Overview
SIST EN 24501:2000 specifies a photometric peroxide method for the accurate determination of titanium content in hardmetals. This standard, aligned with ISO 4501:1978, is designed for carbide and binder metal powder mixtures free of lubricants, as well as all grades of presintered or sintered hardmetals with titanium levels exceeding 0.2% by mass. The method relies on the formation of a yellow pertitanic acid complex, whose absorbance is measured spectrophotometrically, providing a reliable assessment of titanium concentrations in these materials.
Key Topics
- Scope of Application: Applicable to hardmetal powders and sintered products where titanium exceeds 0.2% (m/m).
- Analytical Principle: Formation of a colored pertitanic acid complex detected by spectrophotometry at approximately 420 nm wavelength.
- Sample Preparation: Samples are crushed to a fine powder passing a 0.18 mm sieve, ensuring uniformity and accuracy.
- Reagents and Apparatus: Use of ammonium hydrogen fluoride, ammonium sulphate, sodium disulphite, citric acid solution, and hydrogen peroxide with ordinary laboratory spectrophotometers or filter photometers.
- Interferences and Corrections: The method accounts for interfering elements such as vanadium and molybdenum, which form colored complexes that can affect absorbance readings; corrections and elimination procedures are detailed.
- Calibration: Calibration curves are created using standard titanium solutions prepared from high-purity titanium metal or titanium dioxide, ensuring precise quantification.
- Result Expression: Titanium content is calculated based on absorbance, sample mass, solution volume, and cell length, and results are reported with defined tolerances.
Applications
- Quality Control in Powder Metallurgy: Ideal for verifying titanium content in powder mixtures before sintering to maintain product consistency.
- Material Certification: Assists manufacturers and quality assurance teams in certifying the titanium percentage in hardmetal components per contractual and regulatory requirements.
- Research & Development: Enables precise monitoring of titanium concentrations for developing new carbide composites and enhanced binder formulations.
- Industrial Inspection: Supports acceptance testing and ongoing manufacturing process control in hardmetal production facilities.
Related Standards
- ISO 4501:1978 – International equivalent standard outlining the photometric peroxide method for titanium determination in hardmetals.
- EN ISO 4497 – Methods relating to metallic hard materials, potentially complementary for characterization.
- ISO 5339 – Related to the determination of other elements in powder metallurgy materials through spectrometric methods.
- ISO/TC 119 Series – Covers powder metallurgical materials and products, providing broader context for quality testing in this field.
SIST EN 24501:2000 offers a standardized, reproducible analytical method essential for industries dealing with hardmetals, ensuring accurate titanium determination that supports quality and performance in metallurgical manufacturing. Its comprehensive guidance on reagents, procedure, and interference management makes it a cornerstone document for metallurgists, analytical chemists, and quality professionals in the field of powder metallurgy.