What is the importance of thermal analysis



The Thermal analysis is an investigation method for measuring the physical and chemical properties of elements and compounds.

Classification

In the dynamic Thermal analysis, the substance to be examined is slowly heated or cooled, i.e. in thermodynamic equilibrium. At the same time, a thermocouple continuously determines the temperature.

Dynamic thermal analysis methods are thermogravimetry, dynamic differential calorimetry, differential thermal analysis and emission gas thermal analysis.

The static Thermal analysis is used, among other things, in mineralogy. The mineral sample to be examined is brought to a constant temperature for hours or days. During this time, the loss of water or ignition is recorded and recorded.

In this way, transition points from solid to liquid to gaseous (melting and (boiling point) with temperature changes can be determined (see also: physical state).

Significance for materials science

Of particular interest in metals, alloys and plastics are the transitions from solid to liquid as well as possible temperature changes in the solid state, since transformations of the crystal system also become noticeable through breakpoints. Crystal system conversions can be used to harden metals and alloys.

The measurement results are entered in temperature-time diagrams. The points connected to one another result in the heating and cooling curves.

The cooling curves shown here are, for example, characteristic of amorphous substances (1), a pure element or a eutectic alloy (eutectic point) (2), an alloy with solid solution formation (3) and a near-eutectic alloy (4)
Curves 2, 3 and 4 see also alloy

literature

Practice of thermal analysis of plastics - Ehrenstein / Riedel / Trawiel (ISBN 3-446-22340-1 - Carl Hanser Verlag Munich)

Methods of thermal analysis - W.F. Hemminger / H.K. Cammenga (ISBN 3-540-15049-8 Springer Verlag Berlin)

Categories: Materials Science | Material testing