Metallography

Generally speaking, the transformation of alloys by wrought and heat treatments requires knowledge of their structural states and the kinetics of their evolution. These treatments rely on two types of data, the most common measurement methods of which are the subject of this presentation:

• analysis of physico-chemical transformation points: thermal, dilatometric and magnetic analysis;

• analysis of structures (or constituent topography: quantity, shape, phase dispersion) by optical or electron microscopy.

Structural analysis is topographic, but micrography is not the only way to map the shape of structural components. Any point-systematic analytical exploration of a physical or mechanical property can map the properties of the structure's constituents. A common example is analysis by scanning microprobe or scanning electron microscope; in all cases there will be modulation, by a particular property, of the signal reflected or transmitted by the metal.