Standard test method for Determination of Tensile Strength of Coatings by Portable Adhesion Tester

The publication classification number of this standard is D 4541; The numbers following the classification numbers represent the time of initial use and, in the case of revisions, the last revision year. The numbers in parentheses represent the year of the last permit. The superscript (ε) represents a version change since the last revision or sublicense.

1. Scope of application *
1.1 This test method describes the test method for evaluating the tensile strength (often referred to as adhesion) of metal substrate coating systems. Test method D7234 describes the tensile strength of the concrete coating. This test is used to determine the maximum vertical force (tensile force) that the surface can withstand before the material is separated, or whether the surface can remain intact under a given force (passed/failed). The weakest plane in a planar system of test fixtures, adhesives, coating systems, and substrates will break along this plane, resulting in fracture surfaces. This test method maximizes tensile stress compared to shear stress used by other methods, such as scraper or cutting adhesion, and their results are not comparable.

ASTM D 4541-2009 Determination of Tensile Strength of Coatings by Portable Adhesion Tester

Note 1 – The procedures of this standard are used for metal substrates, but can also be used for other hard substrates such as plastic and wood. The user/special person needs to indicate the load speed and elasticity of the substrate.

1.2 The tensile strength depends on the material and equipment parameters. Different test methods can give different results, so the results presented should indicate the test method used and should not be compared with the results of other equipment. There are five equipment models, numbered B-F. The test method should be indicated when reporting the results.

Note 2 — Method A, which appeared in a previous version of this standard, is now used mainly for testing concrete substrates (see Test Method D 7234) and is therefore no longer used in this standard. .

1.3 This test method uses a series of portable tensile and detachment adhesion tester. 2 They are able to apply concentric and reaction loads to a single surface, so that even one coating can be tested. The adhesion strength of the loading fixture and the surface of the sample or the cohesion of the adhesive, coating and substrate determines the magnitude of the test results.

1.4 This test is destructive and requires on-site maintenance.

ASTM D 4541-2009 Determination of Tensile Strength of Coatings by Portable Adhesion Tester

1.5 MPa (inch-pound) was used as the standard unit for the test. The values in parentheses are for reference only.

1.6 This standard is not intended to address all safety issues related to use, so there may be safety issues. It is the responsibility of users of standards to establish appropriate safety and sound procedures; And before use, users need to determine the rules and regulations of use.

2. Normative reference documents
2.1 ASTM Standard: 3

D 2651 Standard treatment method for metal surfaces for adhesive bonding

D 3933 Methods of treatment of aluminum surfaces for bonding with structural adhesives (phosphoric acid anodization)

D 3980 Inter-laboratory test method for paints and related materials 4

D 7234 Standard Test Method for Determination of Tensile Bond Strength of concrete Coatings by Portable Bond Tester

E 691 Method for conducting interlaboratory precision tests

2.2 ANSI Standards:

N 512 Nuclear industry protective coating (paint) 5

ASTM D 4541-2009 Determination of Tensile Strength of Coatings by Portable Adhesion Tester

2.3 ISO Standards:

ISO 4624 Paints and varnishes — Tensile test 5

This test method is under the jurisdiction of ASTM Paints and Related Coatings, Materials, and Applications Committee D01 and is directly under the responsibility of Industrial Protective Coatings Subcommittee D01.46.

The current version was licensed on February 1, 2009 and published in April 2009. This standard was originally licensed in 1935, and the previous version was licensed in 2002 under classification number D4541-02.

The TERM ADHESION TESTER may not be APPROPRIATE, BUT IT IS USED BY two MANUFACTURERS AND AT LEAST two PATENTS.

3 Refer to ASTM standards, visit the ASTM website at www.astm.org, or contact ASTM Customer service at [email protected]. For annual volume information on ASTM standards, see the standard Document summary page on the ASTM Web site.

4 Repeal.

5 Available from the American National Standards Institute (ANSI), 4th Floor, 25 W. 43rd Street, New York, NY 10036, at http://www.ansi.org

* A summary of the changes is given at the end of this standard

Copyright ASTM International, 100 Bar Harbor Road, West Conshoherken, PA 19428, USA.

3. Summary of test methods
3.1 The general method used in the pull test is to fix a load fixture in the normal (vertical) direction of the coating with adhesive. After the adhesive is cured, a tester is connected to the load fixture to jointly apply normal tension to the test surface. Gradually increase the force applied to the load fixture and observe whether the filler of the material is separated or whether the applied force reaches the specified value. When the material filler is separated, the exposed surface represents the finite strength surface in the system. The nature of the separation is related to the percentage of adhesion and adhesive separation, as well as the actual interface and associated layers. The maximum load displayed, the equipment calibration data, and the original surface zone stress were used to calculate the tensile strength. The tensile strength obtained by different instruments differs because the results are affected by the equipment parameters (see Appendix X1).

