1、 PERFORMANCE SPECIFICATION COATING COMPOUND, THERMAL-INSULATION This specification is approved for use by the Naval Air Systems Command, Department of the Navy, and is available for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers asbest
2、os-free, thermal-insulating coating compound. The thermal protection coating is used for the exterior surfaces of aircraft ordnance to delay cook-off during exposure to a liquid fuel fire (see 6.1). 1.2 Part or Identifying Number (PIN). The PINs to be used for primer coatings acquired to this specif
3、ication are created as follows: M81904 - XXXXX - 1 Specification FED-STD-595 Identifier Color Number 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this section are specified in sections 3 and 4 of this specification. This section does not include documents cited in other sections of t
4、his specification or recommended for additional information or as examples. While every effort AMSC N/A FSC 8030 Comments, suggestions, or questions on this document should be addressed to: Commander, Naval Air Warfare Center Aircraft Division, Code 4L8000B120-3, Highway 547, Lakehurst, NJ 08733-510
5、0 or emailed to michael.sikoranavy.mil. Since contact information can change, you may want to verify the currency of this address information using the ASSIST Online database at https:/assist.daps.dla.mil. NOT MEASUREMENT SENSITIVE MIL-PRF-81904C(AS) 21 November 2011 SUPERSEDING MIL-C-81904B(AS) 31
6、May 1991 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-81904C(AS) 2 has been made to ensure the completeness of this list, document users are cautioned that they must meet all specified requirements of documents cited in sections 3 and 4 of
7、 this specification, whether or not they are listed. 2.2 Government documents. 2.2.1 Specifications, standards, and handbooks. The following specifications, standards, and handbooks form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents
8、 are those cited in the solicitation or contract. INTERNATIONAL STANDARDIZATION AGREEMENTS NORTH ATLANTIC TREATY ORGANIZATION (NATO) STANAG 4240 - Liquid Fuel/External Fire, Munition Test Procedures FEDERAL SPECIFICATION QQ-S-698 - Steel, Sheet and Strip, Low Carbon FEDERAL STANDARDS FED-STD-141 - P
9、aint, Varnish, Lacquer and Related Materials; Methods of Inspection, Sampling and Testing FED-STD-595 - Colors Used in Government Procurement/ FED-STD-595 Color Number 36375 (Medium Gray) COMMERCIAL ITEM DESCRIPTIONS A-A-2787 - Enamel, (Aerosol (Low VOC) A-A-59342 - Ethyl Alcohol (for Ordnance Use)
10、DEPARTMENT OF DEFENSE SPECIFICATIONS MIL-DTL-5624 - Turbine Fuel, Aviation, Grades JP-4 and JP-5 MIL-PRF-23699 - Lubricating Oil, Aircraft Turbine Engine, Synthetic Base, Nato Code Number O-156 MIL-DTL-83133 - Turbine Fuel, Aviation, Kerosene Type, JP-8 (NATO F-34), NATO F-35, and JP-8+100 (NATO F-3
11、7) DEPARTMENT OF DEFENSE STANDARD MIL-STD-810 - Environmental Engineering Considerations and Laboratory Tests Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-81904C(AS) 3 DEPARTMENT OF DEFENSE HANDBOOK MIL-HDBK-310 - Global Climatic Data for
12、Developing Military Products (Copies of these documents are available online at https:/assist.daps.dla.mil/quicksearch/or https:/assist.daps.dla.mil or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094.) 2.2.2 Other Government documents, drawi
13、ngs and publications. The following other Government documents, drawings and publications form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract. CODE OF FEDERAL REGULATIONS 49 CFR 171 178
14、 Transportation Hazardous Material Regulations (Copies of this document are available online at http:/ecfr.gpoaccess.gov or www.gpoaccess.gov/cfr/ or from the Superintendent of Documents, U.S. Government Printing Office, North Capital however the location shall ensure that flames impinge on the surf
15、ace of the sample. A data acquisition system, with a minimum sample rate of 1 sample per second (1 hertz), shall be used to record the time, temperature, and heat flux measurements. 4.6.4.1.2 Calibration. Prior to each TET, a calibration run shall be conducted using a blank plate with a Schmidt-Boel
16、ter heat flux gauge mounted in the center. The face of the heat flux gauge shall be in the same plane as the exposed surface of the blank plate. The average heat flux measured by the gauge shall be 17.6 BTU/ft2-sec 1.8 BTU/ft2-sec (200 kW/m2+20 kW/m2), once the gas flow has stabilized. The flow of g
17、as shall then be terminated, but the location of the torch shall be maintained. The heat flux gauge specified in 4.6.4.1.1 is in addition to the gauge used for calibration and shall also be in position during the calibration run the heat flux measured by this permanent heat flux gauge shall be monit
