1、June 2007DEUTSCHE NORM English price group 11No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 25.220.20!,x|*“9858907www
2、.din.deDDIN EN 15340Thermal spraying Determination of shear load resistance of thermally sprayed coatingsEnglish version of DIN EN 15340:2007-06Thermisches Spritzen Bestimmung des Scherbeanspruchungswiderstandes bei thermisch gespritzten SchichtenEnglische Fassung DIN EN 15340:2007-06www.beuth.deDoc
3、ument comprises 17 pages 09.07DIN EN 15340:2007-06 2 National foreword This standard has been prepared by CEN/TC 240 “Thermal spraying and thermally sprayed coatings” (Secretariat: DIN, Germany). The responsible German body involved in its preparation was the Normenausschuss Schweitechnik (Welding S
4、tandards Committee), Joint Committee NA 092-00-14 AA Thermisches Spritzen und thermisch gespritzte Schichten (DVS AG V 7). The European and International Standards referred to in clause 2 and in the bibliography have been published as the corresponding DIN EN, DIN EN ISO or DIN ISO Standards. EUROPE
5、AN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 15340March 2007ICS 25.220.20English VersionThermal spraying - Determination of shear load resistance ofthermally sprayed coatingsProjection thermique - Dtermination de la rsistance aucisaillement des revtements obtenus par projectionthermiqueThermisches Sp
6、ritzen - Bestimmung desScherbeanspruchungswiderstandes bei thermischgespritzten SchichtenThis European Standard was approved by CEN on 3 February 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status
7、of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A vers
8、ion in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denma
9、rk, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONE
10、UROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 15340:2007: EEN 15340:2007 (E) 2 Contents Page Foreword3 Introduction .4 1 Scope 5 2 Normative r
11、eferences 5 3 Terms and definitions .5 4 Equipment 6 5 Specimens 7 5.1 Shape 7 5.2 Preparation .8 5.3 Number of specimens to be tested9 6 Procedure .9 7 Results 9 8 Test report 9 Annex A (informative) Evaluation11 Annex B (informative) Coating systems and sources of error .14 B.1 Coating systems (bo
12、nd/top coat).14 B.2 Faults in testing .14 Bibliography 15 EN 15340:2007 (E) 3 Foreword This document (EN 15340:2007) has been prepared by Technical Committee CEN/TC 240 “Thermal spraying and thermally sprayed coatings”, the secretariat of which is held by DIN. This European Standard shall be given t
13、he status of a national standard, either by publication of an identical text or by endorsement, at the latest by September 2007, and conflicting national standards shall be withdrawn at the latest by September 2007. According to the CEN/CENELEC Internal Regulations, the national standards organizati
14、ons of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania
15、, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 15340:2007 (E) 4 Introduction The test is conducted to determine the shear load resistance of the bond between the spray deposit and the parent material (adhesive strength) and/or the strength of the coating itself (cohesive str
16、ength). If adhesive strength of the sprayed coating to the base material supersedes the cohesive strength, primarily the cohesive strength of the deposit is determined. During the test the coating is loaded parallel to the interface of coating/substrate. The test is used to evaluate the effects of p
17、arent material and spray material, surface preparation of the work piece before spraying, and the spraying conditions on the adhesive and/or cohesive strength of thermally sprayed coatings, or for quality control and routine supervision of the spray works. EN 15340:2007 (E) 5 1 Scope This European S
18、tandard specifies the procedure for determination of the shear load resistance of thermally sprayed coatings, provided that a minimum thickness is given. Additionally this European Standard defines the shear load resistance and the designation of the fractures structure on the test specimen, which o
19、ccurs when the shear adhesive or adhesive/ cohesive or cohesive strength of the coating or the coating system will be exceeded. The test report is the basis for comparative statements regarding shear load resistance and structure of fracture. NOTE The test for the determination of the shear load res
20、istance is not recommended for sprayed coatings thinner than approximately 150 m because the adjustment of shear distance becomes critical. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited a
