1、MIL-G-473LbA 93 m 99999Ob 0528538 5 m INCH-POUND MIL-G-47316A (MI) 26 May 1992 SUPERSEDING MIL-G-47316 (MI) 14 August 1987 MILITARY SPECIFICATION GRAPHITE, MOLDED, FOR HIGH TEMPERATURE APPLICATIONS This specification is approved for use by the U.S. Army Missile Command, Department of the Army, and i
2、s available for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification defines the requirements of one .type of molded graphite for high temperature applications. 1.2 Classification. The molded graphite is classified using the following styles: Style
3、 A - rectangular blocks Style B - cylindrical billets. Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Commander, U.S. Army Missile Command, ATTN: AMSMI-RD-SE-TD-ST, Redstone Arsenal, AL 35898-5
4、270 by using the Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter. AMSC N/A FSC 9390 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Provided by IHSNot for ResaleNo reproduction or networking permitted w
5、ithout license from IHS-,-,-MIL-G-473LbA 93 m 9999906 0528539 7 m c . =. MIL-G-47316A (MI) 2. APPLICABLE DOCUMENTS 2.1 Government documents. 2.1.1 Specifications, standards, and handbooks. The following specifications, standards, and handbooks form a part of this document to.the extent specified her
6、ein. Unless otherwise specified, the issues of these documents are those listed in the issue of the Department of Defense Index of Specifications and Standards (DODISS) and supplement thereto, cited in the solicitation (see 6.2). STANDARDS MILITARY MIL-STD-129 - Marking for Shipment and Storage MIL-
7、STD-130 - Identification Marking of US Military Property (Unless otherwise indicated, copies of the federal and military specifications, standards, and handbooks are available from the Standardization Documents Order Desk, Bldg. 4D, 700 Robbins Ave., Philadelphia, PA 19111-5094.) 2.2 Non-Government
8、publications. The following documents form a part of this document to the extent specified herein. Unless otherwise specified, the issues of the documents which are DoD adopted are those listed in the issue of the DODISS cited in the solicitation. Unless otherwise specified, the issues of documents
9、not listed in the DODISS are the issues of the documents cited in the solicitation (see 6.2). AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM) ASTM C 651 - Flexural Strength of Manufactured Carbon and Graphite Articles Using Four-Point Loading at Room Temperature, Standard Test Method for Practice
10、for ASTM D 3951 - Commercial Packaging, Standard (Application for copies should be addressed to the American Society for Testing and Materials, 1916 Race Street, Philadelphia, PA 19103.) 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4 c MIL-G-4 7
11、 31 6A (MI ) (Non-Government standards and other publications are normally available from the organizations that prepare or distribute the documents. These documents also may be available in or through libraries or other informational services.) 2.3 Order of precedence. In the event of- a conflict b
12、etween the text of this document and the references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 First article. When specified (see 6.21, a sa
13、mple shall be subjected to first article inspection (see 6.3) in accordance with 4.4. 3.2 Material. The material shall be graphite formed by the molding process from petroleum coke having a particle size not greater than 0.006 inch combined with coal tar pitch (see 4.7). blocks and cylindrical bille
14、ts shall be as specified in the contract or order (see 6.2) . 3.2.1 Dimensions. The dimensions of the graphite rectangular 3.3 ProDerties. -A - 3.3.1 Apparent density. Apparent density of the graphite shall be not greater than 0.065 nor less than 0.060 ounce per 0.061 - cubic inch (see 4.6.2). 3.3.2
15、 Specific resistance. Specific resistance of the graphite shall be not greater than 13.0 x ohm - centimeter (ohm - cm) with the grain and not greater than 17.0 x ohm - cm across the grain (see 4.6.3). 5 3.3.3 Flexural strength. Flexural strength of the graphit shall be not less than 2600 pounds forc
16、e per square inch (lbf/in ) with the grain and not less than 2400 lbf/in2 across the grain (see 4.6.4). 3.3.4 Ash content. Ash content of the graphite shall be not greater than 0.25 percent (see 4.6.5). 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,
