ISO 21814:2019

Overview

ISO 21814:2019 specifies standardized methods for chemical analysis of aluminium nitride (AlN) powders used as raw materials for fine ceramics (advanced/technical ceramics). The standard defines how to prepare test samples, report analytical values, and determine a broad set of elemental and impurity contents so results are reproducible and suitable for quality control, materials characterization and regulatory or customer specifications.

Keywords: ISO 21814, aluminium nitride powders, chemical analysis, fine ceramics, quality control, ICP‑OES, inert gas fusion

Key topics and technical requirements

• Scope of analytes: aluminium, total nitrogen, boron, calcium, copper, iron, magnesium, manganese, molybdenum, nickel, potassium, silicon, sodium, titanium, tungsten, vanadium, zinc, zirconium, carbon, chlorine, fluorine and oxygen.
• Sample preparation: guidance on sampling, drying and weighing to obtain representative, traceable test samples prior to analysis.
• Aluminium determination: two accepted approaches - an acid pressure decomposition + CyDTA–zinc back titration method or acid digestion + ICP‑OES.
• Total nitrogen: options include acid pressure decomposition → distillation → acidimetric titration, direct decomposition → distillation → titration, or inert gas fusion with thermal conductivity detection.
• Trace elements (B, Ca, Cu, Fe, Mg, Mn, Mo, Ni, K, Si, Na, Ti, W, V, Zn, Zr): determined mainly by acid digestion or acid pressure decomposition followed by ICP‑OES.
• Alkali metals (Na, K): can also be measured by flame emission or atomic absorption spectrometry after acid pressure decomposition.
• Oxygen and carbon: oxygen by inert gas fusion with IR absorption, carbon by combustion with IR absorption or combustion‑conductometry.
• Halogens (Cl, F): determined by pyrohydrolysis followed by ion chromatography or spectrophotometry.
• Reporting and quality checks: number of analyses, blank tests, recovery checks and expression of analytical values are specified to ensure data validity.

Applications and users

• Ceramic manufacturers and raw material suppliers use ISO 21814 for incoming material inspection and supplier qualification.
• Analytical and testing laboratories adopt the methods for routine compositional analysis and inter-laboratory comparability.
• R&D teams in electronics, thermal management and power devices use it for materials characterization during formulation and process optimization.
• Quality assurance and certification bodies rely on standardized methods for compliance and product specifications.

Keywords: materials characterization, quality assurance, analytical laboratory methods

Related standards

• Labs using ISO 21814 commonly reference ISO methods for sampling, calibration and instrumentation standards (e.g., ICP‑OES, combustion analyzers, inert gas fusion) and national accreditation requirements (e.g., ISO/IEC 17025) to support method validity and traceability.