ISO 19674-2017 PDF

Full title and description

Fine ceramics (advanced ceramics, advanced technical ceramics) — Methods of test for ceramic coatings — Determination of internal stress in ceramic coatings by application of the Stoney formula. ISO 19674:2017 specifies a laboratory method to determine the internal (residual) stress in thin ceramic coatings by measuring the curvature (radius of curvature) of coated isotropic strips or discs and applying the Stoney formula to calculate stress from the measured curvature and known substrate/coating properties.

Abstract

ISO 19674:2017 provides a standardized procedure for measuring the internal stress of thin ceramic coatings using curvature measurements and the Stoney equation. The standard covers specimen preparation (single-face coatings on isotropic substrates), curvature measurement techniques, required input data (substrate thickness, elastic moduli, coating thickness), calculation steps, assumptions and limitations of the Stoney approach, and recommended reporting of results and uncertainties.

General information

• Status: Withdrawn (superseded).
• Publication date: 1 September 2017.
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 81.060.30 (Fine ceramics).
• Edition / version: Edition 1 (2017).
• Number of pages: 10 pages.

Scope

This document specifies a method for the determination of the internal stress in thin ceramic coatings. The internal stress is determined by application of the Stoney formula to the results obtained from measurement of the radius of curvature of isotropic strips or discs with single-face coating. The standard states the required specimen geometry and material information, the measurement procedure for curvature, the formula and calculation procedure, and the limitations and assumptions inherent to the method (for example, that coating thickness is small relative to substrate thickness and that elastic properties are known and applicable).

Key topics and requirements

• Application of the Stoney formula to convert measured curvature (radius) into in-plane internal stress in the coating.
• Specimen requirements: isotropic substrate, single-face coating, defined strip or disc geometry and dimensions.
• Measurement methods for curvature (optical, profilometric or interferometric approaches) and best-practice measurement techniques.
• Required material input data: substrate thickness, coating thickness, elastic moduli and Poisson’s ratios (where relevant) for substrate and coating.
• Assumptions and limitations of the Stoney approach (thin-coating approximation, negligible coating bending stiffness compared with substrate, small deflections, elastic behaviour).
• Calculation steps, unit conventions and recommended presentation of numerical results.
• Guidance on uncertainty estimation and reporting of measurement conditions and sample preparation.

Typical use and users

Laboratories and researchers characterizing thin ceramic coatings, coating and advanced ceramics manufacturers performing quality control and product development, materials scientists studying residual stresses in coatings, and component manufacturers assessing coating performance and reliability. Typical applications include R&D evaluation of deposition processes, screening for stress-induced delamination or cracking, and comparative testing of coating recipes.

Related standards

Superseded by a later edition (ISO 19674:2025). Related documents include other ISO/TC 206 standards and test methods for fine ceramics and ceramic coatings, and more general standards and guidance on thin-film measurement, curvature measurement techniques and residual stress evaluation methods. Users often consult complementary standards on substrate characterization, coating thickness measurement and instrumentation/uncertainty reporting when applying this method.

Keywords

fine ceramics, ceramic coatings, internal stress, residual stress, Stoney formula, curvature measurement, thin films, coating test methods, ISO 19674

FAQ

Q: What is this standard?

A: ISO 19674:2017 is an ISO test method that defines how to determine internal (residual) stress in thin ceramic coatings by measuring curvature of coated strips or discs and applying the Stoney formula to compute in-plane stress.

Q: What does it cover?

A: It covers specimen geometry and preparation (single-face coatings on isotropic substrates), curvature measurement methods, required elastic and geometric input data, the Stoney calculation procedure, assumptions and limitations of the method, and recommendations for reporting results and uncertainty.

Q: Who typically uses it?

A: Materials and coatings laboratories, ceramic and coating manufacturers, quality-control engineers, and researchers investigating thin-film stresses and coating reliability.

Q: Is it current or superseded?

A: ISO 19674:2017 is withdrawn and has been superseded by a later edition (ISO 19674:2025). The original publication date was 1 September 2017; the revised edition was published in 2025, and the 2017 edition was formally withdrawn when the new edition was released.

Q: Is it part of a series?

A: Yes. It is part of the body of ISO standards on fine ceramics (work of ISO/TC 206) and is associated with other test methods and guidance documents addressing ceramic materials, coatings and thin-film characterization.

Q: What are the key keywords?

A: Fine ceramics, ceramic coatings, internal stress, residual stress, Stoney formula, curvature measurement, thin-film testing, ISO 19674.