Density Determination

The program Density Determination serves in the determination of the temperature-dependent density of solid samples beyond the melting temperature. The calculations are based on dilatometer measurements carried out in a container stable against temperature (sapphire, graphite, quartz glass, etc.). During melting, the sample completely fills the container. Therefore, with correct sample preparation, there is a monotonic transition of the dL/L0 curve into the liquidus range.

This software is of interest for all researchers who require a more accurate determination of phase transitions. The data should also be of interest to designers who work in the area of casting technology. It is absolutely critical for analyses in which the density is required beyond the melting point (e.g. determination of the thermal diffusivity by means of laser flash analysis).

However, if the sample diameter is smaller than the inside diameter of the container, the slope of the dL/L0 curve decreases with the start of melting. If the sample diameter is considerably smaller, a drop in the curve can even be seen. For technical reasons, it is often impossible or too costly to prepare perfect samples. In order to obtain correct results for such samples as well, the almost linear segment of the liquidus curve (red), indicated by the two markers ( < ) is approximated by a polynomial and this area is extended to the vertical cursor, which characterizes the start of the melting process.

The approximated curve, together with the red part of the liquidus curve that follows, is shifted such that it begins at the point of intersection of the vertical cursor with the solidus curve (pink). Thus, errors which result from the limited precision of the sample preparation are corrected to a great extent.

Density and volume change of Inconel 718 from room temperature up to 1450 °CDensity and volume change of Inconel 718 from room temperature up to 1450 °C