Sintering of aluminum and aluminum alloys by powder metallurgy: A critical review of techniques, densification mechanisms, microstructural evolution, and mechanical property development

Aluminum powder consolidation depends on effective interparticle bonding and pore removal. This review examines conventional and microwave sintering, hot pressing, spark plasma/field-assisted sintering, hot isostatic pressing, selective laser sintering, laser powder bed fusion, and flash/current-assisted processing. It focuses mainly on literature from 1990 to August 2026, emphasizing developments from 2022 to 2026, and analyzing powder–process–microstructure–property relationships. Comparisons consider alloy composition, powder features, oxide states, reinforcement levels, thermal history, and testing methods. Achieving near-full density does not always imply superior mechanical properties, as retained oxygen, weak interfaces, or altered strengthening phases may persist. Faster consolidation limits thermal exposure, while pressure and heat treatments can affect strength-ductility trade-offs. Fatigue, fracture, and wear data are evaluated based on consistent testing and material conditions. Process choice depends on component needs, geometry, production scale, and qualification demands. Lack of consistent datasets and incomplete reporting on energy, cost, and uncertainty hinder broad process ranking. Future work should prioritize standardized testing, component-level validation, and externally verified models for dependable processing and sustainable manufacturing.