Comparison of Additively Manufactured and Cast Aluminum A205 Alloy

The relationships between the microstructureMicrostructure and thermal behaviour of additively manufactured and cast aluminumAluminum A205, a recently developed Al–Cu–Mg–Ag–TiB2 alloy, were investigated. Microstructural characterizationMicrostructural characterization performed using scanning electron microscopy (SEMScanning electron microscopy (SEM)) indicated a significant difference in grain size between laserLaser powder bed fusion (LPBF) and cast specimens. Ultrafine round intercellular precipitates were observed in the LPBF structure, while intergranular precipitates were found in the cast structure. Trans-cellular TiB2 particles were observed in the LPBF structure, while accumulated intergranular TiB2 particles were found in the cast structure. Moreover, X-ray diffraction analysis revealed a higher fraction of precipitates in the LPBF specimen compared to the cast specimen. This was attributed to extremely high cooling rates which extend the solubilitySolubility of alloying elements in the matrix. The thermo-analytical study demonstrated a strong correlation between the microstructural scale and precipitate dissolutionPrecipitate dissolution kinetics of A205. The higher diffusion rate inherent in refined microstructuresMicrostructure facilitates the dissolutionDissolution of precipitates in the LPBF A205.