dilatometriei

Dilatometry is a thermal analysis technique used to measure the change in dimension of a material as a function of temperature. The primary measurement is the expansion or contraction of a sample when it is heated or cooled. This change in dimension is typically measured by a probe that makes contact with the sample, and the displacement of the probe is recorded. The instrument used for this measurement is called a dilatometer.

Dilatometry is employed to study various material properties and phenomena. One of the most common applications is the determination of the coefficient of thermal expansion (CTE), which quantifies how much a material changes in size for a given change in temperature. This is crucial for material selection in applications where temperature fluctuations are significant, such as in aerospace, automotive, and construction industries. By understanding the CTE, engineers can prevent stresses and failures caused by differential expansion between joined materials.

Furthermore, dilatometry can reveal phase transitions within a material. As a material undergoes a phase change, such as melting, solid-state transformations, or glass transitions, there are often associated volume changes. These volume changes manifest as changes in the slope of the dilatometer's displacement-temperature curve, allowing for the identification and characterization of these transitions. This makes dilatometry valuable in metallurgy, ceramics, and polymer science for understanding material behavior during processing and in service. The technique requires careful sample preparation and calibration of the instrument to ensure accurate and reproducible results.