ASTM D6411/D6411M-99(2005)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D6411/D6411M −99(Reapproved2005)
Standard Specification For
Silicone Rubber Room Temperature Vulcanizing Low
Outgassing Materials
This standard is issued under the fixed designation D6411/D6411M; 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 D149 Test Method for Dielectric Breakdown Voltage and
DielectricStrengthofSolidElectricalInsulatingMaterials
1.1 Thespecificationcoversatwo-partflowablespacegrade
at Commercial Power Frequencies
room temperature vulcanizing (RTV) silicone rubber adhesive
D150 Test Methods forAC Loss Characteristics and Permit-
or compound. The material is specifically designed for appli-
tivity (Dielectric Constant) of Solid Electrical Insulation
cations requiring extreme low temperature, low outgassing and
D257 Test Methods for DC Resistance or Conductance of
minimal volatile condensibles under extreme operating condi-
Insulating Materials
tions. The RTV silicone rubber should be suitable for with-
D412 Test Methods forVulcanized Rubber andThermoplas-
standing environmental exposure to temperatures from –115 to
tic Elastomers—Tension
200°C (–175 to 392°F).The material should also withstand the
D792 Test Methods for Density and Specific Gravity (Rela-
combination of stress, temperature, and relative humidity
tive Density) of Plastics by Displacement
expectedtobeencounteredinservice.TheRTVsiliconerubber
D907 Terminology of Adhesives
may be used as a sealing, caulking, potting or bonding material
D1002 Test Method for Apparent Shear Strength of Single-
for applications on metal, plastics, rubber, glass, and ceramic
Lap-Joint Adhesively Bonded Metal Specimens by Ten-
products. Types I and II are often used as coatings.
sion Loading (Metal-to-Metal)
1.2 The values stated in SI units or inch-pound units are to
D1084 Test Methods for Viscosity of Adhesives
be regarded separately as standard. Within the text, the
D2240 Test Method for Rubber Property—Durometer Hard-
inch-pound units are shown in brackets. The values stated in
ness
each system are not exact equivalents; therefore, each system
D2651 GuideforPreparationofMetalSurfacesforAdhesive
must be used independently of the other. Combining values
Bonding
from the two systems may result in nonconformance with this
D3951 Practice for Commercial Packaging
specification.
E595 Test Method for Total Mass Loss and Collected Vola-
1.3 The following precautionary statement refers to the test tile Condensable Materials from Outgassing in a Vacuum
method portion only, Section 8, of this specification: This
Environment
standard does not purport to address all of the safety concerns, 2.2 National Aeronautics and Space Administration (NASA)
if any, associated with its use. It is the responsibility of the user
JSC SP-R-0022 General Specification, Vacuum Stability
of this standard to establish appropriate safety and health Requirement of Polymeric Material for Spacecraft Appli-
practices and determine the applicability of regulatory limita-
cation
tions prior to use. MSFC-HDBK-527/JSC-09604 Material Selection List for
Hardware Systems
2. Referenced Documents
GSFC RP 1124 Outgassing Data for Selecting Spacecraft
2.1 ASTM Standards:
Materials
B209 Specification for Aluminum and Aluminum-Alloy
NOTE1—Copiesofspecifications,standards,drawingsandpublications
Sheet and Plate
required by suppliers in connection with specific purchases should be
obtained from the purchaser or as directed by his contracting officer.
This specification is under the jurisdiction of ASTM Committee D14 on
Adhesives and is the direct responsibility of subcommittee D14.80 on Metal 3. Terminology
Bonding Adhesives.