ASTM D 4541-2009 Determination of Tensile Strength of Coatings by Portable Adhesion Tester

4. Significance and usefulness of the test
4.1 In the specification, the tensile strength of the coating is an important property. This test method is a unified method for coating surface preparation and testing, evaluation and reporting of results. This test method is applicable to all portable instruments that meet the basic requirements of coating tensile strength test.

4.2 Testing the same coating using different instruments or substrates may produce different results (see Section 10). Therefore, it is recommended that both parties of the test reach a consensus on the instrument model and substrate to be used.

4.3 When using this standard, the Buyer or person shall specify a special test method, i.e. B, C, D, E or F.

ASTM D 4541-2009 Determination of Tensile Strength of Coatings by Portable Adhesion Tester

Step 5: Instrument
5.1 Adhesion test instruments are available, and specific examples of similar instruments are listed in Appendix A1-Appendix A-5.

5.1.1 One end of the load fixture is flat and can be bonded to the coating, and the other end is connected to the tester.

5.1.2 The separation device (adhesion force tester) has a central clamp for controlling the fixture.

5.1.3 The separation device shall have a base or annular support ring or intermediate support ring directly and uniformly pressed on the coated surface around the fixture. The base needs to be aligned so that the applied force is in the normal direction of the surface.

5.1.4 When removing the plier from the base, it should be as smooth and continuous as possible, so that the force between them is not torsional and is co-axial (the pull force of the plier and the thrust force of the base cannot be in the same axial direction).

5.1.5 Use a timer or other method to limit the load speed to 1 MPa/s (150 psi/s) or the load fixture to less than 20mm to ensure that the test is completed in 100s or less time. A timer and 5.1.6 force display are the minimum equipment required by the operator.

5.1.6 Force display and calibration information to determine the actual force applied to the load fixture.

5.2 Use solvents or other methods to clean the surface of the load fixture. Fingerprints, moisture and oxides are the main pollutants.

5.3 Clean the coating with fine sandpaper or other methods, taking care that the integrity of the coating cannot be changed by using compounds or solvents. If light grinding is used, choose a very fine (400 mesh or finer) abrasive that does not cause scratches or residue.

5.4 Adhesive 6, which is used to secure the fixture to the coating without affecting the properties of the coating, epoxy and acrylate are desirable choices.

5.5 If necessary, use magnetic or mechanical clamps to secure the test fixture while the adhesive is curing.

5.6 Use cotton swabs or other methods to remove excess adhesive and mark the adhesion area. When CLEANING THE excess adhesive, it is important to avoid damage to the surface, such as scratching (see 6.7), as the resulting inductive surface scratching can cause the coating to break early.

5.7 Round hole cutter (optional) for cutting the substrate around the load fixture.

ASTM D 4541-2009 Determination of Tensile Strength of Coatings by Portable Adhesion Tester

6. Test preparation
6.1 The method of selecting the coating location for the preparation of the test shall be determined according to the purpose of the test and the agreement between the parties hereto. However, general test methods and instruments have some physical limitations on the choice of location. All locations should meet the following requirements:

6.1.1 The selected test area should be flat and large enough to carry out the specified number of repeated tests. The surface may have any reference gravitational direction. The distance of each experimental location should be sufficient to install the separation instrument. The size of the test position is the size of the fixed load fixture. At least three replicates of the experiment were performed before the characteristics of the experimental area could be counted.

6.1.2 There should be enough space to install the instrument in the vertical and radial direction of the selected area. It should be flat enough to draw straight lines and hard enough to withstand reaction forces. It is important to note that the test near the edge is not representative of the entire coating.

6.2 The hardness of the substrate will affect the tensile strength results and is an uncontrollable variable measured in the field, so the thickness and composition of the substrate should be reported to facilitate analysis or laboratory comparison. For example, a substrate thickness of 3.2 mm (1⁄8 in.) tends to have less tensile strength than a substrate thickness of 6.4 mm (1⁄4 in.).

6.3 Referring to the requirements of 6.1, select representative test areas and clean their surfaces, taking care that the method used does not affect the integrity of the coating or produce residual substances. To prevent the adhesive from breaking, the surface of the coating can be gently scraped to improve the adhesion of the adhesive. If the surface has been scraped, be careful not to damage the coating or severely reduce the thickness of the coating. Use solvent to clean the scraped material. The selected solvent should not remain on the coating.

