1、M I L-Y-87125A CUSAFI 27 July 1979 SUPERSEDING MIL-Y-87125 (USAF) 7 APRIL i978 MILITARY SPECIFICATION YARN I GRAPH I TE ? 1000/3000 F I LAMENTS s approved for use by Air Force Materials Laboratory, This specification Department of the A r Force, and is available for use by all Departments and Agenci
2、es of the Department of Defense. 1. SCOPE 1.1 Scope. This specification establishes the requirements and quality assurance provisions for continuous fi lament high modulus graphite yarn derived from pyrolyzed polyacrylonitrile filaments. 1.2 Classification. The yarn consists.of 1000 filament or 3000
3、 filament material exhibiting and minimum single fiber tensile strength of 360 X 103 psi (2480 MPa) and minimum single fiber tensile inodulus of 52 X lo6 psi (359 GPa). Type I 1000 fi laments Type I I 3000 fi laments 2. APPL I CABLE DOCUMENTS 2.1 on the date of invitation for bids or request for. pr
4、oposal? form a part of this specification to the extent specified herein. Issues of documents. The following documents of the issue in effect SPECIFICATIONS MILITARY MI L-C-45662 - Calibration System Requirements Beneficial comments (recommendations, additions, deketions) and any , pertinent data wh
5、ich may be of use in improving this docment should be addressed to: AFML/MXA, WPAFB, O. 45433 by using the self-addressed Standardizatton Document Improvement Proposal (DD Form 1426) appearing at the end of this document 6r by letter. : -I Provided by IHSNot for ResaleNo reproduction or networking p
6、ermitted without license from IHS-,-,-STANDARDS . Mi 1 itary MIL-STD-105 - Sampling Procedures and Tables for Inspection by Attributes MIL-STD-129 - Marking for Shipment and Storage MIL-STD-130 - Identification Marking of U.S. Military Property MIL-STD-794 - Parts and Equipment, Procedures for Packa
7、ging and Packing of (Copies of specifications, standards, drawings, and pub1 icationc required by Contractors in connection with specific procurement functions should be obtained from the procuring activity or as directed by the Contracting Off i Cer, ) 2.2 Other publications, The following document
8、s form a part of this spectfication to. the extent specified herein. the issue in effect on the date of invitation for bids or request for proposal shall apply. Unless otherwise indicated, AMER I CAN SOC I ETY FOR TEST I NG AND MATERIALS (ASTM) ASTM 0891 - Specific Gravity of Industrial Aromatic Hyd
9、rocarbon and Related Materials ASTM D1423 - Twist in Yarns by the Direct-Counting Method ASTM D3373 - Tensi le Strength and,Youngs Modulus for High- Modulus Single-Filament Materials (Application for copies should be addressed to American Society for Testing and Materials, i916 Race Street, Philadel
10、phia, PA 19103). SOC I ETY OF AUTOMOTIVE ENGINEERS (AMS) AMS 3892 - Fibers, Graphite Tow and Yarn - for Structural Composites (Applications for Copies should be addressed to Society of Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale, Pennsylvan (Technical Society and Technical associa
11、tion specifications and are generally available for reference from libraries. They are distributed among technical groups and using Federal Agencies.) 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-Y-7125A 3 M 777770h 0411305 O M mum uns i zed
12、 mum MI L-Y-87125A(USAF) .O66 99.6 3. REQUIREMENTS 3.1 and wound in accordance -with the proposed product ion methods shall be subjected to preproduction tests prior to the beginning of production. The yarn shall meet the requirements of 3.2, 3.3, 3.4 and 3.5. Preproduction. Three one pound spools o
13、f yarn which are processed . 3.2 Product characteristics. The yarn shall conform to the following requ i remen t s. 3.2.1 Physical properties. The physical properties of the yarn shall conform to the requirements of Table I. TABLE I. Physical characteristics. I Type i !length -per un it we ght 12,86
14、0 to 15,000 600 tQ 700 I lot average m/Kg Denier I I Density, gm/cm3, minimum I 1.82 lbs/in3, min -I Carbon con tent , .percent, min Type I I 4240 to 4690 1920 to 2120 1.82 .O66 99.6 3.2.2 Construction. Yarn shall be formed from parallel lays of multi- filament graphite fibers lightly stranded or tw
15、isted together with either approximately one-half turn per inch or 25 mm, or not more than one turn per foot or 300 mm, into one or more plies. If two or more plies, the final yarn shall be manufactured by twisting the plies together in a direction opposite to the twist direction of the individual p
16、lies. twists used to make the final yarn shall be approximately the same as the number of twists used in making the individual plies. There shall be no residual rotation. 3.2.3 Splicing. When aplicing is necessary to achieve required package size, the yarn shall be spliced by an overlap joint made w
