ASTM E821-96(2009)

Standard Practice for Measurement of Mechanical Properties During Charged-Particle Irradiation

ABSTRACT
This practice covers the measurement of the mechanical properties of materials during charged-particle irradiation, with the test materials designed to simulate or provide understanding of, or both, the mechanical behavior of materials when exposed to neutron irradiation. This practice includes requirements for test material and particle beam characterization (such as for strain, load, temperature monitoring and control, and specimen environment monitoring), and recommended procedures for measuring mechanical properties and for calculating radiation damage (such as particle ranges, damage energy, damage rates, and damage gradients). Methods for comparing ion damage with neutron damage are also recommended.
SCOPE
1.1 This practice covers the performance of mechanical tests on materials being irradiated with charged particles. These tests are designed to simulate or provide understanding of, or both, the mechanical behavior of materials during exposure to neutron irradiation. Practices are described that govern the test material, the particle beam, the experimental technique, and the damage calculations. Reference should be made to other ASTM standards, especially Practice E 521. Procedures are described that are applicable to creep and creep rupture tests made in tension and torsion test modes.  
1.2 The word simulation is used here in a broad sense to imply an approximation of the relevant neutron irradiation environment. The degree of conformity can range from poor to nearly exact. The intent is to produce a correspondence between one or more aspects of the neutron and charged particle irradiations such that fundamental relationships are established between irradiation or material parameters and the material response.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Jul-2009
• ICS: 19.100 - Non-destructive testing
• Technical Committee: E10 - Nuclear Technology and Applications

Relations

• Replaces: ASTM E821-96(2003) - Standard Practice for Measurement of Mechanical Properties During Charged-Particle Irradiation
• Effective Date: 01-Aug-2009
• Referred By: ASTM E521-23 - Standard Practice for Investigating the Effects of Neutron Radiation Damage Using Charged-Particle Irradiation
• Effective Date: 01-Aug-2009
• Referred By: ASTM E693-23 - Standard Practice for Characterizing Neutron Exposures in Iron and Low Alloy Steels in Terms of Displacements Per Atom (DPA)
• Effective Date: 01-Aug-2009