6 6Scotch weld 420, available from the Adhesives, Coatings and Sealants Division, 3M, used in the joint declaration is 3M Center, Sao Paulo, MN 55144.

6.4 Clean the load fixture according to the requirements of the load fixture manufacturer. Fracture of the jig – adhesive interface can often be avoided by treating the jig surface in accordance with ASTM standard method for metal surfaces for adhesive bonding.

Note 3 — Methods D 2651 and D 3933 are typical examples that have been shown to increase the bonding force between adhesives and metal surfaces.

6.5 Handle the adhesive as recommended by the adhesive manufacturer. Apply the adhesive to the fixture or surface to be tested using the method recommended by the adhesive manufacturer. Make sure the adhesive is applied to the entire surface. The fixture is facing the surface to be tested. Carefully remove the excess adhesive from the fixture. (Warning-motion, especially twisting, can cause small bubbles to condense into large bubbles, causing stress discontinuity during the test.)

Note 4 — Add 1%#5 glass beads to the adhesive to facilitate test fixture and surface alignment.

6.6 Give the adhesive sufficient time to cure and reach the recommended degree of hardening according to the adhesive manufacturer’s recommendations and test environment conditions. A fixed contact force is applied to the fixture during the adhesive curing and early hardening stages. Magnetic or mechanical clamps perform well, but when using a viscous system such as tape, care is taken to ensure that it does not loosen over time and allow air to enter the clamps and test area.

6.7 The test standard tests unaltered coatings, and this rationale is violated if there is a scratch around the fixture. If there are scratches around the test surface, special care should be taken to prevent the development of small cracks on the coating surface, as cracks will decrease the adhesion value. Samples with scratches are different tests and the results need to be specifically reported for this process. Only thick film coatings with a thickness greater than 500 µm (20 mils), reinforced coatings and elastic coatings are acceptable for scratching. If there is a scratch, make sure that the cut is in the normal direction of the coating surface and does not distort and torque the test area, generate minimum heat and damage to the edge, and create minimum cracks in the coating and substrate. Thick coatings recommend the use of water lubricant to cool the coating and substrate during the cutting process.

Note 5 — Having holes of the same size glued to the die is an effective way to prevent the bit from moving sideways.

6.8 Indicate the exact temperature and relative humidity during the test.

ASTM D 4541-2009 Determination of Tensile Strength of Coatings by Portable Adhesion Tester

7. Test process
7.1 Test method:

7.1.1 Test method A (Discontinued).

7.1.2 Test Method B — Fixed Pair Adhesion Tester, Model II:

7.1.2.1 Operate the instrument in accordance with Appendix AnnexA1.

7.1.3 Test Method C — Self-Aligned Adhesion Tester, Model III:

7.1.3.1 Operate the instrument in accordance with Appendix AnnexA2.

7.1.4 Test Method D — Self-aligned Adhesion Tester, Model IV:

7.1.4.1 Operate the instrument in accordance with Appendix AnnexA3.

7.1.5 Test Method E — Self-aligned Adhesion Tester, Model V:

7.1.5.1 Operate the instrument in accordance with Appendix AnnexA4.

7.1.6 Test Method F — Self-aligned adhesion Tester, Model VI:

7.1.6.1 Operate the instrument in accordance with Appendix AnnexA5.

7.2 Use a separation device and its compatible load fixture that can generate the desired calibration force range. It is fine to use mid-range values, but refer to the manufacturer’s operating instructions before doing so.

7.3 If a support ring or similar device (5.1.3) is applicable, place it in the center of the load fixture on the coated surface. If a gasket is required, place it between the tester base and the support ring, not on the coated surface.

7.4 Carefully place the center clamp of the separation device on the load fixture, so as not to rebound, bend or prestress the sample; If necessary, connect the separation device according to the control mechanism of the separation device. If the surface of the separation device is not level, use a support to level it so that its weight does not affect the force applied during the test.

7.5 Align the instrument according to the manufacturer’s instructions and set the force display to zero.

Note 6 — Accurate alignment is important, see Appendix X1. If alignment is required, use the manufacturer’s recommended alignment of the bonding tester and report the process used.

7.6 Uniformly and continuously increase the load on the fixture at a speed of 1 MPa/s (150 psi/s) or the load fixture less than 20 mm to ensure that the test is completed in 100s or less time.

7.7 Record the applied force or maximum force applied at the time of fracture.

7.8 If the filler of the material is separated, mark and store the fixture in accordance with the requirements of 8.3 for inspection of the fracture surface.