21、pplies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 657:2005, Thermal spraying Terminology, classification EN ISO 7500-1, Metallic materials Verification of static uniaxial testing machines Part 1: Tension/compression testing machines
22、Verification and calibration of the force-measuring system (ISO 7500-1:2004) ISO 1832, Indexable inserts for cutting tools Designation 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 657:2005 and the following apply. 3.1 shear strength FSa maximum for
23、ce that causes fracture of the specimen in the interface coating/substrate NOTE This fracture mode is called “Mode 1”. 3.2 shear adhesive/cohesive strength FSa/c maximum force that causes mixed fracture partially within coating material and partially in the interface coating/substrate NOTE This frac
24、ture mode is called “Mode 2”. 3.3 shear cohesive strength FSc maximum force that causes fracture of the specimen within the coating material NOTE This fracture mode is called: EN 15340:2007 (E) 6 “Mode 3a” - if in case of hard coatings continuous blistering of small or larger pieces of the coating o
25、ccurs; - if soft and/or porous coatings will be compressed and continuously scraped off; “Mode 3b” - if the fracture path runs within the coating especially parallel to the interface coating/substrate and the coating part under the shear plate detaches in one piece 3.4 shear energy ES area below the
26、 force displacement curve provided by the shear test NOTE The energy ES up to the first shear force maximum can be calculated using the force-displacement curve provided by the shear test. The energy ES relates to the energy absorption of the coating-substrate system until failure. 3.5 shear distanc
27、e d distance between interface coating/substrate and the edge of the shear plate 3.6 shear load resistance value of the first maximum of the load during the shear test process 4 Equipment The shear test may be performed using a universal testing machine in accordance with EN ISO 7500-1 class 2.5 or
28、using stand alone desk top machine which fulfils the corresponding requirements for accuracy and reproducibility. The construction of the testing machine shall be able to apply a force required for the operation. The principle of the testing set up is demonstrated in Figure 1. EN 15340:2007 (E) 7 Ke
29、y 1 load cell 6 specimen holder 2 guided punch 7 displacement gauge 3 shear plate (cutting tool) 8 data processing 4 coating 9 test load 5 specimen Figure 1 Principle of shear test An exact fixation and alignment of the specimen in the specimen holder is necessary and any movement of the specimen du
30、ring the shear test shall be avoided. The shear plate is preferentially made of hard metal. A suitable cutting plate without “swarf crusher” (ISO 1832 standardized e.g. SP EW 120408 (turning, 110clearance angle) or LC EW 1904PPF (milling, 70clearance angle) ensures proper test conditions. The shear
31、plate is fixed in a suitable manner to a punch or cantilever that allows a movement during loading in the guide ways without deviations or friction that affects the measured shear force. The edge of the shear plate shall be parallel to the interface coating/substrate and parallel to the upper face o
32、f the specimen. Thus a uniform loading of the coating is ensured. 5 Specimens 5.1 Shape The dimensions of the specimen for the determination of the shear load resistance of sprayed coatings are shown in Figure 2. EN 15340:2007 (E) 8 Dimensions in millimetres Key 1 area to be coated Figure 2 Dimensio
33、ns of the specimen The mentioned tolerances shall be complied with for measuring/adjusting the shear distance even from the back side of the specimens. For tolerances not specified 0,1 mm shall apply. After surface preparation the coating is sprayed to the front area of 5 mm 10 mm. When the specimen
34、s are coated in a rotating specimen holder safe fastening against centrifugal forces shall be ensured e.g. form-locking by pin and hole or notch, as shown in Figure 3. Dimensions in millimetres Figure 3 Examples of specimen layout for form-locking safety of specimens during rotational coating 5.2 Pr
35、eparation The specimen is made of the specified material and shall be pre-treated in the same way as the work piece in practice. After surface preparation and before spraying, the length of the specimen has to be measured as a reference. The coating or the coating system is applied to the front face
