1、AECMA PREN+bOYL 95 = 10L231L 001002Y 667 - AECMA STANDARD prEN 6041 NORME AECMA Edition P1 AECMA NORM November 1995 PUBLISHED BY THE EUROPEAN ASSOCIATION OF AEROSPACE INDUSTRIES (AECMA) Gulledelle 94 - 6-1200 BRUXELLES - Tel. (32) 2 775 81 10 - Fax. (32) 2 775 81 11 ICs : Descriptors : ENGLISH VERSI
2、ON Aerospace series Non-metallic materials Test method Analysis of non-metallic materials (uncured) by Differential Scanning Calorimetry (DSC) Srie arospatiale Matriaux non mtalliques Mthode dessai Analyse Enthalpique Diffrentielle (- .ED) des matriaux non mtalliques (non polymriss) Luft- und Raumfa
3、hrt Nichtmetallische Werkstoffe Prfverfahren Analyse von nichtmetallischen Werkstoffen (unpolimerisiert) mittels dynamischer Differenzkalorimetrie (DSC) This “Aerospace Series Prestandard has been drawn up under the responsibility of AECMA (The European Association of Aerospace Industries). It is pu
4、blished on green paper for the needs of AECMA-Members. It has been 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 inter
5、changeability is affected, physically or functionally, without re-identification 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
6、 (European Committee for Standardization) for formal vote. Nota - Extra copies can be supplied by B.N.A.E. - Technopolis 54 - 199, rue Jean-Jacques Rousseau - 921 38 ISCY-LES-MOULINEAUX CEDEX I Comments should be sent within six months after the date of publication to I Edition approved for publicat
7、ion 1995-1 1-30 AECMA Gulledelle 94 B-1200 BRUXELLES AIB/TFG Chairman Mr K. Schneider aecma 1995 AECMA PRENxb041 95 1012311 0010025 5T3 = Page 2 prEN 6041 : 1995 Contents list 1 Scope 2 Normative references 3 Definitions 4 Principle of the method 5 Designation of the method 6 Apparatus 7 Test specim
8、ens 8 Procedure 9 Presentation of the results 10 Test report Annex A Equipment AECIA PREN*bOYL 95 m l10123LL 00L002b 43T m Page 3 prEN 6041 : 1995 1 Scope This test method defines the procedure for the determination of the curing-characteristic and glass transition temperature of non-metallic materi
9、als (e.g. preimpregnated and neat resin systems, adhesives) for aerospace use by Differential Scanning Calorimetry (DSC). The results obtained by this method may be useful for: - derivation of the optimum cure cycle (only together with other test methods e.g. Tg determination) - assessment of the co
10、ndition of the resin - assessment of the ageing behavior of the resin 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 references This
11、 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 of these publica
12、tions 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 and fibre content
13、 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 ) 3 Definitions The determination of these parameters shall be agreed upon betwe
14、en manufacturer and purchaser in case of non-ideal curves or different instrument types. 3.1 Curing reaction (see figure 3) e To, T, AH AHloo is the reaction enthalpy corrected to 100% resin content, in J / g is the heating rate, in OC / min or OK / min is the onset temperature, in OC or OK is the p
15、eak maximum temperature, in OC or OK is the reaction enthalpy, in J / g 3.2 Calibration (see 6.5) T, AHm is the melting temperature, in OC or OK is the enthalpy of fusion, in J / g ) Published as AECMA Prestandard at the date of publication of this standard AECMA PRENrb041 95 = 1012311 0010027 376 A
16、nalysis of non-metallic materiais (uncured) Page 4 prEN 6041 : 1995 EN 6041 3.3 Glass transition (see figure 2) Tg, Tg, Tg is the onset temperature of transition, in OC or OK is the end temperature of transition, in degrees OC or OK is the glass transition temperature, in degrees OC or OK 4 Principl
17、e of the method Differential Scanning Calorimetry (DSC) measures the temperatures and the heat flow associated with transitions in materials as a function of time and temperature. 5 Designation of the method The designation of the method used shall be drawn up according to the following example : Nu
18、mber of this standard 3 6 Apparatus 6.1 The test shall be performed in a Differential Scanning galorimeter (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 purchaser a
19、re 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 Calibration The equipment shall be controlled using a pure indium sample to mai
20、ntain a temperature accuracy to & 0,5OC and a calorimetric precision within 1% during test. Periodically the temperature and cell constant shall be calibrated using pure samples of the materials specified in table 1 (type and values according to DSC manufacturer recommendations). Temperature calibra
21、tion shall be performed using two or preferably three materials over the temperature range of interest. Sub-ambient temperature operation shall be achieved by the application of sub-ambient accessories specifically designed for use with the particular instrument being used (see 8). For sub-ambient o
22、perations ice (H,O or cyclohexane) shall also be used for calibration (the starting temperature shall be below -4OOC). The heating rate for calibration shall be the same as used in the subsequent experiments .e. 10 OC/min for standard operation (see 8). The instrument calibration shall be performed
23、using the same sample pan type, purge/purge rate and equivalent thermal mass samples as will be used in subsequent experiments. AECMA PRENrb041 95 1012311 0010028 202 Page 5 prEN 6041 : 1995 The base line and the cell shall be checked periodically (interval to be agreed between the parties). The bas