7.9 Report errors during the experiment, such as possible deviations, delays in applying force, etc.

ASTM D 4541-2009 Determination of Tensile Strength of Coatings by Portable Adhesion Tester

8. Calculation and result discussion
8.1 Use the instrument calibration factor to convert the forces shown in each test to the forces actually applied, if specified by the manufacturer.

8.2 The calibration chart given by the manufacturer can be used, or the relative stress applied to each coating can be calculated as follows:

X=4F/πd2 (1)

Among them:

9.1.4 If necessary, introduce the test system using the chart indicators listed in 8.3, including: product density, general type of coating and other information given,

X = In pass/fail tests is the maximum average tensile stress, or the maximum tensile strength at break. The unit is MPa (psi),

The actual force applied to the test surface determined in F = 8.1,

d = equivalent diameter in inches (or millimeters) of the original surface area under stress. This value is often equal to the diameter of the load fixture.

8.3 Estimate the percentage of adhesion and adhesive fracture for all fracture tests according to their respective area and location in the coating and adhesive layer test system. 8.3.1 to 8.3.3. An easy-to-use master test system is given (see ISO 4624.)

Note 7 — ISO 4624 uses a laboratory tensile tester.

8.3.1 The sample is defined as substrate A, which is coated with B, C, D, etc., including adhesive Y, which fixes fixture Z to the top coating.

8.3.2 Cohesion breaks are numbered A, B, C, etc., and their percentages are recorded.

8.3.3 The interfacial attachment rupture is numbered A/B, B/C, /DC, etc., and its percentage is recorded.

8.4 Recording or calculation errors can produce a value that is different from most results. If not for these two reasons, check the environment of the trial. If the reason for the experiment produces an irregular value, this value is not used in the analysis. However, there is no valid non-statistical reason or the statistics do not indicate that the result is an outlier and no value can be removed. The effective non-statistical reasons are the instrument is not aligned to the normal direction of the surface, the stressed interface is blurred due to the improper use of adhesives, the glue line and boundary are not well defined, the large bubbles caused by cavities or inclusions, the improper surface treatment, and the slipping or distortion of the jig during the initial curing stage. Scraping or scratching will concentrate the stress and the sample will break prematurely. The Dixon test for D 3980 can be used to detect outliers.

8.5 Tests with less than 50% glue zone will not be considered. If the pass/fail standard is used and the glue pull strength is greater than the standard value, report the result: “Pass, pull strength is: {value obtained}…”

8.6 See Appendix X1 for more relevant information on the interpretation of the test results.

ASTM D 4541-2009 Determination of Tensile Strength of Coatings by Portable Adhesion Tester

9. Test report
9.1 Report the information:

9.1.1 Briefly describe the nature of the test, such as field or laboratory tests, general type of coating, etc.

9.1.2 Temperature, relative humidity and other relevant environmental conditions during the test.

9.1.3 Describe the instrument used, including: manufacturer and model, load fixture model and size, and support ring model and size.

Substrate density (thickness, type, orientation, etc.), and adhesive used.

9.1.5 Test results

9.1.5.1 Date, test site and test institution.

9.1.5.2 For pass/fail experiments, the stress applied should be recorded along with the results, such as the plane that passed or failed and broke (see 8.3 and ANSI N512).

9.1.5.3 For failed tests, report the values calculated in accordance with 8.2, and the nature and location of the fracture as specified in 8.3; If only the average intensity is required, only the average intensity of the statistics is reported.

9.1.5.4 If the results have been modified or the minimum, maximum or other values have been removed, the criteria used to report the reasons for the adjustment.

9.1.5.5 For tests with scratchings, use a footnote next to the affected data point and a footnote at the bottom of the data page to describe the effect. Note all other deviations from the process.

ASTM D 4541-2009 Determination of Tensile Strength of Coatings by Portable Adhesion Tester

10. Precision and deviation
10.1 The precision of this test method is based on the interlaboratory Standard Test Method Study D 4541 conducted in 2006. It analyzes the results of six different coatings on 1⁄4 inch thick hot rolled carbon steel from seven laboratories using five different adhesion testers. Each “trial outcome” represents an independent decision. In order to standardize and balance the data, the statistical analysis dropped all pulls that exceeded the tester’s reserve limit, as well as pulls that broke 50% or more of the glue. If one OPERATOR obtains four reasonable data, delete the fourth, and the first three reasonable data are the test results (from one operator) of the material used for statistical analysis. Data were designed and analyzed using Method E 691, as detailed in report D01-1147.

Note 8 — The tensile strength of the two coatings, referred to in the joint statement as coating A and coating F, exceeded the upper limit of the tester’s alternative measurement at the time of the test and were not analyzed in the statistical analysis.

