Overview
EN 24503:1993 (ISO 4503:1978) specifies an X‑ray fluorescence (XRF) fusion method for quantitative determination of metallic elements in hardmetals and carbides. The method covers measurement of Co, Cr, Fe, Mn, Mo, Ni, Nb, Ta, Ti, W, V and Zr in carbides, mixtures of carbides and binder metals, and presintered or sintered hardmetals. The procedure uses acid dissolution or oxidation followed by fusion with a borate/barium flux to produce homogeneous disks for XRF analysis.
Note: the prompt included a scope statement about porosity and uncombined carbon that appears inconsistent with ISO 4503:1978. ISO 4503 actually addresses metallic-element analysis by XRF fusion.
Key Topics and Requirements
- Field of application: applicable to niobium, tantalum, titanium, vanadium, tungsten and zirconium carbides and their mixtures with binder metals in hardmetals.
- Analytical principle: measure characteristic X‑ray lines after converting the sample to a homogeneous borate/barium glass disk to remove particle-size and matrix effects.
- Sample preparation:
- Crush and sieve (typical sizes indicated for acid or oxidation paths).
- Two routes: acid dissolution (HF + HNO3, followed by H2SO4 and drying) or high‑temperature oxidation (700–900 °C) when appropriate.
- Fusion of oxides/sulphates with sodium tetraborate and a barium compound at ≈1100 °C; pour into preheated molds and grind disk surface.
- Reagents and apparatus: high‑purity acids (HF, HNO3, H2SO4), sodium tetraborate, barium peroxide/carbonate; X‑ray spectrometer, platinum dishes/plates, furnaces, grinding devices.
- Interferences and calibration:
- Account for line interferences (e.g., Ti and W on V).
- Use synthetic standards to prepare calibration curves representative of the hardmetal grades to be analysed.
- Recommended analytical crystals (e.g., LiF (200)); make background corrections as needed.
- Results and reporting: tolerances and rounding rules are defined; report mean of acceptable determinations and full test‑report details (reference to standard, sample ID, operations performed).
Applications and Users
- Who uses it: metallurgical laboratories, powder‑metallurgy manufacturers, hardmetal (cemented carbide) producers, quality control/assurance teams, material certification labs, and failure‑analysis specialists.
- Practical uses:
- Routine compositional control of carbide grades and binder content.
- Incoming inspection of raw powders and verification of sintered parts.
- Production process monitoring and material certification for cutting tools, wear parts and tooling components.
Related Standards
- ISO 4503 was developed by ISO/TC 119 (Powder metallurgical materials and products). Users should consult other ISO/CEN standards on hardmetals, powder metallurgy sampling, and complementary analytical methods (e.g., wet chemical analysis, ICP) when selecting the best practice for a specific application.
Keywords: EN 24503:1993, ISO 4503:1978, hardmetals, carbides, X‑ray fluorescence, fusion method, metallic elements, cobalt, tungsten, titanium, powder metallurgy, analytical method.