17、-,-MIL-G-4731bA 93 m 99999Ob 0528543 5 m * + MIL-G-47 31 6A (MI) 3.4 Marking. Each block or billet of graphite specified herein shall be permanently marked in accordance with MIL-STD-130 with the following information: a. Title, number and date of this specification b. Part number c. Suppliers name,
18、 address, and material designation. d. Purchase order number e. Lot number f. Weight and size of block or billet. 3.4.1 Identification. Rectangular blocks and cylindrical billets shall be color-coded red on each end. The with-grain direction shall be marked with an arrow in figure 1. accordance with
19、 c TYPICAL o SPECIMEN WITH GRAIN NOTES : 1. -Denotes with-grain direction 2. Specimen A with grain 3. Specimen B across grain FIGURE 1. Graphite block and billet test specimens. 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-G-47316A (MI) 3.5
20、Workmanship. The graphite shall be manufactured to assure uniform material free from visual cracks or other defects that would prevent its use for the purpose intended. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for inspection. Unless otherwise specified in the contract or purchase order, th
21、e contractor is responsible for the performance of all inspection requirements (examinations and tests) as specified herein. Except as otherwise specified in the contract or purchase order, the contractor may use his own or any other facilities suitable for the performance of the inspection requirem
22、ents specified herein, unless disapproved by the Government. The Government reserves the right to perform any of the inspections set forth in this specification where such inspections are deemed necessary to ensure supplies and services conform to prescribed requirements. 4.1.1 Responsibility for co
23、mpliance. All items shall meet all requirements of sections 3-and 5. The inspection set forth in this specification shall become a part of the contractors overall inspection system or quality program. inspection requirements in the specification shall not relieve the contractor of the responsibility
24、 of ensuring that all products or supplies submitted to the Government for acceptance comply with all requirements of the contract. Sampling inspection, as part of manufacturing operations, is an acceptable practice to ascertain conformance to requirements, however, this does not authorize submissio
25、n of known defective material, either indicated or actual, nor does it commit the Government to accept defective material. The absence of any 4.2 Classification of inspections. The inspection requirements specified herein are classified as follows: a. First article inspection (see 4.4). b. Quality c
26、onformance inspection (see 4.5). 4.3 Inspection conditions. Unless otherwise specified, all inspections shall be performed in accordance with the test conditions specified in applicable test methods documents and as specified herein. 4.3.1 Ambient conditions. Unless otherwise specified, all inspecti
27、ons and tests shall be conducted at room temperature 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-G-4731bA 93 9979906 0528543 9 MIL-G-47316A (MI) between 20.9 and 31.9 Celsius (C) and at standard atmospheric pressure. 4.4 First article inspe
28、ction. When specified in the contract or order (see 6.2), a first article sample consisting of ten blocks or billets shall be subjected to first article inspection as specified in table I. Subsequent units shall not be considered for acceptance until Government approval of the first article sample h
29、as been obtained (see 3.1 and 4.2). TABLE I. First article inspection. Inspection Apparent density Specific resistance Flexural strength Ash content Certification Workmanship Requirement paragraph 3.3.1 3.3.2 3.3.3 3.3.4 3.2 3.4 Test paragraph 4.6.2 4.6.3 4.6.4 4.6.5 4.7 4.6.1 4.5 Quality conformanc
30、e inspection. Quality conformance inspections shall be as specified in table II (see 4.2). TABLE II. Quality conformance inspection. Requirement Test Inspection paragraph paragraph Workmanship Apparent density 3.4 3.3.1 4.6.1 4.6.2 4.5.1 Lot formation. The sample selected shall consist of a random s
31、election of 10 percent of the lot but not less than one block or billet, as specified in the contract or order (see 6.2). A lot shall consist of graphite of one shape produced by one manufacturer, in one unchanged process, using the same materials and methods and offered for acceptance at one time.