10.1.1 Repeatability — If the difference between two test results of the same material in the same laboratory is greater than the “r” value, the test results of the material are different; “r” is the maximum difference allowed to be produced by the same operator, in the same laboratory, using the same instrument for the same material.

10.1.1.1 Repeatability limits are listed in Tables 1-5.

10.1.2 Reproducibility — If the difference between two test results is greater than the “R” value, the test results of the material are not the same. “R” is the maximum allowable difference of the same material measured by the same operator in the same laboratory using the same instrument.

10.1.2.1 Reproducibility limits are shown in Tables 1-5.

7 Support data are available from ASTM International headquarters. Required RR: D01-1094.

8 Support data are stored at ASTM International headquarters and are available upon request in research report RR: D0 1-1147.

TABLE 1 Adhesion test method B, Tensile strength (psi)

TABLE 4 Adhesion test method E, Tensile strength (psi)

ASTM D 4541-2009 Determination of Tensile Strength of Coatings by Portable Adhesion Tester

TABLE 2 Adhesion test method C, Tensile strength (psi)

TABLE 5 Adhesion test method F, Tensile strength (psi)

TABLE 3 Adhesion test method D, Tensile strength (psi)

ASTM D 4541-2009 Determination of Tensile Strength of Coatings by Portable Adhesion Tester

10.1.3 The accuracy rate of using these two judgment criteria is 95%.

10.2 Bias — There is no suitable reference material to determine the bias of the experiment, so it will not be discussed.

10.3 Precision is derived from statistical analysis of 394 experimental results obtained from four coatings tested by analysts in seven laboratories using five different instruments. Different coatings are used to obtain a range of tensile strengths that cover all instrument operation ranges.

10.3.1 If the relative percentage of the difference in results obtained by the same operator using instruments of the same method exceeds the inter-laboratory values in Table 6, it is questionable. If the relative percentage difference between the three results obtained by different operators using instruments of the same method exceeds the inter-laboratory values in Table 6, it is doubtful.

Key Words

11.1 Bonding; Coating; On site; Metal substrate; Paint; Portable; Tensile strength; Tensile test.

TABLE 6 Precision of adhesive-pull test

(Average across coating types for each instrument)

Maximum recommended difference between laboratories, % Maximum recommended difference between laboratories, %

Method B 64.7 Method B 76.0

Method C 33.8 Method C 65.9

Method D 14.8 Method D 28.4

Method E 27.8 Method E 34.1

Method F 17.5 Method F 23.0

ASTM D 4541-2009 Determination of Tensile Strength of Coatings by Portable Adhesion Tester

Accessories
(Mandatory information)

A1. Fixed Alignment Adhesion Tester, Model II (Test Method B)

A1.1 Instrument:

A1.1.1 This is a fixed alignment portable tester, as shown in Figure A1.1.9,10

Note A1.1 — Precision data for model II instruments are shown in Table 6, and the instruments used are shown in Figure A1.1. As shown.

A1.1.2 One end of the tester is a removable aluminum load fixture, and its base is a flat cone with a diameter of 20 mm (0.8 in.), which is used to fix to the coating; At the other end is an annular T-bolt head, a central clamp to hold the load fixture (deviating from the triangular base due to handwheel (or nut) interaction), coaxial bolts to connect a series of Belleville washers, or springs in the rear column that can act to relieve torsion and replace the drag indicator at a certain scale.

A1.1.3 The force is determined by measuring the maximum displacement of the spring when the force is applied. Note that the bending of the substrate does not affect its final position or the actual force applied by the spring device.

The A1.1.4 instrument has four ranges: 3.5, 7.0, 14 and 28 MPa (0-500, 0-1000, 0-2000 and 0-4000 psi).

ASTM D 4541-2009 Determination of Tensile Strength of Coatings by Portable Adhesion Tester

A1.2 Test process:

9 To the best of the Committee’s knowledge, the only supplier of a film thickness tester, Model 106, adhesion tester is Elgo Instruments UK LTD., Side Lane, Dorston, Manchester M35 6UB, England, UK.

If you know of other suppliers, please inform ASTM INTERNATIONAL HEADQUARTERS. The responsible Technical Committee will carefully consider your comments at the meeting, which you may also attend.

A1.2.1 Fix the center of the support ring to the center of the coated surface using a load fixture. Turn the hand wheel or nut of the tester counterclockwise so that the clamp drops below the load fixture head.

A1.2.2 Align or trim the rotating pad of the triangular base of the instrument so that the tension of the instrument is perpendicular to the surface of the support ring. The annular ring can be used to flex the substrate.

A1.2.3 Use idle parts between different units to set the drag (force) indicator on the tester to zero.