3.1 Definitions:
Current edition approved April 1, 2005. Published May 2005. Originally
approved in 1999. Last previous edition approved in 1999 as D6411/D6411M - 99. 3.1.1 Many terms in this specification are defined in Termi-
DOI: 10.1520/D6411_D6411M-99R05.
nology D907.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Unless otherwise indicated, copies of the above documents are available from
the ASTM website. a NASA installation library or document repository.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6411/D6411M−99(2005)
3.1.2 lot, n—a specific material that can be identified by the 6.1.7 Storage conditions.
place of manufacture, quantity and type of raw materials and
6.2 Qualification—In case the RTV silicone rubber com-
process conditions used.
pound(s) that are qualified/approved at the time set for opening
3.2 Definitions of Terms Specific to This Standard: of bids, the procurement documents should state that the
3.2.1 RTV, adj—room temperature vulcanizing. awards will be forthcoming.
3.2.2 RTV Silicone Rubber Compound, n—a silicone resin
7. Test Requirements
base (A) and a silicone resin curing agent (B) when mixed in a
proper ratio results in a rubbery compound. A RTV silicone
7.1 Material—The RTV silicone rubber compound, when
rubber compound that is manufactured by a unique combina-
tested per Section 8, shall meet the physical, mechanical and
tion of raw silicone materials and manufacturing process that
electrical, and outgassing requirements as specified in Table 1.
conforms to a given set of physical and performance properties
The silicone rubber compound shall not have a detrimental
and is identified by specific name, number, or alphanumeric
effect on surfaces being in contact or bonded over the range of
designation.
temperaturesatwhichtheRTVsiliconerubbercompoundswill
be used.
NOTE 2—A“curing agent” is commonly used with this type of silicone
rubber compound. The term “accelerator” or “catalyst” is synonymous
7.2 Qualification—Qualification shall only apply to the
with “curing agent.”
formulation on which the qualification tests have been made;
any changes by the manufacturer in formulation or method of
4. Significance and Use
manufacturing, shall be cause of designating the RTV silicone
4.1 General—This specification provides material require-
rubber compound as a new product. The new product shall be
ments and testing procedures to differentiate between the
givenanewcodenumberandshallberequalifiedandapproved
physical, mechanical, electrical, adhesive bonding properties
until it has been shown to meet the requirements of this
of three types of RTV silicone rubber compounds.
specification.
4.2 Thephysical,mechanicalandelectricalpropertiesofthe
7.3 Working Characteristics:
RTV silicone rubber are tested and measured to provide
7.3.1 Application—The RTV silicone rubber compound
specific data on requirements for qualification and lot accep-
shall be suitable for application to surfaces in accordance with
tance of separate ingredients comprising the RTV silicone
the manufacturer’s instructions.
rubber compounds and the properties resulting from the cured
7.3.2 Curing—The time, temperature, and pressure used to
mixture.
cure the RTVsilicone rubber compound shall be in accordance
with the manufacturer’s recommendation.
NOTE 3—Because of the many number of adherend materials bonded
with RTV silicone rubber material, testing by this specification will only
evaluate the RTV silicone rubber material under a given set of conditions.
8. Test Methods
8.1 Qualification Tests—For qualification, the RTV silicone
5. Classification
rubber compound shall be tested using the tests described in
5.1 The RTV low volatile silicone rubber compounds shall
this section.All tests specified in Table 1 shall be performed at
be furnished as one of the following types:
room temperature, 25 6 3°C [77 6 5°F] with the exception of
5.1.1 Type I—Alow viscosity, two-part system consists of a
the outgassing test.
silicone resin base (A) and a liquid curing agent (B) when
8.2 Preparation of Test Specimens—Prepare at least ten
mixed and cured results in a Shore A hardness of 60.
specimens for each separate test as follows:
5.1.2 Type II—A medium viscosity, two-part system con-
8.2.1 Tensile Shear Strength Specimens:
sists of a silicone resin base (A) and a liquid curing agent (B)
8.2.1.1 Adherend—The metal substrate shall be 6061-T6 or
when mixed and cured results in a Shore A hardness of 40.
2024-T3 aluminum alloy in accordance with Specification
5.1.3 Type III—A medium viscosity thixotropic, two-part
B209.
system consists of a silicone resin base (A) and a liquid curing
8.2.1.2 Surface Preparation—Clean and etch in accordance
agent (B) when mixed
...