Source: J. Jacob Chavez, Ryan T. Davis, and Taylor D. Sparks, Department of Materials Science and Engineering, The University of Utah, Salt Lake City, UT

Thermal expansion is extremely important when considering which materials will be used in systems that experience fluctuations in temperature. A high or low thermal expansion in a material may or may not be desirable, depending on the application. For instance, in a common liquid thermometer, a material with a high thermal expansion would be desirable due to its sensitivity to temperature changes. On the other hand, a component in a system that experiences high temperatures, such as a space shuttle re-entering the atmosphere, will need a material that will not expand and contract with large temperature fluctuations in order to prevent thermal stresses and fracture.

Dilatometry is a technique used to measure the dimensions of area, shape, length or volume changes of a material as a function of temperature. A principal use for a dilatometer is the calculation of thermal expansion of a substance. The dimensions of most materials increase when they are heated at a constant pressure. The thermal expansion is obtained by recording the contraction or expansion in response to changes in temperature.

1. Machine Start Up and Set Up. Begin with powering the computer, equilibrating the sample temperature ensuring it is at room temperature (about 20°C), and dilatometer on. Make sure cooling system is running and nitrogen gas is flowing along with all other necessary systems. The nitrogen gas will need to be turned on between when the furnace is turned on and when the sample is inserted for testing. The pressure for the gas will be specific to the dilatometer, for ours it is 10 psi.
2. Determine which experiment will be conduc

The results of dilatometers generally include data of temperatures, expansion lengths, and time. Different softwares used together with dilatometers can return results in different ways. Some softwares only return data points, while others have plotting functions and other analysis features. The software used in the procedure above used WorkHorseTM. This program returns data in a .txt file that can then be plotted using a software such as- Matlab, Qtgrace or Excel. Fi

Dilatometry is a technique for measuring the dimensional thermal expansion of a material. Frequently this value is found by measuring the change in length as a material is heated and cooled. Thermal expansion is quantified by change in length divided by initial length. In addition to thermal expansion, the technique offers insights into vacancy formation, phase changes, and dislocation evolution in response to heat treatments.