Thermophysical Measurements on Iron Above 1500 K Using a Transient (Subsecond) Technique

Area of Science:

• Materials Science
• Thermodynamics
• Physical Chemistry

Background:

• Accurate thermophysical property data for pure iron is crucial for high-temperature applications.
• Understanding phase transformations in iron requires precise measurements of its properties.
• Previous data may lack accuracy or resolution at extreme temperatures.

Purpose of the Study:

• To simultaneously measure heat capacity, electrical resistivity, and hemispherical total emittance of pure iron.
• To determine the melting point of iron using a transient technique.
• To investigate the influence of the solid-solid phase transformation (γ → δ) on these properties.

Main Methods:

• Utilized a sub-second duration, transient technique for simultaneous property measurements.
• Employed high-purity (99.9%) iron samples.
• Conducted measurements in the temperature range of 1500 to 1800 K.

Main Results:

• Observed increases in heat capacity and electrical resistivity attributed to the γ → δ phase transformation.
• Measured a hemispherical total emittance of 0.33 at 1720 K.
• Determined the melting point of iron to be 1808 K (average of two experiments).

Conclusions:

• The γ → δ phase transformation in iron significantly impacts its thermophysical properties.
• The transient technique provides accurate, simultaneous measurements of key properties.
• The determined melting point and property data enhance the understanding of iron's behavior at high temperatures.