36、 5 mm 10 mm. No spray material shall be deposited on the other sides. The coating thickness shall be constant. Spray conditions shall be equal to those of practical work. For spraying a set of specimens they may be inserted as a batch in an adequate specimen holder. In that case it has to be guarant
37、eed that each specimen is mechanically separated, for example by thin copper foils. The separating elements shall not reach the coating area. Unavoidable overspray on the sides of the specimen shall be removed by abrasive paper (120 grit recommended) moving carefully from the coating to the substrat
38、e. Care shall be taken to ensure the perpendicular position of specimen faces after cleaning. Other post treatments should be done only if it belongs to the treatment of the work piece in practice. Before carrying out the test, the coating thickness should be measured non-destructively or by metallo
39、graphic examination on an accompanying specimen. Care shall be taken when measuring the coating thickness by slide gauge in order to avoid that measured values are not overestimated due to coating roughness and/or loosely bonded particles on the surface. EN 15340:2007 (E) 9 5.3 Number of specimens t
40、o be tested For statistical reasons, at least five specimens, spray deposited in one cycle, should be tested. 6 Procedure Before performing the tests, the edge of the shear plate shall be inspected to prove that no damage has occurred during the preceding loading. The coated specimen is inserted int
41、o the specimen holder of the test device. Concerning shear distance the roughness of the specimen shall be taken into account. Thus, the shear distance d shall be 50 m 20 m (see Figure 4). Within this range the distance does not have a significant influence on the result. Then the specimen is secure
42、ly clamped. Any movement of the specimen during loading, lateral, back, or tilting shall be avoided. The coating is loaded according to Figures 1 and 4 by thrust of the shear plate at a constant rate and without jerks until fracture occurs and the recorded load decreases. A suitable speed of the she
43、ar plate is about 50 m/s. Key 1 specimen 3 shear plate 2 shear force d shear distance Figure 4 Shear distance d 7 Results The shear load resistance is taken from the first maximum of the force displacement curve. Typical force displacement curves are schematically shown in Annex A, Figures A.1 to A.
44、5. After completing the tests, the arithmetic mean value in N and standard deviation of the determined shear forces (FSa, FSc, or FSa/c) for all evaluated specimens shall be calculated. The standard deviation of the test shall be less than 10 %. Otherwise the test shall be repeated. The fractures st
45、ructure is important for the evaluation of the shear load resistance. Therefore the fracture mode shall be indicated in the test report. 8 Test report The test report shall contain the following information for every specimen tested in accordance with this European Standard: a) inspection body, insp
46、ector, date; EN 15340:2007 (E) 10 b) specimen material; c) coating thickness; d) coating material; e) shear distance d; f) shear plate geometry according to ISO 1832; g) speed of shear plate; h) list of all single measurement results of the shear load resistances N including type of fracture: “Mode
47、1”: FSa (failure at interface between coating and substrate); “Mode 2”: FSa/c (mixed fracture, portion of the coating peeled off in area-%); “Mode 3a” / “Mode 3b”: FSc (failure within the spray deposit); i) arithmetic mean value and standard deviation of results; j) any particularities. EN 15340:200
48、7 (E) 11 Annex A (informative) Evaluation Depending upon the coating material and its adhesion to the substrate and cohesion between the splats, different modes of fracture can be distinguished. This can be seen from the load-displacement curves. Typical curves and sketches of crack configuration ar
49、e shown schematically in Figures A.1 to A.5. Mode 1 coating adhesion coating cohesion Mode 3a coating disintegrates (crumbles) into small particles Key Y shear load N X displacement Figure A.3 Typical schematic load displacement curve and crack configuration during shear testing for Mode 3a failure of hard coatings EN 15340:2007 (E) 13 During shear testing of hard coatings continuous blistering of small or larger pieces of the coating may happen. Key Y shear load N X displacement 1 ductile behaviour (no
