ISO 21068-4-2024 PDF

Full title and description

ISO 21068-4:2024 — Chemical analysis of raw materials and refractory products containing silicon‑carbide, silicon‑nitride, silicon‑oxynitride and sialon — Part 4: XRD methods. This part specifies X‑ray diffraction (XRD) methods (Bragg–Brentano geometry) for qualitative and quantitative determination of mineralogical phases in nitride and oxy‑nitride bonded silicon‑carbide refractory products, with procedures for the main nitride/oxynitride phases encountered.

Abstract

This document describes sample preparation, general principles for qualitative and quantitative phase analysis using a Bragg–Brentano diffractometer and specific quantitative procedures (including refinement approaches based on total nitrogen content) for α‑Si3N4, β‑Si3N4, Si2ON2, AlN and β’‑SiAlON in silicon‑carbide refractory products. It notes that the refinement procedures require total nitrogen values determined in accordance with ISO 21068‑3.

General information

• Status: Published.
• Publication date: June 2024 (published 2024‑06).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 81.080 — Refractories / chemical analysis of refractory materials.
• Edition / version: Edition 1 (2024).
• Number of pages: 11 pages (ISO published text).

Scope

Applies to chemical/mineralogical analysis of raw materials and refractory products that contain silicon carbide and are bonded with nitrides or oxy‑nitrides (Si3N4, Si2ON2, SiAlON types, AlN, etc.). The standard sets out XRD‑based methods for identifying and quantifying the mineralogical phases typically present in nitride and oxy‑nitride bonded SiC refractories, and gives sample preparation guidance and refinement procedures for quantitative phase analysis (the latter using total nitrogen input from ISO 21068‑3).

Key topics and requirements

• Sample preparation and handling for XRD analysis of nitride/oxy‑nitride bonded SiC refractories.
• Use of Bragg–Brentano diffractometer configurations for phase identification and quantification.
• Procedures for qualitative phase analysis (phase ID and peak interpretation).
• Quantitative determination methods for α‑Si3N4, β‑Si3N4, Si2ON2, AlN and β’‑SiAlON (including refinement strategies).
• Requirement to use total nitrogen results (from ISO 21068‑3) as input for certain refinement/quantification procedures.
• General recommendations on reporting results and limits of applicability (typical refractory matrices and phase ranges covered).

Typical use and users

Used by industrial and research laboratories performing chemical/mineralogical characterization and quality control of silicon‑carbide based refractories (especially nitride‑bonded and oxy‑nitride systems). Typical users include refractory manufacturers, materials laboratories, quality assurance personnel, process engineers, and academic researchers studying SiC/Si3N4/SiAlON refractory systems.

Related standards

ISO 21068 is a multipart series; relevant parts include: ISO 21068‑1 (general information, terminology and sample preparation), ISO 21068‑2 (determination of volatile components, carbon, SiC and silica), and ISO 21068‑3 (determination of total nitrogen, oxygen and metallic/oxidic constituents). These parts form the analytical framework that complements the XRD methods in Part 4.

Keywords

SiC refractories; silicon‑nitride; SiAlON; oxy‑nitride; XRD methods; Bragg–Brentano; phase quantification; α‑Si3N4; β‑Si3N4; Si2ON2; AlN; β’‑SiAlON; ISO 21068 series; total nitrogen.

FAQ

Q: What is this standard?

A: ISO 21068‑4:2024 is the ISO document that specifies X‑ray diffraction (XRD) methods for identifying and quantifying mineralogical phases in nitride and oxy‑nitride bonded silicon‑carbide refractory products.

Q: What does it cover?

A: It covers sample preparation for XRD, Bragg–Brentano measurement practices, qualitative phase identification and quantitative phase‑analysis procedures (including specific recipes for α‑ and β‑Si3N4, Si2ON2, AlN and β’‑SiAlON). For some quantitative refinements the standard requires total nitrogen data provided by ISO 21068‑3.

Q: Who typically uses it?

A: Refractory manufacturers, materials testing and R&D laboratories, QA/QC engineers, and academics working on silicon‑carbide and nitride/oxy‑nitride refractory systems.

Q: Is it current or superseded?

A: ISO 21068‑4:2024 is a current, published International Standard (published June 2024). It is the active Part 4 in the ISO 21068 series.

Q: Is it part of a series?

A: Yes — it is Part 4 of the ISO 21068 series. Complementary parts include ISO 21068‑1 (general information/sample preparation), ISO 21068‑2 (volatile components, carbon, SiC, silica) and ISO 21068‑3 (total nitrogen/oxygen and metallic/oxidic constituents). Use the parts together for a complete chemical and mineralogical analysis workflow.

Q: What are the key keywords?

A: XRD, Bragg–Brentano, silicon carbide, silicon nitride, SiAlON, Si2ON2, AlN, phase quantification, refractory analysis, ISO 21068.