17、ith a compatible : ! or 750 m. There shall be no unbonded overlap lengths (tails). The splice E i, The number of -resin. The minimum distance between splices shall be 500.feet or 150 m I and the average distance between splices shall be not less than 2500 feet strength shall be capable of withstandi
18、ng a 50 gram load as measured on the dry fiber bundle. A splice shall be not more than 3 inches or 75 mm .long and shall be capable of being drawn through a slot two times as wide as the nominal fiber bundle diameter. + . x, 3 Provided by IHSNot for ResaleNo reproduction or networking permitted with
19、out license from IHS-,-,-Ml L-Y-87 125A(USAF) 3.2.4 Sizing; Polyvinyl alcohol sizing.content shall be 0.4% to 1.5% for 1000 filament yarn E 0.4% to 1.2%for 3000 filament yarn. shall be no accumulation of sizing in any local areas so as to form bubbles or drops on the yarn surface or to cause matting
20、 of the fiber bundle. There 3.2.5 Minimum iength. The yarn shall be manufacturedor spliced into continuous lengths corresponding to standard size packages, such as 1, 2- and 4 pounds (0.45, 0.91, and 1.81 kg) as ordered by the procuring gency . 3.2.6 not contain loose plies, cuts, tears, chafes or s
21、lips, excessive accumu- Surface condition, As unwound from its holder, the yarn shall lations of broken fibers or fuzz balls. and its surface straight and centered on the holder core. It shall not break or tear during unwinding. 3.3 Mechanical properties. The mechanical properties of the yarn shall
22、meet the requirements of Table I I. The yarn shall be tightly wound TABLE li. Tensile properties of 1000 and.3000 yarn filaments. I Single fi lament I TENSILE STRENGTH Lot Avg., Min PSI X 103 MPa TENS I LE MODULUS Lot Avg., tin PSI x 10 G Pa 36 O 2480 52 359 Yarn . 320 22 10 50 3 45 3.3.1 Tensile pr
23、operties. Tensile strength and modulus testing may be conducted on either single filaments or on yarn bundles. 10 per cent of the lot average value shall be below the minimum lot average specified in Table 1 I. 3.4 Identification and marking. Identification and marking shall be in accordance with MI
24、L-STD-130. using a label affixed to the inside of one end of the yarn holder. information on the label shall be in permanent ink. contain the following information: No more than Each spool of yarn shall be identified The The label shall Provided by IHSNot for ResaleNo reproduction or networking perm
25、itted without license from IHS-,-,-MI L-Y-87125A(USAF) a. Manufacturers type, grade, and. finish . b. Lot number of yarn and date- of manufacture c. Twist d. Net weight of holder e. Purchase order number. 3.5 Workmanship. The graphite yarn shall be sized and wound on its holder in a careful and work
26、manlike manner. Particular attention shall be given to assuring that the yarn contains the proper number of filaments, the sizing is uniform and contains no bubbles, the splices are properly bonded and cured, and the yarn surface does not contain nicks, cuts, or fuzz balls. 4. QUALITY ASSURANCE PROV
27、 I SI ONS other speci f cur ng forth assure 4.1 Responsibility for inspeetion. Unless otherwise specified in the contract or purchase order, the supplier is responsible for the performance of al 1 inspection requi rements as speci f ied herein. specified in the contract or order, the supplier may us
28、e his own or any Except as otherw-ice aci I i ties sui table for the performance of the inspection requi rements ed herein, unless disapproved by the procuring activity. The pro- activity reserves the right to perform any of the inspections set n the specification where such inspections are deemed n
29、ecessary to that suppl es and services conform to prescribed requi rements. 4.2 Classification of inspections. The inspection requirements specified herein are classified as follows: a. Preproduction testing (see 4.3). b. Qual i ty conformance inspection (See 4.4). 4.3 Preproduction tests. preproduc
30、tion yarn to the following tests. Subject each of the three one pound spools of Verify compliance with 3. a. b. d. e. f, 9- h. i. j. k. 1. C. Length/unit weight (4.6.1)- Densi ty (4.6.2)- Carbon content (4.6.3)- Construct i on (4.6.4) Splicing (4.6.5). Sizing (4.6.6)- Surface condi tion (4.6.7). Ten
31、sile strength E Modulus (4.6.5). Identification 4.4.1.1 Lot. A lot shall consist of all araphite fibers manufactured and same batches of .a - gath,ered into a yarn in a continuous operati raw materi al s. shall be in re in Table I and Level of 10 as specified in MIL-STD-105. Test specimens shall be
32、taken at random throuqh- 4.4.1 .2 Sampl ing. Sampl ing for acceptance accordance with, special inspection level C-1 normal inspect ion. Table I IA with an acceptab ln from th nspect i on sample s e Quality out each lot. the production lot size, inspect each unit. 4.4.1.2.1 Inspection unit. Unless ot
33、herwise specified, an inspection unit is defined as each holder (see5.1.1) of continuous length yarn, but shall not exceed 5.0 lb. or 2.25 kg of material. If number of inspection units to be sampled equals or exceeds 4.5 Test conditions. Unless otherwise specified tests shall be conducted at an atmo
