: size-dependentdeformation of bicrystals journal February 1999
Mechanism-based strain gradient plasticity? I. Theory journal April 1999
Mechanism-based strain gradient plasticity—II. Analysis journal January 2000
Strain Gradient Plasticity book January 1997
Microstructure and strength of nickel at large strains journal June 2000
Laser-induced shock compression of monocrystalline copper: characterization and analysis journal March 2003
Crystallographic aspects of geometrically-necessary and statistically-stored dislocation density journal March 1999
The Orientation of Dislocation Walls in Rolled Copper Relative to the Crystallographic Co-Ordinate System journal December 1997
Grain Orientation Effect on Microstructure in Tensile Strained Copper journal May 1998
Void growth by dislocation emission journal April 2004
Void growth in metals: Atomistic calculations journal September 2008
Orientation dependence of shock-induced twinning and substructures in a copper bicrystal journal January 2010
Plastic deformation in nanoindentation of tantalum: A new mechanism for prismatic loop formation journal October 2014
Assessment of geometrically necessary dislocation levels derived by 3D EBSD journal October 2015
Intragranular void formation in shock-spalled tantalum: Mechanisms and governing factors journal April 2018
Spall strength dependence on grain size and strain rate in tantalum journal October 2018
Dislocation density distribution at slip band-grain boundary intersections journal January 2020
Investigating active slip planes in tantalum under compressive load: Crystal plasticity and slip trace analyses of single crystals journal February 2020
Multimodal 3D characterization of voids in shock-loaded tantalum: Implications for ductile spallation mechanisms journal August 2021
Towards the ultimate strength of iron: spalling through laser shock journal August 2021
An experimental investigation on cyclic plastic deformation and substructures of polycrystalline copper journal November 2005
Predicting the Hall–Petch effect in fcc metals using non-local crystal plasticity journal July 2008
Texture simulation of a severely cold rolled low carbon steel using polycrystal modeling journal October 2018
A multiscale investigation into the effect of grain size on void evolution and ductile fracture: Experiments and crystal plasticity modeling journal February 2020
Local micro-mechanical stress conditions leading to pore nucleation during dynamic loading journal February 2021
Simulation of the Hall-Petch effect in FCC polycrystals by means of strain gradient crystal plasticity and FFT homogenization journal January 2020
Frank-Read source operation in six body-centered cubic refractory metals journal August 2020
The TriBeam system: Femtosecond laser ablation in situ SEM journal February 2015
Hall–Petch behaviour induced by plastic strain gradients journal January 2004
Orientation gradients and geometrically necessary dislocations in ultrafine grained dual-phase steels studied by 2D and 3D EBSD journal April 2010
Comparison between current models for the strength of particulate-reinforced metal matrix nanocomposites with emphasis on consideration of Hall–Petch effect journal January 2012
An experimental statistical analysis of stress projection factors in BCC tantalum journal October 2013
Development of local plasticity around voids during tensile deformation journal May 2021
Resolving the geometrically necessary dislocation content by conventional electron backscattering diffraction journal June 2008
Associating damage nucleation and distribution with grain boundary characteristics in Ta journal October 2020
Statistical analysis of dislocations and dislocation boundaries from EBSD data journal August 2017
Stress and Strain Rate Effects on Incipient Spall in Tantalum journal January 2018
On the influence of loading profile upon the tensile failure of stainless steel journal May 2007
Modeling of grain size strengthening in tantalum at high pressures and strain rates conference January 2017
Implementation and application of a gradient enhanced crystal plasticity model conference January 2017
Effect of peak stress and tensile strain-rate on spall in tantalum journal August 2018
Spall fracture in additive manufactured tantalum journal December 2018
Prediction of void growth using gradient enhanced polycrystal plasticity conference January 2019
Shock recompaction of spall damage journal June 2020
Entropic effect on the rate of dislocation nucleation journal March 2011
The deformation of plastically non-homogeneous materials journal February 1970
Computational design of recovery experiments for ductile metals journal August 2005
The effect of crystal orientation on the indentation response of commercially pure titanium: experiments and simulations journal November 2009
Size Effects on Cavitation Instabilities journal May 2005
Microstructure of cold-rolled copper journal August 1979
Slip planes in bcc transition metals journal June 2013
DREAM.3D: A Digital Representation Environment for the Analysis of Microstructure in 3D journal April 2014