A method to quantify crystallinity in amorphous metal alloys: A differential scanning calorimetry study

Area of Science:

• Materials Science
• Thermodynamics
• Analytical Chemistry

Background:

• Amorphous metal alloys are technologically important but their devitrification behavior requires precise characterization.
• Existing methods for determining crystallinity can be complex, expensive, or require specialized equipment.

Purpose of the Study:

• To develop a novel differential scanning calorimetry (DSC) method for quantifying the crystallinity of amorphous metal alloys.
• To establish a reliable and accessible technique for analyzing devitrification processes.

Main Methods:

• Utilized differential scanning calorimetry (DSC) to measure thermodynamic enthalpies of amorphous, crystalline, and partially devitrified samples.
• Developed a calculation method based on enthalpy data to determine initial crystallinity, changes in crystallinity, and percentage crystallinity as a function of temperature.

Main Results:

• The DSC method accurately calculates initial and percentage crystallinity, even at low levels (a few percent).
• A linear correlation was observed between pre-determined and calculated crystallinities, negating the need for calibration samples.
• The technique avoids the requirement for expensive in situ accessories like those used in electron microscopy.

Conclusions:

• The developed DSC methodology provides a primary, cost-effective technique for characterizing the devitrification behavior of amorphous materials.
• This method offers high sensitivity and accuracy for determining crystallinity percentages in amorphous alloys.