BS EN 17393:2020 pdf download.Thermal spraying —Tubular coating tensile test.
This document specifies the procedure for the determination of coating strength, and hence of cohesivestrength in a tubular coating tensile test.
The test is intended to determine the tensile coating strength parallel to the spray layers (normal to thespray direction) and to identify differences in particle cohesion quality, as caused by defects as internaldelamination at cracks or oxides between the spray particles or splats.
The tubular coating tensile test is suitable for sprayed coatings deposited using metallic materials (notcarbides and ceramics).
The tubular coating tensile test is not suitable for fused sprayed coatings deposited using self-fluxingalloys.
The test supports quality assurance and is intended to be applied for the purpose of coatingoptimization by identifying the influences of coating parameters and spray materials on the coatings’squality.Furthermore, the coating in particular for cold sprayed coatings can be compared with thecharacteristics of similar solid materials and the coating’s quality can be assessed.
This test is not recommended for thin coatings (coating thickness <500 um), since massive scattering ofresults is to be expected here. Due to the size of the specimen, it is particularly suitable to apply thetubular coating tensile test for coating processes that use a concentrated spray jet and a highly focusedspray spot, as in the case of cold spraying, high velocity flame spraying (HVOF) or plasma spraying.Applying the tubular coating tensile test for coating processes that use a broad spray jet, such as flamespraying and arc spraying may require special spraying measures,e.g. the use of a template to ensure anearly vertical impingement angle.
2Normative references
The following documents are referred to in the text in such a way that some or all of their contentconstitutes requirements of this document. For dated references,only the edition cited applies.Forundated references, the latest edition of the referenced document (including any amendments) applies.EN ISO 14916,Thermal spraying -Determination of tensile adhesive strength (ISo 14916)
EN ISO 14917, Thermal spraying -Terminology, classification (ISo 14917)
EN ISO 7500-1:2018,Metallic materials —Calibration and verification of static uniaxial testingmachines — Part 1: Tension/compression testing machines — Calibration and verification of the force-measuring system (1sO 7500-1:20i8)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN ISO 14917 and the followingapply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:一IEC Electropedia: available at http://www.electropedia.org/
-ISo online browsing platform: available at https://www.iso.org/obp
3.1 tensile coating strengthRm,TCT tensile strength of the coating determined in a tension test, parallel to the coating layers (normal to thespray direction), which is calculated from the quotient of the maximum load Fm and the coating’s cross-section
4Testing equipment
A tensile testing machine in accordance with EN ISO 7500-1:2018,class 1， shall be used having asuitable clamping system to ensure concentric clamping and loading of the specimens, see Figure 1.
5 Specimens
5.1 Shape of base samples
The base samples are made of aluminium or non alloy steel.Their outer dimensions shall be equal tothose of the specimens used in the determination of tensile adhesive strength according toEN ISO 14916 (diameter: 25 mm or 40 mm), and they have a central bore (6 mm through bore) forfixation, see Figure 2.Rounding or chamfering the front face is not permitted.
5.2 Preparation of the specimen to be sprayed
Install the base samples in the fixture, see Figure 3, and adjust them to the maximum common diameter(tolerance ±0,02 mm) using a lathe.A uniform surface quality Rz of about 40 um shall be achieved.Thistype of levelling is important, because otherwise a discrepancy between the two cylinders wouldsignificantly weaken the coating that is to be applied. The diameter that is reached, Dj which isrepresented in the drawing as the outer diameter of the specimen (underneath the coating), shall berecorded.BS EN 17393 pdf download.