A1.2.4 Hold the instrument tightly with one hand. The base should not be moved or slid during the test. Turn the handwheel counterclockwise with the other hand at a uniform speed. Do not jerk, speed should not exceed 150 psi/s (1 MPa/s), allow more than 7 s/7 MPa (7 s/1000 psi) stress. If using a 14 or 28 MPa (2000 or 4000 psi) model, replace the handwheel with a nut that can be tightened with a wrench. The plane of the wrench should be parallel to the plane of the substrate to ensure that the load fixture does not move or deviate due to shear stress. Delete the result if any. Maximum stress needs to be reached in approximately 100 s.

A1.2.5 The tension applied to the load fixture increases to the maximum value or to the point where the system breaks at the weakest point. When broken, the scale will rise slightly, but the drag indicator will maintain the displayed load. The instrument will show the stress directly in pounds per square inch, but it needs to be compared with the calibration curve.

A1.2.6 Read the bottom of the drag indicator and record the highest value.

(a)

(b)

FIG. A1.1 Photo (a) and schematic (b) of Model II, fixed alignment pull tester

A2. Self-aligned Adhesion tester, Type III (Test Method C)

A2.1 Instrument:

A2.1.1 This is the self-aligned adhesion tester, as shown in Figure A2.1.11,10

As shown.

Note A2.1 — Precision data for model III instruments are shown in Table 6, and the instruments used are shown in Figure A2.1. As shown.

A2.1.2 Apply a load through a hydraulic piston and against the center of the fixture. The hole diameter of the piston shall be such that the hole area is equal to the net area of the load fixture. Therefore, the pressure generated by the load fixture is the same as the pressure of the hole and is directly transmitted to a pressure gauge.

A2.1.3 The instrument consists of a load fixture with an outer diameter of 19 mm (0.75 in.) and an inner diameter of 3 mm (0.125 in.), a hydraulic piston and needle applying force to the load fixture, a hose, a pressure gauge, a threaded plunger and a handle.

A2.1.4 The hydraulic pressure indicated by the pressure gauge is the applied force, because the piston hole and the load fixture have the same area of action.

11 To the knowledge of the Commission, the only supplier of the Heitmark VII Bond Tester is Hydraulic Bond Test Equipment Co., LTD., 629 Approach Road, North Palm Beach, Florida 33408.

A2.1.5 The three standard operating ranges of the tester are: 0-10 MPa (0-1500 psi), 0-15 MPa (0-2250 psi), 0-20 MPa (0-3000 psi). The tubular part has a special load fixture.

A2.2 Test process:

A2.2.1 Refer to the general process described in sections 6 and 7. This section describes the specialized process of this instrument.

A2.2.2 Insert the degraded PTFC-fluoro plug into the load jig until the tip protrches out of the load jig. When using adhesive on the load fixture, avoid getting adhesive on the stopper. Hold the load jig for 10s, then remove the stopper.

ASTM D 4541-2009 Determination of Tensile Strength of Coatings by Portable Adhesion Tester

A2.2.3 Ensure that the black line reading of the tester is zero. Attach the test fixture to the head and turn the handle clockwise to increase pressure until the needle protrures from the load fixture. Reduce the pressure to zero and remove the test load fixture.

A2.2.4 Pull the element ring back, push the head, release the element ring, and connect the head to the load fixture to be tested. Make sure the tester is in the normal direction of the surface to be measured and that the hose is straight.

A2.2.5 Slowly turn the handle clockwise, increasing the pressure until maximum stress is reached, or fracture occurs.

(a)

(b)

FIG. A2.1 Photo (a) and schematic (b) of Model III, self-aligned pull tester

A3. Self-aligned Adhesion Tester, Model IV (Test Method D)

A3.1 Instrument:

A3.1.1 This is a self-aligning automatic tester with a pressure source and a control module that determines the selection of a separation device or piston for different load ranges. As shown in Figure A.3.1.

Note A3.1 — Precision data for model IV instruments are shown in Table 6, and the instruments used are shown in Figure A3.1. As shown.

A3.1.2 The apparatus consists of: (1) a load fixture, (2) a separation device, or piston, (3) one of several control modules, and (4) a compressed air source.

A3.1.3 There are many different sizes of load clamps (3 to 75 mm) depending on the situation of the system under test. Standard load fixture diameter is 12.5 mm (0.5 in). The surface of the load fixture can be rough, smooth, curved or machined, etc.

A3.1.4 Pistons are also available in several different sizes or load ranges. The median range of the piston recommended for selection is close to the predicted tensile strength of the coating to be tested. This will minimize errors in the assumed coating strength.

