ASTM E2712-09e1

Standard Test Methods for Forming Superplastic Metallic Sheet

SIGNIFICANCE AND USE
When a superplastic material is regularly being used in industrial production, it is often convenient to use the bulge test to qualify a batch or heat lot to an acceptance criterion. Comparing these test methods with Test Method E2448, the bulge test does not require a machined coupon, it is more convenient to perform, and it most closely simulates the multiaxial stresses and strains present in forming parts. These test methods do not measure the intrinsic superplastic properties of a material. Test Method E2448 should be used in that instance.
SCOPE
1.1 These test methods describe procedures for determining the biaxial formability of a superplastic metallic sheet in a circular die.
1.2 The intent of these test methods are primarily to be used as tests of superplasticity as measured by the ability to form to a prescribed depth in a die cavity without rupturing. These test methods can also be used to generate material for the measurement of cavitation in the formed part. These can be used as go/no go criteria for qualification to a specification.
1.3 These test methods have been used successfully with aluminum alloys. The use of these test methods on other metals should be verified.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 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-Aug-2009
• ICS: 77.140.50 - Flat steel products and semi-products
• Technical Committee: E28 - Mechanical Testing
• Drafting Committee: E28.02 - Ductility and Formability

Relations

• Replaces: ASTM E2712-09 - Standard Test Methods for Forming Superplastic Metallic Sheet
• Effective Date: 01-Sep-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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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
´1
Designation: E2712 − 09
StandardTest Methods for
1
Bulge-Forming Superplastic Metallic Sheet
This standard is issued under the fixed designation E2712; 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.
1
ε NOTE—The title was editorially corrected in October 2009.
1. Scope 3.1.1 In the first test method, the sheet is formed into a die
ofafixeddepthasprescribedinaspecification.Ifittouchesthe
1.1 These test methods describe procedures for determining
base of the die without rupturing, then it is considered to have
the biaxial formability of a superplastic metallic sheet in a
met the specification.
circular die.
3.1.2 In the second test method, the depth of the die is
1.2 Theintentofthesetestmethodsareprimarilytobeused
reducedsothatthematerialfillsthedie.Aportionexcisedfrom
as tests of superplasticity as measured by the ability to form to
the center of the formed part can be examined for internal
a prescribed depth in a die cavity without rupturing.These test
cavitation within the sheet.
methodscanalsobeusedtogeneratematerialforthemeasure-
4. Significance and Use
ment of cavitation in the formed part. These can be used as
go/no go criteria for qualification to a specification.
4.1 When a superplastic material is regularly being used in
industrialproduction,itisoftenconvenienttousethebulgetest
1.3 These test methods have been used successfully with
to qualify a batch or heat lot to an acceptance criterion.
aluminumalloys.Theuseofthesetestmethodsonothermetals
Comparing these test methods with Test Method E2448, the
should be verified.
bulge test does not require a machined coupon, it is more
1.4 The values stated in SI units are to be regarded as
convenient to perform, and it most closely simulates the
standard. No other units of measurement are included in this
multiaxial stresses and strains present in forming parts. These
standard.
test methods do not measure the intrinsic superplastic proper-
ties of a material. Test Method E2448 should be used in that
1.5 This standard does not purport to address all of the
instance.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
5. Apparatus
priate safety and health practices and determine the applica-
5.1 The bulge test consists of forming a sheet of material
bility of regulatory limitations prior to use.
into a right circular cylindrical die using pressurized gas. The
apparatus is shown in Fig. 1. The die cavity has a 100-mm
2. Referenced Documents
diameterandaspecifieddepthinavesselsuitablydesignedfor
2
2.1 ASTM Standards:
thepressureandtemperatureenvisagedforthetest.Thesurface
E2448Test Method for Determining the Superplastic Prop-
finish of the die cavity shall be 0.4 micrometer.
erties of Metallic Sheet Materials
5.2 The depth of the die (X in Fig. 1), can be varied by
means of inserts or other methods to the depth set by the
3. Summary of Test Method
specification.Adepth of 55 mm has been successfully used on
3.1 Twomethodsofbulgeformingareincludedinthesetest
superplastic-forming (SPF) 5083 aluminum alloy. For
methods.
convenience, a series of inserts of different heights can be
installed in the die to provide different depths according to the