32、The lot size shall be not greater than 100 blocks or billets. 4.5.2 Sampling. The sample selected shall represent only that quantity of units from which the sample was drawn and shall not be construed to represent any prior or subsequent quantities 6 Provided by IHSNot for ResaleNo reproduction or n
33、etworking permitted without license from IHS-,-,-MIL-G-4731bA 93 W 99999Ob 0528544 O W - Inspection MIL-G-4 7 3 16A (MI) Requirement Test paragraph paragraph presented for inspection. The sample shall be subjected to inspections specified in tables II and III. Specific resistance Flexural strength A
34、sh content 3.3.2 3.3.3 3.3.4 4.6.3 4.6.4 4.6.5 4.6 Methods of inspection. 4.6.1 Examination. Unless otherwise specified, samples shall be visually examined with an unaided eye to determine conformance to 3.4. 4.6.2 Apparent density. Apparent density shall be determined in accordance with the followi
35、ng to determine conformance to 3.3.1: a. b. C. d. e. Measure each dimension of the full block or billet to the nearest 0.03 inch in three or more places. Average each dimension and calculate the volume of the block or billet based on the average dimensions. Weigh the block or billet to the nearest 0
36、.25 pound. Calculate apparent density as follows: Apparent density, lbs/in3 = - M V Where: M = weight of sample, pounds V = volume of sample, cubic inches Report the apparent density of each block or billet in the lot. 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without li
37、cense from IHS-,-,-MIL-G-4731bA 93 W 99999Ob 0528545 2 W MIL-G-47316A (MI) 4.6.3 Specific resistance. Specific resistance shall be determined in accordance with the following to determine conformance to a. 3.3.2: Assemble specific resistance testing apparatus as shown in figure 2. 1 TBLACK “7 LSPECI
38、MEN7 l-f n II I II Y ELLOW GREEN I II RESISTANCE APPARATUS I -. - - Lo RED -14 v SHUNT 0 Y ELLOW 40 (low) -GREEN I a 4 BLACK CFURRENT, DRY CELL BATTERIES - ?% DPDT (CENTER OFF) TOGGLE SWITCH RED* * BLACK POTENT IOMETER ELECTRICAL SCHEMATIC FIGURE 2. Specific resistance test arrangement. b. Balance t
39、he potentiometer according to the manufacturers instructions. c. Use specimens A for with-the-grain determinations and specimens B for across-the-grain determinations (see figure 1). 8 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-G-47316A (MI)
40、 d. Place a weight of approximately five pounds on the e. Determine the current passing through the test center of the specimen to assure contact of the potential points. specimen. Determine the voltage drop across the potential points. f. g. Calculate specific resistance as follows: Specific resist
41、ance, ohm-cm = E x A IXL Where : A = cross-sectional area, square cm L = length of conductor, cm E = potential difference, volts I = current, amperes h. Report the average of the results for specimens A (with grain) and the average for specimens B (across grain) for each block or billet. be determin
42、ed in accordance with ASTM C 651 and the following: 4,.6.4 Flexural strength. Flexural strength (see 3.3.3) shall a. Optional construction of the loading head and bed of the testing machine shall be permissible provided the distances between supports and points of load application are maintained and
43、 the application of load and directions of reactions are not affected. b. The contact surface of each load applying and load receiving block shall be cylindrical or have a 0.03 inch wide flat surface. (No sharp edges are permitted. ) c. Only specimens that fracture within the middle third of the spa
44、n length shall be considered valid tests. d. Use specimens A for with-the-grain determinations and specimens B for across-the-grain determinations. 9 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-_- MIL-G-4731bA 93 999990b 0528547 b M I MIL-G-47 3
45、16A (MI) e. Report the average of the results with-the-grain and the average across-the-grain for each sample block or billet. 4.6.5 Ash content. Ash content shall be determined in accordance with the following using composited pieces of test specimens from the flexural strength test to determine co
46、nformance to 3.3.4: a. b. C. d. e. f. g. h. i. Weigh a sample of approximately 10 g, to the nearest milligram (mg), into a tared 100 cubic centimeter (cc) platinum or porcelain crucible. Place the weighed sample in a muffle furnace and heat the sample to a temperature of 800 to 900 Celsius (C) for n
47、ot less than 24 hours. To prevent ash fusion, temperature shall be not greater than 90 ooc . Allow the crucible and sample to cool to room temperature in a desiccator. Examine the residue for traces of carbon. If carbon is present, continue ignition until ashing is complete. Transfer the sample resi
48、due to a desiccator and allow to stand for not less than 1 hour before weighing. Weigh the residue to the nearest 0.1 mg. When there is no further visual evidence of carbon, repeat the ignition for 1 hour periods at 800 to 900“ C until a constant weight is obtained. Calculate ash content as follows:
49、 x 100 Ash content, percent = ash weight sample weight Report the average of not less than two determinations for each sample block or billet. 10 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-G-473LbA 93 99999Ob 0528548 8 9 _ W ii MIL-G-4 7 3 16A (MI ) 4.7 Certification. The supplier shall c