A3.1.5 There are several models of control modules that can be used. The digital model includes a computer with wireless real-time transmission options such as Bluetooth and a PC to transmit pull tests, LabVIEW creation software, USB camera for photo recording of pull tests, and the ability to generate reports.

A3.1.6 The compressed air source can be (1) a self-brought minimum cylinder for easy carrying, (2) purchased (bottled) air, or (3) air from an automated pump.

A3.2 Test process:

A3.2.1 Refer to the general process described in sections 6 and 7. This section describes the special process of the Model IV tester.

A3.2.2 Attach the load fixture to the coating according to the epoxy manufacturer’s instructions and re-define the area to be tested using a cut-off ring or adhesive film. On larger load clamps, use a pointed cotton applicator or rag to simply clean excess epoxy.

A3.2.3 Place the piston on top of the load fixture and slowly insert the reaction material (piston tip) into the load fixture.

A3.2.4 Connect appropriate pneumatic hoses to ensure that the air supply to the control module reads at least 0.67 Mpa (100 psi) on the supply meter. Set piston pressure gauge/display to zero.

A3.2.5 Ensure that the speed valve is closed (clockwise off), then press and secure the start button. Slowly open the speed valve (counterclockwise), monitor the piston pressure gauge/display, the pressure increase rate is less than 1 MPa/s (100 psi/s), and ensure that the test is completed within 100 s. When the load fixture is separated from the surface or the required pressure is reached, loosen the start button.

A3.2.6 Open the speed valve a little wider (counterclockwise) to release the residual pressure so that the load fixture can be removed from the piston and ready for the next experiment.

A3.2.7 Record the maximum pressure obtained and the piston used. This step is done automatically using conversion charts to convert the maximum piston pressure to the coating tensile strength, or special test parameters set by the software.

ASTM D 4541-2009 Determination of Tensile Strength of Coatings by Portable Adhesion Tester

A3.2.8 Record test sites with photographs, using alternative USB cameras if possible/necessary.

(a)

FIG. A3.1 Photo (a) and piston diagram (b) of Model IV, self-aligned pull tester

A4. Self-aligned Adhesion Tester, Model V (Test Method E)

A4.1 Instrument:

A4.1.1 This is a self-aligning portable tester, as shown in Figure A4.1.12,10.

Note A4.1 — Precision data for the model III instrument are shown in Table 6, and the instrument used is shown in Figure A4.1 “Manual”.

A4.1.2 The tester uses a self-aligned spherical load jig head. The load produces a uniform tensile force on the surface to be measured, ensuring a vertically balanced pull. The diameter of the standard load fixture is 20 mm (0.78 in.), which is equal to the diameter of the driving hole location area. In this way, the pressure generated by the load fixture is equal to the pressure generated by the actuator and is directly transmitted to the pressure gauge. The tester automatically calculates 50 mm (1.97 in.) load clamps, usually customized in sizes of 10 and 14 mm (0.39 in.). And 0.55 in.).

A4.1.3 The components of the instrument are: a load fixture with a diameter of 10 to 50 mm (0.39 and 1.97 in., respectively), a hydraulic actuator to apply the load to the load fixture, a pressure gauge with LCD display and a hydraulic pump.

A4.1.4 The gauge shows the maximum force and pulling speed.

A4.1.5 The tester is equipped with accessories for surface treatment on plastic, metal and wood. Specific load jig, the typical size used for bending surface is 10mm(0.39 in.), and the size is 14mm (0.55in.) when the required pullout pressure is higher

12 To the knowledge of the Commission, the only supplier of the Burslatel tester is Defisk Corporation, 802 Proctor Avenue, Ogdensburg, NY 13669, USA.
A4.2 Test process:

A4.2.1 Refer to the general process described in sections 6 and 7. This section describes the special process of the model V tester.

A4.2.2 Ensure that the pressure release valve on the pump is fully open. Push the handle of the booster completely under the booster device.

A4.2.3 Place the driving device on the top of the load fixture and connect the quick joint to the load fixture. Close the pressure relief valve on the pump. Select the appropriate load fixture on the display and press the zero button.

A4.2.4 Use the pumping handle to fill the pump until the display reading reaches the filling pressure specified in the instruction manual. The slurry pump handle is turned to a vertical position and then a round trip is completed at the same speed indicated as no less than 1 MPa/s (150 psi/s) until the actuator pulls the load fixture away from the surface.

ASTM D 4541-2009 Determination of Tensile Strength of Coatings by Portable Adhesion Tester

A4.2.5 After pulling away, open the pressure release valve on the pump to release the pressure. The display will remain at the maximum pressure reading. Record the pullout pressure to the tester’s memory and mark the load fixture for future mass analysis.

