ASTM E2712-15

Standard Test Methods for Bulge-Forming Superplastic Metallic Sheet

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.
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: 30-Apr-2015
• ICS: 77.140.50 - Flat steel products and semi-products
• Technical Committee: E28 - Mechanical Testing
• Drafting Committee: E28.02 - Ductility and Formability

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: E2712 − 15
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.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.2 In the second test method, the depth of the die is
reducedsothatthematerialfillsthedie.Aportionexcisedfrom
1.1 These test methods describe procedures for determining
the center of the formed part may be examined for internal
the biaxial formability of a superplastic metallic sheet in a
cavitation within the sheet.
circular die.
1.2 Theintentofthesetestmethodsareprimarilytobeused
4. Significance and Use
as tests of superplasticity as measured by the ability to form to
4.1 When a superplastic material is regularly being used in
a prescribed depth in a die cavity without rupturing.These test
industrialproduction,itisoftenconvenienttousethebulgetest
methodscanalsobeusedtogeneratematerialforthemeasure-
to qualify a batch or heat lot to an acceptance criterion.
ment of cavitation in the formed part. These can be used as
Comparing these test methods with Test Method E2448, the
go/no go criteria for qualification to a specification.
bulge test does not require a machined coupon, it is more
1.3 These test methods have been used successfully with
convenient to perform, and it most closely simulates the
aluminumalloys.Theuseofthesetestmethodsonothermetals
multiaxial stresses and strains present in forming parts. These
should be verified.
test methods do not measure the intrinsic superplastic proper-
1.4 The values stated in SI units are to be regarded as
ties of a material. Test Method E2448 should be used in that
standard. No other units of measurement are included in this
instance.
standard.
5. Apparatus
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
5.1 The bulge test consists of forming a sheet of material
responsibility of the user of this standard to establish appro-
into a right circular cylindrical die using pressurized gas. The
priate safety and health practices and determine the applica-
apparatus is shown in Fig. 1. The die cavity has a 100-mm
bility of regulatory limitations prior to use.
diameterandaspecifieddepthinavesselsuitablydesignedfor
thepressureandtemperatureenvisagedforthetest.Thesurface
2. Referenced Documents
finish of the die cavity shall be R =0.4 µm.
2 A
2.1 ASTM Standards:
5.2 The depth of the die (X in Fig. 1), may be varied by
E2448Test Method for Determining the Superplastic Prop-
means of inserts or other methods to the depth set by the
erties of Metallic Sheet Materials
specification. For convenience, a series of inserts of different
3. Summary of Test Method
heights may be installed in the die to provide different depths
3.1 Twomethodsofbulgeformingareincludedinthesetest according to the bulge test requirements.
methods.
NOTE1—Adepthof55mmhasbeensuccessfullyusedonsuperplastic-
3.1.1 In the first test method, the sheet is formed into a die
forming (SPF) 5083 aluminum alloy.
ofafixeddepthasprescribedinaspecification.Ifittouchesthe
5.2.1 The insert shall allow the free passage of gas around
base of the die without rupturing, then it is considered to have
its periphery to the exhaust hole in the die.
met the specification.
5.3 The die entry radius is 5 mm. A lower plate with a
1
This test method is under the jurisdiction of ASTM Committee E28 on
control thermocouple may be moved to press against the die.
Mechanical Testing and is the direct responsibility of Subcommittee E28.02 on
The plate has a gas seal bead 0.7 mm high by 8 mm wide and
Ductility and Formability.
a 136-mm inside diameter.Agas pressurization system with a
CurrenteditionapprovedMay1,2015.PublishedJuly2015.Originallyapproved
ε1
gauge or other suitable means of measuring pressure and
in 2009. Last previous edition approved in 2009 as E2719–09 . DOI: 10.1520/
E2712-15.
detecting sheet failure shall be provided at the lower plate to
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
form the material into the cavity. The pressure tolerance up to
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
1 MPa shall be 650 kPa, and above 1 MPa shall be 65%of
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. pressure.Anexhaustportinthediemaybeconnectedeitherto
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E2712 − 15
FIG. 1 Bulge-Forming Appa
...

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 E2712 − 15
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
ε 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 In the second test method, the depth of the die is reduced so that the material fills the die. A portion excised from the center
of the formed part canmay 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 The bulge test consists of forming a sheet of material into a right circular cylindrical die using pressurized gas. The apparatus
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 0.4R micrometer.=0.4 μm.
A
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, 2009May 1, 2015. Published Ocotober 2009July 2015. Originally approved in 2009. Last previous edition approved in 2009 as
ε1
E2719–09 . DOI: 10.1520/E2712-09E01.10.1520/E2712-15.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM 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 ----------------------
E2712 − 15
FIG. 1 Bulge-Forming Apparatus
5.2 The depth of the die (X in Fig. 1), canmay 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 canmay 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.
NOTE
...