ASTM D6411/D6411M-99

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D 6411/D 6411M – 99
Standard Specification For
Silicone Rubber Room Temperature Vulcanizing Low
Outgassing Materials
This standard is issued under the fixed designation D 6411/D 6411M; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope at Commercial Power Frequencies
D 150 Test Methods for AC Loss Characteristics and Per-
1.1 Thespecificationcoversatwo-partflowablespacegrade
mittivity (Dielectric Constant) of Solid Electrical Insula-
room temperature vulcanizing (RTV) silicone rubber adhesive
tion
or compound. The material is specifically designed for appli-
D 257 Test Methods for DC Resistance or Conductance of
cations requiring extreme low temperature, low outgassing and
Insulating Materials
minimal volatile condensibles under extreme operating condi-
D 412 Test Methods for Vulcanized Rubber and Thermo-
tions. The RTV silicone rubber should be suitable for with-
plastic Elastomers - Tension
standing environmental exposure to temperatures from –115 to
D 792 Test Method for Density and Specific Gravity (Rela-
200°C (–175 to 392°F). The material should also withstand the
tive Density) of Plastics by Displacement
combination of stress, temperature, and relative humidity
D 907 Terminology of Adhesives
expectedtobeencounteredinservice.TheRTVsiliconerubber
D 1002 Test Method forApparent Shear Strength of Single-
may be used as a sealing, caulking, potting or bonding material
LapJointAdhesivelyBondedMetalSpecimensbyTension
for applications on metal, plastics, rubber, glass, and ceramic
Loading (Metal-to-Metal)
products. Types I and II are often used as coatings.
D 1084 Test Method for Viscosity of Adhesives
1.2 The values stated in SI units or inch-pound units are to
D 2240 Test Method for Rubber Property Durometer Hard-
be regarded separately as standard. Within the text, the
ness
inch-pound units are shown in brackets. The values stated in
D 2651 Guide for Preparation of Metal Surfaces for Adhe-
each system are not exact equivalents; therefore, each system
sive Bonding
must be used independently of the other. Combining values
D 3951 Practice for Commercial Packaging
from the two systems may result in nonconformance with this
E 595 Test Method for Total Mass Loss and Collected
specification.
Volatile Condensable Materials from Outgassing in a
1.3 The following precautionary statement refers to the test
Vacuum Environment
method portion only, Section 8, of this specification: This
2.2 National Aeronautics and Space Administration
standard does not purport to address all of the safety concerns,
(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
2. Referenced Documents
Hardware Systems
GSFC RP 1124 Outgassing Data for Selecting Spacecraft
2.1 ASTM Standards:
Materials
B 209 Specification for Aluminum and Aluminum–Alloy,
Sheet and Plate
D 149 Test Method for Dielectric Breakdown Voltage and
Dielectric Strength of Solid Electrical Insulating Materials
Annual Book of ASTM Standards, Vol 10.01.
Annual Book of ASTM Standards, Vol 09.01.
Annual Book of ASTM Standards, Vol 08.01.
1 6
This specification is under the jurisdiction of ASTM Committee D-14 on Annual Book of ASTM Standards, Vol 15.06.
adhesivesandisthedirectresponsibilityofsubcommitteeD14.80onMetalBonding Annual Book of ASTM Standards, Vol 15.09.
Adhesives. Annual Book of ASTM Standards, Vol 15.03.
Current edition approved April 10, 1999. Published July 1999. Unless otherwise indicated, copies of the above documents are available from
Annual Book of ASTM Standards, Vol 02.02. a NASA installation library or document repository.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 6411/D 6411M
NOTE 1—Copiesofspecifications,standards,drawingsandpublications
6.1.3 AmountsandunitquantitiesofRTVrubbercompound
required by suppliers in connection with specific purchases should be
required,
obtained from the purchaser or as directed by his contracting officer.
6.1.4 Curing conditions,
6.1.5 Level of packaging and packing required,
3. Terminology
6.1.6 Whether or not qualification is necessary, and
3.1 Definitions—Many terms in this specification are de-
6.1.7 Storage conditions.
fined in Terminology D 907.
6.2 Qualification—In case the RTV silicone rubber com-
3.1.1 lot, n—a specific material that can be identified by the
pound(s) that are qualified/approved at the time set for opening
place of manufacture, quantity and type of raw materials and
of bids, the procurement documents should state that the
process conditions used.
awards will be forthcoming.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 RTV, adj—room temperature vulcanizing.
7. Test Requirements
3.2.2 RTV Silicone Rubber Compound, n—a silicone resin
7.1 Material—The RTV silicone rubber compound, when
base (A) and a silicone resin curing agent (B) when mixed in a
tested per Section 8, shall meet the physical, mechanical and
proper ratio results in a rubbery compound. A RTV silicone
electrical, and outgassing requirements as specified in Table 1.
rubber compound that is manufactured by a unique combina-
The silicone rubber compound shall not have a detrimental
tion of raw silicone materials and manufacturing process that
effect on surfaces being in contact or bonded over the range of
conforms to a given set of physical and performance properties
temperaturesatwhichtheRTVsiliconerubbercompoundswill
and is identified by specific name, number, or alphanumeric
be used.
designation.
7.2 Qualification—Qualification shall only apply to the
NOTE 2—A“curing agent” is commonly used with this type of silicone
formulation on which the qualification tests have been made;
rubber compound. The term “accelerator” or “catalyst” is synonymous
any changes by the manufacturer in formulation or method of
with “curing agent.”
manufacturing, shall be cause of designating the RTV silicone
rubber compound as a new product. The new product shall be
4. Significance and Use
givenanewcodenumberandshallberequalifiedandapproved
4.1 General—This specification provides material require-
until it has been shown to meet the requirements of this
ments and testing procedures to differentiate between the
specification.
physical, mechanical, electrical, adhesive bonding properties
7.3 Working Characteristics:
of three types of RTV silicone rubber compounds.
7.3.1 Application—The RTV silicone rubber compound
4.2 Thephysical,mechanicalandelectricalpropertiesofthe
shall be suitable for application to surfaces in accordance with
RTV silicone rubber are tested and measured to provide
the manufacturer’s instructions.
specific data on requirements for qualification and lot accep-
7.3.2 Curing—The time, temperature, and pressure used to
tance of separate ingredients comprising the RTV silicone
cure the RTV silicone rubber compound shall be in accordance
rubber compounds and the properties resulting from the cured
with the manufacturer’s recommendation.
mixture.
8. Test Methods
NOTE 3—Because of the many number of adherend materials bonded
with RTV silicone rubber material, testing by this specification will only
8.1 Qualification Tests—For qualification, the RTV silicone
evaluate the RTV silicone rubber material under a given set of conditions.
rubber compound shall be tested using the tests described in
this section.All tests specified in Table 1 shall be performed at
5. Classification
room temperature, 25 6 3°C [77 6 5°F] with the exception of
5.1 The RTV low volatile silicone rubber compounds shall
the outgassing test.
be furnished as one of the following types:
8.2 Preparation of Test Specimens—Prepare at least ten
5.1.1 Type I—Alow viscosity, two-part system consists of a
specimens for each separate test as follows:
silicone resin base (A) and a liquid curing agent (B) when
8.2.1 Tensile Shear Strength Specimens:
mixed and cured results in a Shore A hardness of 60.
8.2.1.1 Adherend—The metal substrate shall be 6061-T6 or
5.1.2 Type II—A medium viscosity, two-part system con-
2024-T3 aluminum alloy in accordance with Specification
sists of a silicone resin base (A) and a liquid curing agent (B)
B 209.
when mixed and cured results in a Shore A hardness o
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