Plastic strain accommodation and acoustic emission during melting of embedded particles

Melting point phenomena of micron-sized indium particles embedded in an aluminum matrix were studied by means of acoustic emission and differential scanning calorimetry. The acoustic response measured during melting increased with indium content. Correlations with differential scanning calorimetry suggest that large indium particles or particles at grain boundaries generate the greatest acoustic emission. Acoustic emission during melting suggests a dislocation generation mechanism to accommodate the 2.5% volume strain required for melting of the embedded particles.

► Micron sized indium particles were embedded in an aluminum matrix.
► Acoustic emission was measured during melting of the indium particles.
► Results support dislocation strain accommodation posed by internal friction studies.
► We suggest a new source of solid state phase transformations dislocation generation.