Abstract A color-etching methodology was applied to an AA1100–25 vol.% B 4 C composite to enhance phase identification under optical microscopy. A solution of 50% (v/v) phosphoric acid in deionized water was used at − 5 °C under a constant current density of 0.02 A cm −2 . As a result, the aluminum matrix appeared pink, the B 4 C particles dark brown, TiB 2 interfacial layers formed distinct contours around the B 4 C reinforcement, and the Si-rich inclusions exhibited a bright blue hue. These contrasts made the interfaces between the B 4 C particles and the aluminum matrix clearly distinguishable. Complementary SEM and EDS analyses confirmed the presence of TiB 2 at the Al/B 4 C interfaces and Si-rich phases within the matrix. The proposed methodology provides a rapid and reliable means of identifying secondary phases and interfacial layers in Al–B 4 C composites.
Araujo et al. (Thu,) studied this question.