18、ored during the TET to confirm expected torch performance. 4.6.4.1.3 Test procedure. Upon completion of the calibration run and confirmation that the sample holder temperature is no more than 90 F (32 C), the blank Provided by IHSNot for ResaleNo reproduction or networking permitted without license
19、from IHS-,-,-MIL-PRF-81904C(AS) 12 plate shall be replaced with the test sample and the location of the propane torch from the calibration run shall be maintained. The maximum initial panel temperature, prior to fire testing, shall be 90 F (3 C). At time, T = 0, start the data acquisition system. At
20、 T = 30 seconds, the torch shall be lit. The time-temperature data for the panel back-side shall be noted and a note made of the time (in seconds) for any of the five thermocouples to reach 500 F (260 C), i.e. the first thermocouple to reach 500 F (260 C) for the thickness of the coating compound. 4
21、.6.4.1.4 Test results. The test results shall conform to 3.6.1 and the results shall be an average of three tests. 4.6.4.2 Color. The coating compound shall be prepared and applied to test panels in accordance with 4.5.1.1. The color and gloss of the coating compound shall meet the requirements of 3
22、.6.2, when tested in accordance with ASTM D1729. 4.6.4.3 Hardness. The coating compound shall be prepared and applied to test panels in accordance with 4.5.1.1. The Shore D hardness of the coating compound shall meet the requirements of 3.6.3, when tested in accordance with ASTM D2240. 4.6.4.4 Adhes
23、ion. The coating compound shall be prepared and applied to test panels in accordance with 4.5.1.1. An adhesion test shall be performed using a hammer and screwdriver (-inch to -inch blade width or equivalent) and the adhesion of the coating compound shall meet the requirements of 3.6.4. 4.6.4.5 Pull
24、-off adhesion. The coating compound shall be prepared and applied to three test panels in accordance with 4.5.1.2. The coating shall be tested using a 0.79 inch (20mm) dolly and the coating shall be scored down to base metal around the dolly prior to testing. The average of the three readings of pul
25、l-off strength of the coating compound shall meet the requirements of 3.6.5, when tested in accordance with ASTM D4541 Method E. 4.6.4.6 Paint adhesion. 4.6.4.6.1 Panel preparation. The coating compound shall be prepared and applied to test panels in accordance 4.5.1.1. After the coating compound is
26、 cured, enamel in accordance with A-A-2787 shall be applied to the coated panel in two coats. The enamel coating thickness shall be 1.0 to 1.5 mils. 4.6.4.6.2 Adhesion test. After the enamel is fully cured, the adhesion of the enamel to the coating compound shall be tested in accordance with ASTM D3
27、359, method B. Two sets of 6 cuts (1 mm apart) each shall be scribed 90 degrees to each other. Place tape over the grid area, and within 90 30 seconds of application, remove the tape by pulling it back on itself. Evaluate the enamel removal in accordance with ASTM D3359. The adhesion of the enamel s
28、hall meet the requirements of 3.6.6. 4.6.5 Resistance properties. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-81904C(AS) 13 4.6.5.1 Lubricating oil resistance. The coating compound shall be prepared and applied to test panels, in accordan
29、ce with 4.5.1.1. The test panels shall then be immersed in lubricating oil, conforming to MIL-PRF-23699, at a temperature of 250 4 F (121 2 C) for one minute. Eight hours after removal from the lubricating oil, the test panels when examined, shall meet the requirements of 3.7.1. 4.6.5.2 Ethanol resi
30、stance. The coating compound shall be prepared and applied to test panels, in accordance with 4.5.1.1. The test panels shall then be immersed in a solution of 95% ethanol, 5% water, conforming to A-A-59342, at room temperature for one minute. Eight hours after removal from the ethanol, the test pane
31、ls when examined, shall meet the requirements of 3.7.2. 4.6.5.3 Aviation fuel resistance. The coating compound shall be prepared and applied to test panels, in accordance with 4.5.1.1. The test panels shall then be immersed in aviation fuel, conforming to MIL-DTL-5624, at room temperature for one mi
32、nute. Eight hours after removal from the aviation fuel, the test panels when examined, shall meet the requirements of 3.7.3. 4.6.6 Impact resistance. Place one test panel prepared in accordance with 4.5.1.1 coating side up, over the hole of the cylindrical base of a Gardner Heavy-Duty Impact Tester
33、lG-1120. Determine the maximum impact resistance at which no failures occur. Repeat the test on the reverse side of another panel prepared in accordance with 4.5.1.1, with the coating side down. The test panels, when examined, shall meet the requirements of 3.7.4. 4.6.7 Humidity resistance. Two test
