1、 _ AECIA PREN*wbObli 95 m LO12311 OQ10253 22T m Edition approved for publication 1995-12-15 AECMA STANDARD NORME AECMA AECMA NORM Comments should be sent within six months after the date of publication to AECMA Gulledelle 94 8-1 200 BRUXELLES prEN 6064 Edition P1 December 1995 PUBLISHED BY THE EUROP
2、EAN ASSOCIATION OF AEROSPACE INDUSTRIES (AECMA) Gulledelle 94 - 6-1 200 BRUXELLES - Tel. (32) 2 775 81 10 - Fax. (32) 2 775 81 11 ICs : Descriptors : ENGLISH VERSION Aerospace series Non-metallic materials Analysis of non-metallic materials (cured) for the determination of the extent of cure by Diff
3、erential Scanning Calorimetry (DSC) Srie arospatiale Luft- und Raumfahrt Matriaux non mtalliques Nichtmetallische Werkstoffe Analyse Enthalpique Diffrentielle (AED) des matriaux non mtalliques (polymriss) pour ia dtermination du degr de polymrisation Analyse von nichtmetallischen Werkstoffen (gehrte
4、t) zur Bestimmung des Vernetzungsgrades durch dynamische Differenzkalorimetrie (DSCI This “Aerospace Series“ Prestandard has been drawn up under the responsibility of AECMA (The European Association of Aerospace Industries). It is published on green paper for the needs of AECMA-Members. It has been
5、technically approved by the experts of the concerned Technical Committee following comment by the Member countries. Subsequent to the publication of this Prestandard, the technical content shall not be changed to an extent that interchangeability is affected, physically or functionally, without re-i
6、dentification of the standard. After examination and signature of the AECMA Standard Checking Centre INPSI and formal agreement of the Official Services of the Member countries it will be submitted as a draft European Standard to CEN (European Committee for Standardization) for formal vote. Nata - E
7、xtra copies can be supplied by B.N.A.E. - Technopolis 54 - 199, rue Jean-Jacques Rousseau - 921 38 ISSY-LES-MOULINEAUX CEDEX AIB/TFG Chairman Mr K. Schneider aecma 199 - AECMA PREN*bObY 95 9 303231l1 0030254 166 9 Page 2 prEN 6064 : 1995 Contents list 1 2 3 4 5 6 7 8 9 10 Scope Normative references
8、Definitions Principle of the method Designation of the method Apparatus Test specimen Procedure Presentation of the results Test report Annex A Equipment AECMA PREN*bOb4 75 W LOL23Ll 8010255 OT2 W Page 3 prEN 6064 : 1995 1 Scope This test method defines the procedure for the estimation of the extent
9、 of cure of certain non-metallic materials (e.g. preimpregnated and neat resin systems, adhesives) for aerospace use. The extent of cure is estimated by Differential Scanning Calorimetry (DSC) measurements of uncured (reference) and cured materials. Additional evidence on the extent of cure may be g
10、ained by combining results from this method with those obtained by other techniques. This standard does not give any directions necessary to meet the health and safety requirements. It is the responsibility of the user of this standard to adopt appropriate health and safety precautions. 2 Normative
11、references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any o
12、f these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. EN 2331 Aerospace Series Textile glass fibre preimpregnates Test methods for the determination of the resin an
13、d fibre content EN 2559 Aerospace Series Carbon fibre preimpregnates Test method for the determination of the resin and fibre content ) EN 2743 Aerospace Series Reinforced Plastics Standard procedures for conditioning prior to testing 4) 3 Definitions The determination of these parameters shall be a
14、greed upon between manufacturer and purchaser in case of non-ideal curves or different instrument types. 3.1 Curing reaction (see Figure 1) e is the heating rate, in degrees Celsius or Kelvin by minutes AH is the reaction enthalpy, in Joules by grams AH, is the reaction enthalpy corrected to 100 % r
15、esin content, in Joules by grams A-curve B-curve is the reference reaction curve for uncured material is the reaction curve for an already (semi-) cured sample 3.2 Calibration (see 6.6) Trn AH, is the melting temperature, in degrees Celsius or Kelvin is the enthalpy of fusion, in Joules by grams ” P
16、ublished as AECMA prestandard at the date of publication of this standard AECMA PREN*bOb4 95 m LO12311 00L025b T39 m Page 4 prEN 6064 : 1995 4 Principle of the method Differential Scanning Calorimetry (DSC) measures the temperatures and the heat flow associated with transitions in materials as a fun
17、ction of time and temperature. 5 Designation of the method The designation of the method used shall be drawn up according to the following example: Description block I Identity block Analysis of non-metallic materials Determination of the extent of cure by Differential Scanning Calorimetry (DSC) 1 E
18、N 6064 T Number of this standard I 6 Apparatus 6.1 The test shall be performed in a Dfferential $canning Calorimeter (DSC) capable of operating within the limits laid down in the test procedure. Instruments are given in the Annex A of this standard. If the DSC-apparatus of the manufacturer and the p