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E821 − 96 (Reapproved 2009)
Standard Practice for
Measurement of Mechanical Properties During Charged-
Particle Irradiation
This standard is issued under the fixed designation E821; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
PART I—EXPERIMENTAL PROCEDURE 2. Referenced Documents
2.1 ASTM Standards:
1. Scope
E170Terminology Relating to Radiation Measurements and
1.1 This practice covers the performance of mechanical
Dosimetry
testsonmaterialsbeingirradiatedwithchargedparticles.These E521Practice for Neutron Radiation Damage Simulation by
tests are designed to simulate or provide understanding of, or
Charged-Particle Irradiation
both, the mechanical behavior of materials during exposure to
3. Terminology
neutron irradiation. Practices are described that govern the test
3.1 Definitions:
material,theparticlebeam,theexperimentaltechnique,andthe
3.1.1 Descriptions of relevant terms are found in Terminol-
damage calculations. Reference should be made to other
ASTM standards, especially Practice E521. Procedures are ogy E170.
described that are applicable to creep and creep rupture tests
4. Specimen Characterization
made in tension and torsion test modes.
4.1 Source Material Characterization:
1.2 The word simulation is used here in a broad sense to
4.1.1 The source of the material shall be identified. The
imply an approximation of the relevant neutron irradiation
chemicalcompositionofthesourcematerial,assuppliedbythe
environment.Thedegreeofconformitycanrangefrompoorto
vendor or of independent determination, or both, shall be
nearly exact. The intent is to produce a correspondence
stated. The analysis shall state the quantity of trace impurities.
between one or more aspects of the neutron and charged
Thematerial,heat,lot,orbatch,etc.,numbershallbestatedfor
particle irradiations such that fundamental relationships are
commercial material. The analytical technique and composi-
established between irradiation or material parameters and the
tional uncertainties should be stated.
material response.
4.1.2 The material form and history supplied by the vendor
1.3 The values stated in SI units are to be regarded as shall be stated. The history shall include the deformation
standard. No other units of measurement are included in this
process (rolling, swaging, etc.), rate, temperature, and total
standard. extentofdeformation(givenasstraincomponentsorgeometri-
cal shape changes). The use of intermediate anneals during
1.4 This standard does not purport to address all of the
processing shall be described, including temperature, time,
safety concerns, if any, associated with its use. It is the
environment, and cooling rate.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
4.2 Specimen Preparation and Evaluation:
bility of regulatory limitations prior to use.
4.2.1 The properties of the test specimen shall represent the
properties of bulk material. Since thin specimens usually will
be experimentally desirable, a specimen thickness that yields
This practice is under the jurisdiction of ASTM Committee E10 on Nuclear
bulk properties or information relatable to bulk properties
Technology and Applicationsand is the direct responsibility of Subcommittee
should be selected. This can be approached through either of
E10.08 on Procedures for Neutron Radiation Damage Simulation.
Current edition approved Aug. 1, 2009. Published September 2009. Originally
approved in 1981. Last previous edition approved in 2003 as E821–96(2003). For referenced ASTM standards, visit the ASTM website, www.astm.org, or
DOI: 10.1520/E0821-96R09. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
These practices can be expanded to include mechanical tests other than those Standards volume information, refer to the standard’s Document Summary page on
specified as such experiments are proposed to Subcommittee E10.08. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E821 − 96 (2009)
two techniques: (1) where the test specimen properties exactly neutron irradiation the accelerator, neutron flux and spectrum,
equal bulk material properties; (2) where the test specimen temperature, environment, and stress shall be stated, including
properties are directly relatable to bulk properties in terms of descriptionsofthemeasurementtechniques.Thedpa/sanddpa
deformation mechanisms, but a size effect (surface, texture, should be calculated (see Sections 7-10). For helium implan-
etc.) is present. For the latter case, the experimental justifica- tation using an accelerator, the accelerator, beam energy and
tion shall be reported. current density, beam uniformity, degrader system,
temperature, environment, stress, helium content, and helium
4.2.2 The specimen shape and nominal dimensions shall be
stated and illustrated by a drawing. Deviations from ASTM measurement technique and any post-implantation annealing
shall be stated. The helium distribution shall be calculated as
standards shall be stated. The dimensional measurement tech-
niquesandtheexperimentaluncertaintyofeachshallbestated. shalltheresultingdpa(orshowntobenegligible);seeSections
7 and 8 and Practice E521 for assistance. If another helium
Themethodofspecimenpreparation,suchasmilling,grinding,
etc.,shallbestated.Thedegreeofstraightness,flatness,surface implantation technique is used, a description shall be given of
thetechnique.Itisrecommendedthatchemicalanalysisfollow
condition,edges,fillets,etc.,shallbedescribed.Themethodof
gripping the specimen during the test shall be stated and, any of the above preconditioning procedures.
4.3.2 The microstructure of irradiation preconditioned ma-
preferably, illustrated by a drawing.
terial shall be characterized with respect to dislocation loop
4.2.3 The heat treatment conditions such as time,
size and density, total dislocation density, voids, and any
temperature, atmosphere, cooling rate, etc., shall be stated.
microstructural changes from the unirradiated condition.
Because of the small specimen dimensions, it is essential to
Specimen density changes or dimensional changes shall be
anneal in a non-contaminating environment. Reanalysis for O,
reported.Itisrecommendedthatchangesinhardnessortensile
N, C, and other elements that are likely to change in concen-
strength, or both, be reported. Furthermore, any change in
tration during heat treatment is recommended.
surface condition, including coloration, shall be reported.
4.2.4 Specialcareshallbeexercisedduringspecimenprepa-
ration to minimize surface contamination and irregularities
4.4 Analysis After Charged-Particle Irradiation:
because of the possible effect the surface can have on the flow
4.4.1 The physical, mechanical, and chemical properties of
properties of small specimens. Visible surface contamination
the specimen should be characterized prior to irradiation and
during heat treatment shall be reported as a discoloration or,
any irradiation-induced changes reported. Practice E521 pro-
preferably, characterized using surface analysis technique. It is
videsinformationonpost-irradiationspecimenpreparationand
recommended that surface roughness be characterized.
examination.
