Structural anomaly

The word anomaly derives from the Greek ἀνωμαλία, meaning unevenness or irregularity. A structural anomaly is a formation deviating from the typical structure or a structural defect (example in Fig. 1).

The atypical formation or irregularity can concern the

  • Type
  • Size
  • Shape
  • Quantitative distribution,
  • Epitaxy

of grains and phases.

Additional references:
Inoculant inclusions
Inverse chill
Segregation factor
hard inclusions
Hard spots
Iron needles
Cold drops 
Oxide inclusion
Gas porosity

  • Fig. 1: Structural anomaly in the form of  cold drops in the micrograph of a pressure die casting made of Al Si9Cu3(Fe)DF, the anomaly is characterized by the very fine dendritic structure and its clear delimitation from the surrounding matrix (structural matrix), source: Metallographic Atlas of Cast Aluminium Alloys