19、urchaser are different, a cross-check for comparison of the test results is necessary. 6.2 Balance with an accuracy of 0,Ol mg 6.3 Ancillary items such as sharp cutting knife and tweezers 6.4 Nitrogen (dry, min. 99/99 % purity) 6.5 Hollow punch with a diameter 1 mm e the diameter of the sample pan t
20、o cut out the required discs of adhesive, prepreg or laminate 6.6 Calibration The equipment shall be controlled using a pure indium sample to maintain a temperature accuracy to 2 0,5O C and a calorimetric precision within 1 % during test. Periodically the temperature and cell constant shall be calib
21、rated using pure samples of the materials specified in Table 1 (type and values according to DSC manufacturer recommendations). Temperature calibration shall be performed using two or preferably three materials over the temperature range of interest. The heating rate for calibration shall be the sam
22、e as used in the subsequent experiments .e. loo C/min for standard operation (see 8). AECMA PREN*bOb4 95 L0123LL 0010257 975 D Page 5 prEN 6064 : 1995 The instrument calibration shall be performed using the same sample pan type, purge/purge rate and equivalent thermal mass samples as will be used in
23、 subsequent experiments. The base line and the cell shall be checked periodically (interval to be agreed between the parties). The base line drift for a pair of empty pans or pans containing an inert substance shall not exceed 1 ,O mW over the range -50 OC to 300 OC. 7 Test specimens 7.1 Preparation
24、 Test specimens shall be selected in accordance with the sampling procedure defined in the Material Specifi- cation. For the A-curve uncured samples, for the B-curve (semi-) cured samples shall be taken. Each sample shall comprise approximately the equivalent of 7 to 10 mg of neat resin (for example
25、 20 mg of prepreg). In case of extreme enthalpy of reaction the sample size of the material may be adjusted to achieve acceptable curves in the diagram. The sample mass shall be determined to 0,Ol mg (see 6.2). For quantitative measurements it is necessary to correct the AH to 1 O0 % resin content (
26、AH,oo), the resin content shall be determined using the test methods of 7.1.1 or 7.1.2. A minimum of two test specimens shall be used for standard operations (e.9. release testing). For determination of standard deviations a minimum of six specimens are necessary (e.g. qualification pro- grams). 7.1
27、.1 Determination of actual fibre / resin content Carbon composite : according to EN 2559 Glass composite according to EN 2331 Aramid composite : according to EN 2559 but using HNO, / DMSO If an insoluble filler (such as SiO,) is present, it shall be determined separately (after the removal of the fi
28、bre) by Centrifuging and its mass added to the reinforcement content. 7.1.2 Determination of actual carrier I resin content for adhesives (uncured) Usual extraction technique: use ultrasonic bath and appropriate solvent such as DMF, DMSO, NMP. Determine the carrier weight after twice flushing with s
29、olvents such as Acetone or MEK and thorough drying. If an insoluble filler is present, it shall be determined separately (after the removal of the carrier) by centrifuging and its mass added to the reinforcement content. Actual resin content: mresin = mdhesive - mcarrier 7.2 Conditioning 7.2.1 Condi
30、tioning of material stored at ambient temperature For material stored at ambient temperature, the amount of material required for testing shall be sampled and conditioned in the standard atmosphere (defined in EN 2743) for a minimum of 2 h, unless otherwise specified. AECMA PRENubOb4 95 LOlI23LL OOL
31、0258 801 Page 6 prEN 6064 : 1995 7.2.2 Conditioning of material stored below ambient temperature For material stored at temperatures lower than ambient temperature, the material, suitably packed in an airtight bag (containing a suitable desiccant) to prevent moisture pick-up, shall be allowed to rea
32、ch ambient temperature over a period of time according to the mass of the package. The actual time shall be recorded in the report. When the material has reached ambient temperature, the amount (together with the release film on it) required for testing shall be sampled and conditioned in the standa
33、rd atmosphere (defined in EN 27431 for a minimum of 2 h, unless otherwise specified. 7.2.3 Standard atmosphere for testing The test equipment shall be at (23 f 2)O C and (50 f 5) % relative humidity (EN 2743 B conditions) The actual test environment is controlled inside the equipment. 7.2.4 Time int
34、erval between conditioning and testing After conditioning, the test shall be carried out within 6 h, unless otherwise specified, the specimen being kept in the standard atmosphere until the test is carried out. 8 Procedure 8.1 A-curve The sample shall be placed in a sample pan ensuring that it is in
35、 good thermal contact with the pan. The lid shall be firmly crimped on but not hermetically sealed to avoid pressure increase. Place the two pans containing the sample and the reference into the DSC cell (see 6.1 II close the system and purge with pure dry nitrogen (preferred flow 20 to 30 ml/min).