34、spheric pressure of 28-32 inches of mercury, a temperature of 72 to 80F (22 to 26C), and a relative humidity of 40 to 60 percent. 4.5.1 Measurements. All measurements shall be taken with instruments whose accuracy has been verified in accordance with MIL-C-45662. 4.6 Test methods. 4.6.1 Length per u
35、nit weight. The following procedure shal determine length per unit weight of yarn. a. Measure a 3 meter length of yarn to the nearest m b, Weigh the yarn to the nearest 10 milligrams. c. Calculate the length per unit weight as follows: 6 Provided by IHSNot for ResaleNo reproduction or networking per
36、mitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MI L-Y-87125A(UCAF) 4.6.3.2.2 Instrument conditioning. At the beginning of each days work, the instrument must be conditioned. This is accomplished by repeated combus
37、tion of cyclohexanone-2,4-dini trophenylhydrazone (2 ,bio) until the N2C02 and H20 peaks are well defined. The amount of 2,4-D need only be estimated (rather. than weighed) for the conditioning step. Usually, no more than three combustions, are necessary. 4.6.3.3 We i gh i ng procedure. 4.6.3.3.1 Ca
38、libration of balance. a. Move the range switch to the extreme. clockwise position. b. Rotate the range switch counterclockwise two click stops (x 10 range). c. Using tweezers, place a sample boat on each stirrup. d. Move the main switch to the ZERO position. e. Turn the BALANCE control to the full c
39、ounterclockwise position. f, Move the coarse level until the beam is just slightly below the reference 1 ines (viewed through the i 1 luminated lens). g. Close the door and precisely align the beam and the reference lines using the BALANCE control. h. Depress the meter switch and hold it down while
40、rotating the ZERO control to precisely align the null meter needle with the center mark. Use the mirror to be certain that parallax does not produce a false reading. Release the meter switch when properly nulled. Depress momentarily to note any slight deflection. Null again if there is. i. Turn the
41、BALANCE control clockwise to the sixth click position. Using tweezers, place the 10 mg calibrating weight on the left sample boat. j. Close the sliding glass door. k, Turn the main switch to the CAL pos 1. Align the beam with the reference 1 BALANCE Con t ro 1 coun te rc 1 ockw i se tion. nec by sto
42、wly rotating the m. Hold the meter switch depressed while nulling the meter with the CALIBRATE Control. Release the meter switch when properly nul led. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-M IL-Y-87125A(USAF) n. Move the main switch to the
43、 ZERO position. o. Open the sliding door and remove the calibrating weight. p. Rotate the range switch to the X1 position (fully clockwise). 4.6.3.3.2 Obtaining sample weighti a. Rotate the BALANCE control to the extreme counterclockwise position (past al 1 six ci ick stops). b. Rotate the BALANCE c
44、ontrol slowly clockwise until the beam aligns with the reference line. Do not rotate the BALANCE control to a point where it passes the first click stop. If the beam cannot be aligned without going past the first clock stop, return the BALANCE control to the extreme counter- clockw.ise position and
45、adjust the coarse lever until the beam approaches the reference lines. At this point, return to the BALANCE control for the precise final alignment. c. Depress the meter switch and hold while nulling the meter with the ZERO con t ro 1 . d. e. Open the door and carefully tap sample from the spatula i
46、nto the left Rotate the BALANCE to the fourth click position. sample boat until the beam approaches the reference lines. High boiling, (nonvolatile) liquid samples can be introduced into the sample boat by means of a micro pipette or dropper. Volatile liquids must be first loaded into capillary tube
47、s as described in the FEM Instruction Manual supplied with the instrument. f. g. Slowly turn the BALANCE control counterclockwise (fine range) to Close the door and move the main switch to the READ position. precisely align the beam with the reference lines. h. Hold meter switch depressed while null
48、ing meter using the weight dial. The weight of sample can be read directly from the dial in decimals of mg., such as, 6198 = 0.6198 mg. remove same sample; if below 0.6000 mg, add sample. 4.6.3.4 When perfectly nulled, release meter switch. i. NOTE: if reading is above 0.8000 mg, . Preparation of sa
49、mple for combustion. a. Posi.tion one of the combustion rod assemblies on the rod hblder and slide the retaining nuts to within 2 inches of the rod end. The small retaining nut must not be tightened into thelarge nut. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-M I L-Y-87125A (USAF) b. Using tweezers, remove the weighed sample from the balance and pla
