ISO/TC 206/WG 10 - Coatings

This document specifies a method for testing the wear resistance and friction coefficient for fine ceramic thin films in dry and high-humidity environments, where such films have a thickness of up to approximately 1 µm and are deposited on a substrate or a base, including a thin substrate or a very thin organic polymer film base.

This document specifies the procedure for measuring the spectral reflectance of fine ceramic thin films in an environment with variable relative humidity by using a general-purpose spectrophotometer.

This document specifies a test method for determining thermal expansion coefficient up to 2 300 K and the residual stress of chemical vapour deposition (CVD) ceramic coatings (thickness > 0,03 mm) at room temperature. Procedures for test piece preparation, test modes, heat rate, data collection, property calculations and reporting procedures are given. This document applies to CVD ceramic coatings on metal or ceramic substrates. This test method can be used for material research, quality control, characterization and design data-generation purposes.

This document specifies the testing method for the determination of the bonding strength of ceramic coatings at ambient temperature by the compression tests on the cross-joined test pieces. Methods for test piece preparation, test mode and rate, data collection and reporting procedures are addressed. This document applies primarily to any ceramic coatings, thick or thin, bonded onto substrates of various materials. The test method described can be used for materials research, quality control, characterization and design data generation purposes.

This document specifies a testing method for determining the density of thick ceramic coatings at ambient temperature using the Archimedes method. Methods for test piece preparation, test modes, data collection and density calculation are addressed. This document applies to ceramic coatings with a thickness > 0,1 mm including thermal barrier coatings, wear-resistance coatings and other thick coatings on metal or ceramic substrates.

ISO 19674:2017 specifies a method for the determination of the internal stress in thin ceramic coatings by application of the Stoney formula to the results obtained from measurement of the radius of curvature of coated strips or discs.

ISO 19606:2017 describes a method to evaluate the adequateness of a probe tip for fine-ceramic thin-film surface roughness measurements by atomic force microscopy, of surfaces with an arithmetical mean roughness, Ra, in the range of about 1 nm to 30 nm and a mean width of roughness profile elements, RSm, in the range of about 0,04 μm to 2,5 μm.

ISO 20343:2017 specifies a method of test for determining the elastic modulus of thick ceramic monolayer coatings (thickness > 0,03 mm) at elevated temperatures, using the impulse excitation method. Procedures for test piece preparation, test modes and rates (load rate or displacement), data collection, and reporting procedures are given. ISO 20343:2017 applies primarily to brittle ceramic coatings on ceramic or metal substrates. This test method can be used for material research, quality control, and characterization and design data-generation purposes.

ISO 19603:2016 specifies a testing method for determining the elastic modulus and bending strength of thick ceramic coatings at ambient temperature by three-point bending tests. Procedures for test piece preparation, test modes and load rates, data collection and reporting are given. ISO 19603:2016 applies to thick, brittle coatings on metal or ceramic substrates. This test method can be used for material research, quality control, characterization and design data-generation purposes.

ISO 17861:2014 specifies a measurement method of spectral transmittance of fine ceramics thin films under humid condition. It provides test methods that will easily and accurately evaluate changes in optical properties of fine ceramic coatings in a humid atmosphere due to water adsorption.

ISO 14604:2012 describes a method of measuring the fracture strain of ceramic coatings by means of uniaxial tension or compression tests coupled with acoustic emission to monitor the onset of cracking of the coating. Tensile or compressive strains can also be applied by flexure using four-point bending. Measurements can be made in favourable cases at elevated temperatures as well as at room temperature.

ISO 26423:2009 specifies a method for the determination of the thickness of ceramic coatings by a crater grinding method, which includes the grinding of a spherical cavity and subsequent microscopic examination of the crater. Because of the uncertainty introduced into the measurement of crater dimensions, the test is not suitable for use where the surface roughness of the coating and/or substrate exceeds 20 % of the coating thickness.

ISO 26424:2008 specifies a method for measuring the abrasive wear rate of ceramic coatings by means of a micro-scale abrasion wear test based on the well-known crater-grinding technique used for coating thickness determination in ISO 26423. The method can provide data on both coating and substrate wear rates, either by performing two separate tests or by careful analysis of the data from a single test series. The method can be applied to samples with planar or non-planar surfaces, but the results analysis described in the text applies only to flat samples. For non-planar samples, a more complicated analysis, possibly requiring the use of numerical methods, is required.

ISO 18452:2005 specifies a method for the determination of the film thickness of a fine ceramic film and ceramic coatings by a contact-probe profilometer. The method is suitable for film thicknesses in the range of 10 nm to 10 000 nm.

ISO 20502:2005 describes a method of testing ceramic coatings by scratching with a diamond stylus. During a test, either a constant or increasing force normal to the surface under test is applied to the stylus, so as to promote adhesive and/or cohesive failure of the coating-substrate system. The test method is suitable for evaluating ceramic coatings up to a thickness of 20 micrometres and might also be suitable for evaluating other coating types and thicknesses.

ISO 20508:2003 specifies a test method for determining the visible light transmittance of a transparent coating material, e.g., the transparent electrode for display devices, in which a fine ceramic thin film is coated on to a substrate. ISO 20508:2003 is not applicable to deliberately coloured, uneven or non-parallel faced test pieces. A translucent medium is not included in this International Standard.

ISO 26443:2008 specifies a method for the qualitative evaluation of the adhesion of ceramic coatings up to 20 µm thick by indentation with a Rockwell diamond indenter. The formation of cracks after indentation may also reveal cohesive failure. The indentations are made with a Rockwell hardness test instrument. The method described may also be suitable for evaluating the adhesion of metallic coatings. The test is not suitable for elastic coatings on hard substrates.