Influence of boron content on the microstructure of sintered Al_62.5−xCu_25.3Fe_12.2B_x alloys (x = 0, 3, 5)

Microstructures and morphological features of a series of sintered quasicrystalline Al_62.5−xCu_25.3Fe_12.2B_x alloys, with x ranging from 0 to 5 at.% were studied using x-ray diffraction, scanning electron microscopy, x-ray mapping, and electron probe microanalysis. Electron backscattering diffraction (EBSD) was also used to get information about the structures of some phases and identify the crystalline relationship in-between phases. Increasing x results in the change of the nature of extra phases. These secondary phases are all less than 1% in volume of the total matter except for the β phase at 5% of boron. Whatever the percentage of boron considered, boron seems to concentrate essentially in the parasite phases confirming doubts found in literature about the solubility of boron inside the face-centered-icosahedral Al–Cu–Fe phase. No special crystallographic relationship in between the tested phases could be spotted. EBSD is thus also confirmed as an excellent technique to get quasicrystalline grains orientations.