4.2.5 The preirradiation microstructure shall be thoroughly
4.4.2 After charged-particle irradiation, the specimen di-
evaluated and reported, including grain size, grain shape,
mensions and density shall be measured. The microstructure
crystallographic texture, dislocation density and morphology,
and surface conditions shall be reexamined, with changes
precipitate size, density, type, and any other microstructural
being reported. Chemical analysis for those elements likely to
features considered significant. When reporting TEM results,
change during the mechanical test (O, C, N, H) shall be
the foil normal and diffracting conditions shall be stated. The
performed on the test specimen or on a dummy specimen held
specimen preparation steps for optical and transmission elec-
under conditions closely approximating those during irradia-
tron microscopy shall be stated.
tion. It is recommended that changes in hardness, tensile
4.2.6 Thepreirradiationmechanicalpropertiesshallbemea-
strength, or creep strength, or both, be measured and reported.
sured and reported to determine deviations from bulk behavior
and to determine baseline properties for irradiation measure-
5. Particle Beam Characterization
ments.Itisrecommendedthatcreepratesbemeasuredforeach
5.1 Beam Composition and Energy:
specimen before and after irradiation (see section 3.4 for more
5.1.1 Most accelerator installations include a calibrated
detail). The thermal creep rate shall be obtained under condi-
magnetic analysis system which ensures beam purity and
tions as close as possible to those existing during irradiation.
provides measurement and control of the energy and energy
The temperature, strain rate, atmosphere, etc., shall be stated.
spread,bothofwhichshouldbereported.Apossibleexception
4.2.7 It is recommended that other material properties
will occur if analogue beams are accelerated. For example, a
including microhardness, resistivity ratio, and density be mea-
16 4+
cyclotron can produce simultaneous beams of O (Z/A= ⁄4)
sured and reported to improve interlaboratory comparison.
12 3+ 2
and C (Z/A= ⁄4) at different energies (E+ E Z /A) which
o
4.3 Irradiation Preconditioning: cannot easily be separated magnetically or electrostatically.
4.3.1 Frequently the experimental step preceding charged- This situation, normally only significant for heavy ion beams,
particle irradiation will involve neutron irradiation or helium can be avoided by judicious choice of charge state and energy.
implantation. This section contains procedures that character- For Van de Graaff accelerators analogue beams of light ions,
+ ++
ize the environment and the effects of this irradiation precon- such as D and He , can be generated, and under certain
circumstances involving two stage acceleration and further
ditioning. For reactor irradiations the reactor, location in
+ + ++
reactor, neutron flux, flux history and spectrum, temperature, ionization (for example, He → 5 MeV He → 5 MeV He ),
beams of impurity ions can be produced that may not be easily
environment, and stress shall be reported. The methods of
+
determining these quantities shall also be reported. The dis- separated from the primary beam (for example, 5 MeV H ).
placement rate (dpa/s) and total displacement (dpa) shall be 5.1.2 For most cases, ion sources are sufficiently pure to
calculated; see Practice E521 for directions. For ex-reactor remove any concern of significant beam impurity, but this
E821 − 96 (2009)
problem should be considered. Beam energy attenuation and this should be reported. When scanning a pulsed beam at a
changes in the divergence of the beam passing through subharmonicofitsnaturalfrequencyitshouldbenotedthatthe
windows and any gaseous medium shall be estimated and beam spot will strike the specimen at discrete locations, rather
reported. than be distributed continuously across the specimen. The raw
beam spot must therefore be considerably larger than the
5.2 Spatial Variation in Beam Intensity:
distance between these locations or a very non-uniform inten-
5.2.1 The quantity of interest is beam intensity/unit area at
sity distribution will result. It is most desirable to use a
thespecimen.Itisusuallydesirabletoproduceauniformbeam
continuous rather than rastered beam. If a rastered beam is
density over the specimen area so that this quantity can be
used, the degree of defect annealing between pulses shall be
inferred from a measurement of the total beam intensity and
considered.
area.
5.2.2 Total beam intensity should be measured using a
6. Mechanical Testing Apparatus
Faraday cup whenever possible; however, this may not be
6.1 Strain Measurement:
possible on a continuous basis during irradiation. The Faraday
−5
6.1.1 The strains measured during light ion irradiation tests,
cup shall be evacuated to P<10 and shall be electron-
for measurement periods ;1 day and for conditions where the
suppressed; otherwise, spurious results may be generated.
irradiation has a significant effect on the elongation rate, are
Various secondary beam monitors may then be used, such as
−3 −5
very small (typically ;10 to 10 ). Therefore, the strain
ionization chambers, secondary emission monitors, transform-
resolution normally required for continuous measurements is 1
ers or other induction devices (for pulsed beams), beam
−6
to 10×10 . The strain resolution as well as displacement
scanners, or particles scattered from a foil. All such devices
resolution shall be reported.
shall be calibrated through Faraday cup measurements or
6.1.2 Normally for these experiments the limiting factor in
through activation analysis. These calibrations shall be re-
strain measurement is not the resolution of the actual displace-
ported.
ment measuring device (for example, LVDT, LVDC, strain
5.2.3 Displacement rate gradients occur in charged-particle
gage, laser extensometer, etc.); it is the ability of the apparatus
irradiation specimens in the Z (beam) direction because of
to transmit the displacement with fidelity. To minimize these
changes in ion energy and, therefore, displacement cross
displacement measurement errors it is recommended that the
sectionwithpenetration(see10.5.1),andinthe Xand Y(lateral
temperature be monitored or controlled, or both, on each
and longitudinal specimen axes, respectively) directions be-
critical part of the apparatus and that thermal sensitivity
cause of spatial variations in beam intensity.
experiments be performed; that is, a local temperature fluctua-
NOTE 1—Non-uniform specimen cross section may give rise to dis-
tion should be imposed on individual elements of the strain
placement rate variations in the x- and y-directions, even under a
measuring system while the strain signal is monitored. It is
spatially-uniform beam.
recommendedthatthestrainsensitivitytoambienttemperature
5.2.3.1 Displacement rate ratios of 1.2 to 2.5 (ratio of
fluctuations be recorded. It is recommended that the strain
displacement rate at exit surface to rate at entrance surface of
sensitivity to vibrations and coolant flow rates be monitored
specimen in the Z direction) are common, but it is recom-
and reported. The strainmeasuring resolution, lin
...