34、 panels shall be prepared as specified in 4.5.1.2. The coated test panels shall be tested for humidity resistance in accordance with ASTM D2247. Exposure time shall be 336 hours and exposure levels shall be 120 10 F (49 C) and 95 5 percent relative humidity. After removal from the humidity cabinet,
35、the coating compound on both panels shall be tested for hardness in accordance with 4.6.4.3. The coating shall be tested for pull-off adhesion strength on one panel in accordance with 4.6.4.5. The coating may be spot repaired after adhesion testing if coating is removed to the base metal. Both panel
36、s of the coating shall be tested for thermal efficiency changes in accordance with 4.6.4.1. The coating properties shall meet the requirements of 3.7.5. 4.6.8 Resistance to temperature shock. Two test panels shall be prepared in accordance with 4.5.1.2. The coating compound shall meet the requiremen
37、ts of 3.7.6, when tested in accordance with MIL-STD-810, Method 503.5, with the following exceptions: a. The internal hot-chamber temperature shall be maintained at 160 F (71 C) and 95 percent relative humidity. b. The Internal cold-chamber temperature shall be maintained at -65 F (-54 C). c. Panels
38、 shall be cycled every 24 hours, in lieu of 4 hours. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-81904C(AS) 14 d. The complete test period shall be 28 days. After removal from the test chamber, the coating compound shall be tested for har
39、dness on both panels in accordance with 4.6.4.3. The coating shall be tested for pull-off adhesion strength on one panel in accordance with 4.6.4.5. The coating may be spot repaired after adhesion testing if the coating is removed to the base metal. Both panels of the coating shall be tested for the
40、rmal efficiency change in accordance with 4.6.4.1. The coating properties shall meet the requirements of 3.7.6. 4.6.9 Weather resistance. Prepare three test panels in accordance with 4.5.1.2. One test panel shall be used as the control. The other two test panels shall be exposed for 500 hours in a X
41、enon-arc weatherometer (Atlas Electric Devices Company or equivalent as approved by the qualifying activity) that cycles between 102 minutes of light only and 18 minutes of light and water spray. The following conditions shall apply when testing in accordance with ASTM G155, type BH: a. Black body t
42、emperature in cabinet: 145 5 F (63 3 C). b. Relative humidity in cabinet: 50 5 percent. c. Intensity (spectral irradiance) of Xenon-arc: 0.35 0.01 Watts/meter (W/m) at a wavelength of 340 nm. d. Cabinet temperature: 108 5 F (42 3 C). After exposure, measure the color difference (E) value of the expo
43、sed panels and the control and examine the coating compound for conformance to 3.7.7. After removal from the test chamber, the coating compound shall be tested for hardness on both exposed panels in accordance with 4.6.4.3. The coating shall be tested for pull-off adhesion strength on one exposed pa
44、nel in accordance with 4.6.4.5. The coating may be spot repaired after adhesion testing if coating is removed to the base metal. Both panels of the coating shall be tested for thermal efficiency change in accordance with 4.6.4.1. The coating compound properties shall meet the requirements of 3.7.7.
45、4.6.10 Temperature and humidity cycling. The coating compound shall meet the requirements of 3.8.1 when tested to the 28-day temperature and humidity test of MIL-HDBK-310. For the 28-day temperature and humidity cycling test, the temperature range shall be -65 to +160 F (-54 to +71 C). 4.6.11 Fast c
46、ook-off. The coating compound shall meet the requirements of 3.8.2, when tested to the fast cook-off test in accordance with STANAG 4240, except as modified herein. In addition, the following shall apply: a. The quantity of fuel shall be sufficient to cause reaction of the ordnance or to ensure a 15
47、-minute fire (approximately a 2.5 inch (64 mm) depth of fuel), whichever is greater. Test fuel shall be JP-5 conforming to MIL-DTL-5624, or JP-8 conforming to MIL-DTL-83133. b. The test pit shall be a minimum of 24 feet by 24 feet (7.3 meters by 7. 3 meters) or a circular pit with a minimum diameter
48、 of 28 feet (8.5 meters). Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-81904C(AS) 15 c. Flame temperature shall reach l000 F (538 C) within 30 seconds after fire ignition, as measured by thermocouples in accordance with STANAG 4240. d. The
49、 bomb shall be suspended from its suspension lugs with its center 35 5.0 in. (0.89 0.13 meter) above the fuel. The bomb shall be placed with its longest axis along the diagonal of the test pit, when applicable, as shown on figure 1. e. The test shall not be performed when the wind velocity exceeds 5 knots (9.2 Km/hr). f. The test shall not b
