ASTM E963-95(2010)

Standard Practice for Electrolytic Extraction of Phases from Ni and Ni-Fe Base Superalloys Using a Hydrochloric-Methanol Electrolyte

SIGNIFICANCE AND USE
This practice can be used to extract carbides, borides, TCP and GCP phases, which can then be qualitatively or quantitatively analyzed by X-ray diffraction or microanalysis.  
Careful control of parameters is necessary for reproducible quantitative results. Within a given laboratory, such results can be obtained routinely; however, caution must be exercised when comparing quantitative results from different laboratories.  
Comparable qualitative results can be obtained routinely among different laboratories using this procedure.
SCOPE
1.1 This practice covers a procedure for the isolation of carbides, borides, TCP (topologically close-packed), and GCP (geometrically close-packed) phases (Note 1) in nickel and nickel-iron base gamma prime strengthened alloys. Contamination of the extracted residue by coarse matrix (gamma) or gamma prime particles, or both, reflects the condition of the alloy rather than the techniques mentioned in this procedure.
1.2 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-Mar-2010
• ICS: 77.120.40 - Nickel, chromium and their alloys
• Technical Committee: E04 - Metallography
• Drafting Committee: E04.11 - X-Ray and Electron Metallography

Relations

• Replaces: ASTM E963-95(2004) - Standard Practice for Electrolytic Extraction of Phases from Ni and Ni-Fe Base Superalloys Using a Hydrochloric-Methanol Electrolyte
• Effective Date: 01-Apr-2010
• Replaced By: ASTM E963-95(2017) - Standard Practice for Electrolytic Extraction of Phases from Ni and Ni-Fe Base Superalloys Using a Hydrochloric-Methanol Electrolyte (Withdrawn 2018)
• Effective Date: 01-Jun-2017

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: E963 − 95 (Reapproved 2010)
Standard Practice for
Electrolytic Extraction of Phases from Ni and Ni-Fe Base
1
Superalloys Using a Hydrochloric-Methanol Electrolyte
This standard is issued under the fixed designation E963; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Significance and Use
1.1 This practice covers a procedure for the isolation of 3.1 This practice can be used to extract carbides, borides,
carbides, borides, TCP (topologically close-packed), and GCP TCP and GCP phases, which can then be qualitatively or
2
(geometrically close-packed) phases (Note 1) in nickel and quantitatively analyzed by X-ray diffraction or microanalysis.
nickel-iron base gamma prime strengthened alloys. Contami-
3.2 Careful control of parameters is necessary for reproduc-
nation of the extracted residue by coarse matrix (gamma) or
ible quantitative results.Within a given laboratory, such results
gamma prime particles, or both, reflects the condition of the
can be obtained routinely; however, caution must be exercised
alloy rather than the techniques mentioned in this procedure.
when comparing quantitative results from different laborato-
3
1.2 This standard does not purport to address all of the
ries.
safety concerns, if any, associated with its use. It is the
3.3 Comparablequalitativeresultscanbeobtainedroutinely
responsibility of the user of this standard to establish appro- 3
among different laboratories using this procedure.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. (See 3.3.2.1 and
4. Apparatus
4.1.1.)
4.1 Cell or Container for Electrolyte— A glass vessel of
NOTE 1—Ni Ti (eta phase) has been found to be soluble in the
about 400-mL capacity is recommended. For the sample size
3
electrolyte for some alloys.
and current density recommended later in this procedure,
electrolysis can proceed up to about 4 h, and up to about4gof
2. Terminology
alloy can be dissolved in 250 mL of electrolyte without
2.1 Definitions:
exceeding a metallic ion concentration of 16 g/L. Above this
2.1.1 extraction cell—laboratory apparatus consisting of a
concentration, cathode plating has been observed to be more
beaker to contain the electrolyte, a dc power supply, a noble
likely to occur. A mechanism for cooling the electrolyte is
metal sheet or screen cathode and a noble metal wire basket or
recommended. For example, an ice water bath or water-
wire to affix to the sample (anode).
jacketed cell may be used to keep the electrolyte between 0°
2.1.2 geometrically close-packed (GCP) phases—
and 30°C.
precipitated phases found in nickel-base alloys that have the
4.2 Cathode—Material must be inert during electrolysis.
form A B, where B is a smaller atom than A. In superalloys,
3
Tantalum and platinum sheet or mesh are known to meet this
these are the common FCC Ni (Al, Ti) or occasionally found
3
requirement. Use of a single wire is to be avoided, since
HCP Ni Ti.
3
cathode surface area should be larger than that of sample.
2.1.3 topologically close-packed (TCP) phases— precipi-
Distance between sample and cathode should be as great as
tated phases in nickel-base alloys, characterized as composed
possible, within the size of cell chosen. For example, a sample
of close-packed layers of atoms forming in basket weave nets
2
with a surface area of 15 cm should have no side closer than
aligned with the octahedral planes of the FCC γ matrix. These
1.2 cm to the cathode. If the cell is cylindrical, as for the case
generally detrimental phases appear as thin plates, often
ofabeakerortheupperpartofaseparatoryfunnel,thecathode
nucleating on grain-boundary carbides. TCPphases commonly
could be curved to fit the inner cell wall to facilitate correct
found in nickel alloys are σ, µ , and Laves.
sample-cathode distance. The sample would then be centered
1 2
This practice is under the jurisdiction of ASTM Committee E04 on Metallog- Donachie, M. J. Jr., and Kriege, O. H., “Phase Extraction and Analysis in
raphy and is the direct responsibility of Subcommittee E04.11 on X-Ray and Superalloys—Summary of Investigations byASTM Committee E-4 Task Group I,”
Electron Metallography. Journal of Materials , Vol 7, 1972, pp. 269–278.
3
Current edition approved April 1, 2010. Published May 2010. Originally Donachie, M. J. Jr., “Phase Extraction and Analysis in Superalloys—Second
approved in 1983. Last previous edition approved in 2004 as E963 – 95 (2004). Summary of Investigations by ASTM Subcommittee E04.91,” Journal of Testing
DOI: 10.1520/E0963-95R10. and Evaluation, Vol 6, No.
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