Abstract Scope |
High-strength aluminum matrix composite (AMC) reinforced with Al2O3 nanofibers was additively manufactured by laser powder bed fusion. We aim to establish a process window to produce high-density, defect-free AMC made of aluminum powder premixed with an in-lab synthesized Al2O3 nanofibers. Role of process parameters such as laser power, scan speed, hatch space, and scan strategy as well as fraction of reinforcement are investigated on densification, defects such as porosity and cracking, metal/oxide interface and possible segregation. We show at an optimum ratio of Al matrix to Al2O3 nanofibers and process parameters, the nano-additives result in a pinning effect in the developed AMC that enhance the strength, hardness, and wear resistance. We demonstrate that the improved performance is related to a high density of well-dispersed nanofibers, strong interfacial bonding between Al matrix and nanofibers, and ultrafine grain structure of the LPBF processed AMC. |