Standards Development

Scope

This document specifies a thermogravimetric analysis (TGA) method for determining the solid content of photocurable ceramic slurry used in vat photopolymerization additive manufacturing.

Using TGA, the solid content is determined by measuring the mass change of a ceramic slurry sample as a function of temperature under controlled thermal conditions. This enables differentiation between thermally stable inorganic residues and organic constituents that are combusted or volatilized. This document describes the principle of the method, as well as sampling, sample preparation, test procedure, calculation, and reporting of solid content.

This document aims to evaluate the solid content by using TGA, which is an important parameter influencing various properties of photocurable ceramic slurry used in additive manufacturing, as specified in ISO/ASTM 52940. TGA of ceramic slurry also provides additional information for establishing appropriate temperature range for the debinding or sintering processes following additive manufacturing. Furthermore, it is applicable for evaluating the dispersion uniformity of ceramic powder in photocurable resins.

This document does not specify acceptance criteria for solid content values, nor does it address process optimization, printing performance, dimensional accuracy, or end-use properties of ceramic parts. This document does not deal with safety aspects.

Purpose

Among the key characteristics of photocurable ceramic slurries used in vat photopolymerization, solid content is a fundamental parameter that directly influences rheological behaviour, curing efficiency, dimensional stability, and densification during subsequent debinding and sintering processes. Despite its importance, there is currently no widely harmonized or standardized method for accurately determining the solid content of photocurable ceramic slurries. Conventional methods, such as loss-onignition techniques, often lack sufficient accuracy due to the complex composition of these materials, which typically include volatile organic components, polymerizable resins, and thermally stable inorganic powders. As a result, these methods can lead to inconsistent results and limited comparability across laboratories and industrial practices. Thermogravimetric analysis (TGA) provides a reliable and reproducible approach for distinguishing between organic constituents that are volatilized or decomposed and inorganic residues that remain after thermal treatment. By measuring mass change as a function of temperature under controlled conditions, TGA enables a more accurate and consistent determination of solid content compared to conventional methods. The establishment of a standardized TGA-based test method will improve the consistency, reliability, and comparability of measurement results across different organizations. This will support enhanced material characterization, enable more effective quality control in manufacturing processes, and facilitate the development and optimization of photocurable ceramic slurries for additive manufacturing applications. Furthermore, the method provides additional information on the thermal behaviour of ceramic slurries, which can assist in defining appropriate temperature ranges for debinding and sintering. It can also be applied to evaluate the dispersion uniformity of ceramic particles within the resin matrix, thereby supporting improved process control and product performance. In this context, this document specifies a standardized procedure for determining the solid content of photocurable ceramic slurries using thermogravimetric analysis, thereby addressing an important gap in existing standards for additive manufacturing materials. (Please use this field or attach an annex)