A4.2.6 One type of the tester is equipped with an automatic hydraulic pump.

(a)

(b)

FIG.A4.1 Photo (a) and schematic diagram (b) of Model V, self-aligned pull tester

A5. Self-aligned Adhesion Tester, Model VI (Test method F)

A5.1 Instrument s:

A5.1.1 This is a self-aligning portable tester, as shown in Figure A5.1. .

Note A4.1 — Precision data for model III instruments are shown in Table 6, and the instruments used are shown in Figure A5.1. As shown.

A5.1.2 Self-aligning test head uses four independent operating feet to ensure that the tensile stress on the load fixture is evenly distributed in the shape of the substrate or the Angle of the surface of the load fixture. See Figure A5.1.

A5.1.3 The instrument consists of the crank handle pulling mechanism of hydraulic cable mechanism, 6.3 kN self-aligning test head and load fixture.

A5.1.4 The diameter of the load fixture ranges from 2.8-70 mm. Connect a load fixture with a diameter of 20 mm to the test head using a quick release connector. Other models of load clamps are threaded and connected to the self-aligned test head using an adapter. Load jig with a diameter of 2.8-5.7 mm using a miniature self-aligned test head at a speed of 1 kN.

A5.1.5 The force applied to the load jig as indicated on a hydraulic pressure gauge with a drag indicator is the maximum reading of the load jig off the surface. There are two scales on the pressure gauge: PSI and MPa.

A5.2 Test process:

A5.2.1 Refer to the general process described in sections 6 and 7. This section describes the special process of the model VI tester.

A5.2.2 Open the valve at the bottom of the cylinder to ensure that the pressure of the pull-off mechanism is released. Set the drag indicator to zero, in line with the gauge pointer.

A5.2.3 Connect the self-aligned test head to the hydraulic cable mechanism using the quick release connector on the side of the test head. Turn the crank handle to the starting position and push the head to the plane so that the four pistons of the self-aligning head are aligned.

A5.2.4 Place the relevant support ring on the load fixture. Support rings are not required for load clamps with a diameter of 25 mm, 50 mm or 70 mm, or an area of 50 mm2.

A5.2.5 Connect the test head to the load fixture directly or using an adapter, as appropriate. Close the valve.

A5.2.6 Ensure that the hydraulic cable mechanism is not strained. Hold the pull-off mechanism in one hand, and operate the crank evenly and regularly with the other hand to ensure that the applied force is uniform until the required value is reached or broken.

A5.2.7 Immediately after the pull is over, open the valve to release all residual pressure and turn the crank handle to the starting position. The instrument can be used for the next pull. A5.2.8 Record the value displayed by the drag indicator and mark the load fixture as detailed in Section 8 for further analysis.

(a)

(b)

FIG. A5.1 A4.1 Model VI photo (a) and schematic diagram (b), self-aligned pull tester

Appendix

(Non-mandatory information) X1. Stress calculation

X1.1 If the applied stress is uniformly distributed at the critical point of fracture, the calculated stress is the tensile strength of a similar hardness coating system. If the peak-to-mean ratio of the continuous stress distribution is known, the average tensile strength is approximated by:

U=XRo (X1.1)

Among them:

U = average tensile strength, representing the maximum force that can be applied to a given surface area, psi (MPa),

X = tensile strength measured in the field, calculated using 8.2,

psi (MPa), and

Ro = peak-to-mean stress ratio of the aligned system.

It should be noted that these differences in tensile strength do not necessarily mean that the values are all wrong; The values measured in the field simply reflect the true characteristics of the coating system used with similar concentric hardness systems.

X1.2 An error occurs if the instrument is not aligned with the normal direction of the surface. The approximate stress peak mean calibration ratio is:

R=Ro (1+ 0.14az /d) (X1.2)

ASTM D 4541-2009 Determination of Tensile Strength of Coatings by Portable Adhesion Tester

Among them:

z = the point from the surface to the first frame or actuation mechanism to generate force and reaction force, in. (mm),

d = diameter of load fixture, in. (mm),

a = the Angle of the deviation, the degree (below 5), and

R = maximum ratio of mean value of stress peak of deviation hardness system.

Overview of Changes

The D01 Committee indicates the location of selective changes in this standard from the previous version (D541-02) that would affect the use of the standard. (Licensed on 1 February 2009)

(1) The test scope is changed to describe the type of substrate used in this test method.

(2) Test method A is abolished and test method F and Appendix F are added.

(3) Part 10 — Revised descriptions of precision and bias based on joint statement research.

(4) Changes in versions throughout the file.