ISO/TC 206/WG 7 - Monolithic ceramics/Physical and thermal properties

This document specifies the test method for the determination of thermal diffusivity from room temperature to at least 1 700 K by the flash method for homogeneous monolithic ceramics with porosity less than 10 %. Flash methods, like laser flash, are applicable to homogeneous isotropic materials with thermal diffusivity values ranging from 0,1 to 1 000 mm2 s-1 within the temperature range from approximately 100 K to 2 300 K. The method described in Annex G describes how to estimate, on the basis of the thermal diffusivity test, the specific heat capacity and the thermal conductivity of homogeneous monolithic ceramics with porosity less than 10 %.

This document specifies the test method for measuring the crystalline quality of single-crystal thin film (wafer) using the XRD method with parallel X-ray beam. This document is applicable to all of the single-crystal thin film (wafer) as bulk or epitaxial layer structure.

This document specifies methods for the determination of the apparent solid density, bulk density, apparent porosity and geometric bulk density of fine ceramics, including all ceramic matrix composites. Two methods are described and are designated as Methods A and B, as follows: — Method A: Determination of bulk density, apparent solid density and apparent porosity by liquid displacement (Archimedes' method). NOTE 1 This method is not appropriate for the determination of an apparent porosity greater than 10 %. For materials with higher porosity, the accuracy of the measurement might not be satisfactory. This method might also not give a satisfactory open porosity result if it is less than 0,5 %. NOTE 2 This method is also not suitable for materials which are known to have an average pore size of greater than 600 µm. — Method B: Determination of bulk density only, by measurement of geometric dimensions and mass.

ISO 19618:2017 specifies a method used for the determination of normal spectral emissivity and normal quasi-total emissivity of fine ceramics using blackbody reference with a Fourier transform infrared spectrometer (FTIR) at elevated temperatures. This method is applicable to fine ceramics, ceramic matrix composites, and continuous fibre-reinforced ceramic matrix composites which are opaque and highly non-reflective at wavelengths between 1,67 μm and 25 μm. The applicable temperature range is approximately 350 K to 1 100 K.

ISO 17562:2016 specifies a method for the determination of the linear thermal expansion and the linear thermal expansion coefficient of monolithic ceramics from near liquid nitrogen temperature up to a maximum temperature of 2 000 °C.

ISO 18550:2016 specifies a test method for determining macro-heterogeneities within the microstructure of fine ceramics that are above a certain size within the volume of the material and affect materials mechanical strength properties. This method is limited to fine ceramics with a porosity of less than 10 vol% and that are transparent for visible light in the form of a thin specimen.

ISO 13383-2:2012 specifies a manual method of making measurements for the determination of the volume fraction of major phases in fine ceramics (advanced ceramics, advanced technical ceramics) using micrographs of polished and etched sections, overlaying a square grid of lines, and counting the number of intersections lying over each phase. The method applies to ceramics with one or more distinct secondary phases, such as found in Al2O3/ZrO2, Si/SiC, or Al2O3/SiCw. If the test material contains discrete pores, these are to be treated as a secondary phase for the purpose of this method, provided that there is no evidence of grain pluck-out during polishing being confused with genuine pores.

ISO 13383-1:2012 describes manual methods of making measurements for the determination of grain size of fine ceramics (advanced ceramics, advanced technical ceramics) using photomicrographs of polished and etched test pieces. The methods described in ISO 13383-1:2012 do not yield the true mean grain diameter, but a somewhat smaller parameter depending on the method applied to analyse a two-dimensional section. The relationship to true grain dimensions depends on the grain shape and the degree of microstructural anisotropy. ISO 13383-1:2012 contains two principal methods, A and B. Method A is the mean linear intercept technique. Method A1 applies to single-phase ceramics, and to ceramics with a principal crystalline phase and a glassy grain-boundary phase of less than about 5 % by volume for which intercept counting suffices. Method A2 applies to ceramics with more than about 5 % by volume of pores or secondary phases, or ceramics with more than one major crystalline phase where individual intercept lengths are measured, which can optionally be used to create a size distribution. This latter method allows the pores or phases to be distinguished and the mean linear intercept size for each to be calculated separately. Method B is the mean equivalent circle diameter method, which applies to any type of ceramic with or without a secondary phase. This method may also be employed for determining grain aspect ratio and a size distribution.

ISO 17092:2005 describes the test method for determining the corrosion resistance of fine ceramics in acid and alkaline solutions, such as sulfuric acid and sodium hydroxide. This International Standard is designed to provide an assessment of the mass changes and dimensional changes of test specimens following the corrosion test immersed in the corrosive liquids, and to assess whether corrosion has a significant effect on the subsequent strength. This test method may be used for development of materials, quality control, characterization, and design-data generation purposes.

ISO 20509:2003 describes the method of test for determining the oxidation resistance of non-oxide monolithic ceramics, such as silicon nitride, sialon and silicon carbide at high temperatures. This International Standard is designed to provide an assessment of the mass and dimensional changes of test pieces following oxidation at high temperature in an oxidizing atmosphere, and to assess whether oxidation has a significant effect on the subsequent strength. This test method may be used for materials development, quality control, characterization, and design data generation purposes.

ISO 18754:2013 specifies methods for the determination of the apparent solid density, bulk density, apparent density and geometric bulk density of fine ceramics.

ISO 18755:2005 specifies the test method for the determination of thermal diffusivity from room temperature to 1700 K by the laser flash method for homogeneous monolithic ceramics with porosity less than 10 %.

ISO 18754:2003 specifies a method for the determination of the apparent solid density, bulk density and apparent porosity of fine ceramics. This method is not appropriate for the determination of an apparent porosity greater than 10 %. For materials with higher porosity, the accuracy of the measurement may not be satisfactory. The method may also not give satisfactory open porosity result if it is less than 0,5 %.