36、The following test conditions shall apply: - reference sample empty sample pan and lid (if necessary containing inert material for example alumina) - atmosphere Nitrogen (see 6.4) - test start temperature room temperature - test end temperature After the end of the region of interest - heating rate
37、1 Oo C/min standard, unless otherwise specified - a record of heat flow dq/dt) versus temperature shall be obtained between test start and test end. 8.2 B-curve Follow 8.1 I but use samples cured in an DSC pan eitherusing the standard curing cycle or the cycle to be investigated. For investigation o
38、f manufactured parts or laminates the samples shall be taken from the item concerned. AECIA PRENabOb4 95 LOl123l1l1 0010259 748 = Page 7 prEN 6064 : 1995 8.3 Extent of cure u The value of the extent of cure o is determined by the following formula * 100 %I AHA - AH, a= AHA The correction to 100% res
39、in content is done by using the figures determined in 7.1.1 and 7.1.2, (I (1 00) is determined with the corrected enthalpies. 9 Presentation of the results The following features from the reaction exotherm curve shall be determined as shown in figure 1. In a non- ideal situation an agreement between
40、 the parties shall be obtained. 9.1 AHA - reaction enthalphy, A-curve AtiAllooi) - reaction enthalphy, A-curve corrected to 100 % resin content 9.2 AH, - reaction enthalphy, B-curve - reaction enthalphy, B-curve corrected to 1 O0 % resin content (AHBilooi) 9.3 CI - extent of cure (,lOOJ - extent of
41、cure corrected to 100 % resin content 10 Test report The test report shall refer to this standard and include the following: 1 O. 1 Complete identification of the material tested, including manufacturers name, designation, batch number etc. 10.2 All details about the preparation of the specimens inc
42、luding conditioning (time for material to reach room temperature). 10.3 Specimen mass and, if required, resin content and method of determination. 10.4 Date of test, facility and identification of individuals performing the tests. 10.5 Equipment and test parameters used including temperature range a
43、nd heating rate and specific cure conditions. 10.7 Any incident which may have affected the results and any deviation from this standard. AECMA PREN*bOb4 95 LOL23LL OOLD2bO 4bT Page 8 prEN 6064 : 1995 The use of alternative baselines are acceptable if agreed between the parties. Points A and B may b
44、e determined from a derivative plot. A B AH is the lowest point before increase to peak is the lowest point after decrease from peak is the area under the curve between point A and B, divided by the mass of the sample. Figure 1 : Evaluation of the reaction exotherm curve (idealized) AECMA PREN*6064
45、95 LOL23LL 001026L 3Tb Material H2O In Sn Pb Page 9 prEN 6064 : 1995 T, (“ CI AH, (J/gI oro 156,6 28,59 231,9 60,58 327,5 Table 1 : Melting temperatures and enthalpies of fusion of calibration materials Cyclohexane 6,5 I Zn I 41 9,5 I Page 10 prEN 6064 : 1995 Annex A : Equipment The following equipm
46、ent may be used: A.l Mettler TA 3000 / TA 21 O0 - DSC 20 / DSC 30 Mettler Instrument Corporation Box 71, Hightstown N.J. 08520 U.S.A. A.2 DuPont 9900 TA Systems Silver Side Road Wilmington, DE 19898 U.S.A. A.3 Perkin Elmer DSC 2 / DSC 4 / DSC 7 Perkin Elmer Co., Analytical Instruments Main Avenue (MS-12) Norwalk CT 06856 U.S.A.
