IET Applied to Industrial Refractory Testing

Original Language: French

The Challenge

Quality control of refractory products traditionally relied on destructive testing, crushing samples to measure strength, cutting sections for microstructural analysis. The Minerals & Refractories Laboratories in Nancy needed something better: a method that was non-destructive, rapid, simple, and inexpensive.

The impulse excitation technique had already proven itself in the abrasives industry for grading grinding wheels. The question was whether the same physics would translate to the different geometries, compositions, and quality requirements of refractory products.

The Solution

The research team systematically evaluated the GrindoSonic instrument on various refractory shapes and compositions. The underlying principle transfers directly: a refractory’s resonant frequency depends on its elastic modulus, which in turn reflects the material’s density, porosity, and bonding integrity.

The study mapped out the instrument’s capabilities and limitations for refractories, determining which product types responded well to the technique and establishing the correlations needed to interpret readings as quality indicators.

Results

The investigation confirmed that impulse excitation provides excellent results for refractory testing. The method’s speed and simplicity made it practical for production-scale quality control, while its non-destructive nature allowed testing of actual production parts rather than sacrificial samples.

For the French refractory industry, this research opened a new approach to quality assurance, one that could screen 100% of production rather than relying on statistical sampling of destructively tested specimens.

Key takeaway: IET originally developed for grinding wheel grading transferred directly to refractory products, replacing destructive sampling with 100% production screening.