bulgetestrequirements.Theinsertmustallowthefreepassage
1
of gas around its periphery to the exhaust hole in the die.
This test method is under the jurisdiction of ASTM Committee E28 on
Mechanical Testing and is the direct responsibility of Subcommittee E28.02 on
5.3 The die entry radius is 5 mm. A lower plate with a
Ductility and Formability.
control thermocouple can be moved to press against the die.
Current edition approved Sept. 1, 2009. Published Ocotober 2009. DOI:
10.1520/E2712-09E01.
The plate has a gas seal bead 0.7 mm high by 8 mm wide and
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
a 136-mm inside diameter.Agas pressurization system with a
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
gauge or other suitable means of measuring pressure and
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. detecting sheet failure shall be provided at the lower plate to
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
´1
E2712 − 09
FIG. 1 Bulge-Forming Apparatus
production, lubricant adds an unnecessary variable to the test method,
form the material into the cavity. The pressure tolerance up to
which is why it should not generally be use
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
´1
Designation:E2712–09 Designation: E2712 – 09
Standard Test Methods for
1
Bulge-Forming Superplastic Metallic Sheet
This standard is issued under the fixed designation E2712; 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
´ NOTE—The title was editorially corrected in October 2009.
1. Scope
1.1 These test methods describe procedures for determining the biaxial formability of a superplastic metallic sheet in a circular
die.
1.2 The intent of these test methods are primarily to be used as tests of superplasticity as measured by the ability to form to
a prescribed depth in a die cavity without rupturing. These test methods can also be used to generate material for the measurement
of cavitation in the formed part. These can be used as go/no go criteria for qualification to a specification.
1.3 These test methods have been used successfully with aluminum alloys.The use of these test methods on other metals should
be verified.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 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.
2. Referenced Documents
2
2.1 ASTM Standards:
E2448 Test Method for Determining the Superplastic Properties of Metallic Sheet Materials
3. Summary of Test Method
3.1 Two methods of bulge forming are included in these test methods.
3.1.1 In the first test method, the sheet is formed into a die of a fixed depth as prescribed in a specification. If it touches the
base of the die without rupturing, then it is considered to have met the specification.
3.1.2 Inthesecondtestmethod,thedepthofthedieisreducedsothatthematerialfillsthedie.Aportionexcisedfromthecenter
of the formed part can be examined for internal cavitation within the sheet.
4. Significance and Use
4.1 When a superplastic material is regularly being used in industrial production, it is often convenient to use the bulge test to
qualify a batch or heat lot to an acceptance criterion. Comparing these test methods with Test Method E2448, the bulge test does
not require a machined coupon, it is more convenient to perform, and it most closely simulates the multiaxial stresses and strains
present in forming parts. These test methods do not measure the intrinsic superplastic properties of a material. Test Method E2448
should be used in that instance.
5. Apparatus
5.1 Thebulgetestconsistsofformingasheetofmaterialintoarightcircularcylindricaldieusingpressurizedgas.Theapparatus
is shown in Fig. 1. The die cavity has a 100-mm diameter and a specified depth in a vessel suitably designed for the pressure and
temperature envisaged for the test. The surface finish of the die cavity shall be 0.4 micrometer.
5.2 The depth of the die (X in Fig. 1), can be varied by means of inserts or other methods to the depth set by the specification.
A depth of 55 mm has been successfully used on superplastic-forming (SPF) 5083 aluminum alloy. For convenience, a series of
inserts of different heights can be installed in the die to provide different depths according to the bulge test requirements.The insert
must allow the free passage of gas around its periphery to the exhaust hole in the die.
1
This test method is under the jurisdiction of ASTM Committee E28 on Mechanical Testing and is the direct responsibility of Subcommittee E28.02 on Ductility and
Formability.
Current edition approved Sept. 1, 2009. Published Ocotober 2009. DOI: 10.1520/E2712-09.
2
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at [e-mail]. For Annual Book ofASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
´1
E2712 – 09
FIG. 1 Bulge-Forming Apparatus
5.3 The die entry radius is 5 mm. A lower plate with a control thermocouple can be moved to press against the die. The plate
has a gas seal bead 0.7 mm high by 8 mm wide and a 136-mm in
...