Quantitative metallography

Generally speaking, the transformation of metal alloys by wrought, thermal and thermochemical treatments determines their properties of use. Knowing and quantifying microstructures before and after thermal, thermochemical or thermomechanical treatments is essential for controlling their effects and managing the process.

These processes are based on two types of data, the most common measurement methods of which are :

• analysis of physico-chemical transformation points (thermal, dilatometric and magnetic analysis), which is the subject of article [M 90] ;

• analysis of microstructures (or constituent topography: quantity, shape, phase dispersion) by optical or electron microscopy and associated techniques, which is the subject of the article [M 91] .

This article describes the possibilities of surface and volume quantification of microstructures, specific problems and standardized solutions. The application of these techniques provides the metallographic knowledge needed to optimize the choice of materials and their processing, which is crucial for maximizing the efficiency of the product-process-material triptych, and ultimately the suitability of the product, from both a technical-economic and environmental point of view.