24、e 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 Test specimens shall be selected in accordance with the sampling Specification. Each sample shall comprise approximately the equivalen
25、t of 7 to 10 mg prepreg). In case of extreme enthalpy of reaction the sample size of the acceptable curves in the diagram. procedure defined in the Material of neat resin (for example 20 mg of material may be adjusted to achieve The sample mass shall be determined to 0,Ol mg (see 6.2). For quantitat
26、ive measurements it is necessary to correct the AH to 100% resin content (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.g. release testing). For determination of standard deviations a m
27、inimum of six specimens are necessary (.e. qualification programs). 7.1.1 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 Si02)is p
28、resent, it shall be determined separately (after the removal of the fibre) by centrifuging and its mass added to the reinforcement content. 7.1.2 Determination of actual carrier / resin content for adhesives Usual extraction technique : use ultrasonic bath and appropriate solvent such as DMF, DMSO,
29、NMP Determine the carrier weight after twice flushing with solvents 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 conten
30、t : mresin - madhecive - mcarrier 7.2 Conditioning 7.2.1 Conditioning of material stored at ambient temperature For material stored at ambient temperature, the amount of material (together with the release film on it) required for testing shall be sampled and conditioned in the standard atmosphere (
31、defined in EN 2743) for a minimum of 2 h, unless otherwise specified. AECMA PRENth04L 95 = LOL23LL OOLOO29 149 Page 6 prEN 6041 : 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
32、an airtight bag (containing a suitable desiccant) to prevent moisture pick-up, shall be allowed to reach 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 (tog
33、ether with the release film on it) 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. 7.2.3 Standard atmosphere for testing The test equipment shall be at (23 f 2)OC and (50 f 51% relative humidity (
34、EN 2743 B conditions). The actual test environment is controlled inside the equipment. 7.2.4 Time interval 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 c
35、arried out. 8 Procedure The sample shall be placed in a sample pan ensuring that it is in 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.
36、11, close the system and purge with pure, dry nitrogen (preferred flow 20 to 30 ml/minl. Where the Tg of the resin is required, cool the cell rapidly to below the starting temperature (see below). The following test conditions shall apply: - reference sample empty sample pan and lid (if necessary co
37、ntaining inert material for example alumina. - atmosphere Nitrogen (see 6.4) - test start temperature 40 C below start of expected Tg, unless otherwise specified - test end temperature After the end of the region of interest - heating rate 1 OC/min standard, unless otherwise specified For qualificat
38、ion program additional 5 OC/min and 20C/min may be used. - a record of heat flow (dq/dt) versus temperature shall be obtained between test start and test end. 9 Presentation of the results The glass transition temperature (Tg) shall be determined as shown in figure 2. In a non-ideal situation an agr
39、eement between the parties (see 3) shall be obtained. AECMA PRENxb041 95 m 1012311 0010030 960 m Page 7 prEN 6041 : 1995 The following features from the reaction exotherm curve shall be determined as shown in figure 3. In a non-ideal situation an agreement between the parties (see 3) shall be obtain
40、ed. where : To, is the onset temperature(s1, in OC is the temperature (s) of peak maximum (maxima), in OC AH is the reaction enthalpy, in J / g AH , is the reaction enthalpy corrected to 100% resin content, in J / g TP 9.1 Quantitative check Peaks should be within k 2 OC, reaction enthalpies AH with
41、in 2 5 % of their means. If greater, the results should be scrutinized to see if they are acceptable. 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
42、etc. 10.2 All details about the preparation of the specimens including 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 E
43、quipment and test parameters used including temperature range and heating rate. 10.6 individual test results of Tg, Tos, T, AH, AH, 10.7 Any incident which may have affected the results and any deviation from this standard. AECMA PREN+b04L 95 = LOL23LL OOLOO3L 8T7 Page 8 prEN 6041 : 1995 I T see fig
44、. 2 Figure 1 : Reference curve (idealized) line TSe, + Tg, Tg = CI = maximum peak of the derivative curve 2 Figure 2 : Measurement of glass transition temperature (idealized) AECMA PRENUhOLiL 95 10L23LL OOL0032 733 Page 9 prEN 6041 : 1995 Determine the temperature at onset of the cure reaction (f,)
45、by extrapolating the base line and the tangent drawn at the point of greastest slope on the leading edge of the exotherm peak. The use of alternative baselines are acceptable if agreed between the parties. Points A and B together with the tangent at the turning point (Tos) may be determined from a d
46、erivative 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 3 : Evaluation of the reaction exotherm curve (idealized) - AECMA PRENxb041 95 1012311 0010033
47、bT Material Page 10 prEN 6041 : 1995 T, (Cl AH, J/gl Table 1 : Melting temperatures and enthalpies of fusion of calibration materials Pb 327,5 I I I I I 1 56,6 28,59 231,9 6038 Cyclohexane I 419,5 I I 63 _ AECMA PRENxb04L 95 LOL23LL OOL0034 506 = Page 11 prEN 6041 : 1995 Annex A : Equipment The foll
48、owing equipment may be used : A.l Mettler TA 3000 / TA 2100 - 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.
