Investigations on the Solid-State Additive Manufacturing of Al Alloy: Process, Microstructure, and Crystallographic Texture

Additive ManufacturingAdditive manufacturing (AM) is crucial for Industry 4.0Industry 4.0 where automation and real-time decision-making are to be performed with minimal human intervention. Most AM techniques involve meltingMelting metal powders layer-by-layer to build components which allows for complex geometries to be achieved; however, some challenges that inhibit it from becoming mainstream are hot cracking, porosity produced in the specimens, anisotropy and heterogeneity in the components with respect to the microstructureMicrostructure, mechanical propertiesMechanical properties, and crystallographic textureTexture. Such problems could be overcome if AM is performed without meltingMelting. In this regard, additive friction stir deposition (AFSD) exhibits the highest potential for industrialization. AFSD involves depositing a solid metal feedstock bar layer-by-layer while being heated by a rotating tool. In this work, the process, microstructureMicrostructure, crystallographic textureTexture, and hardnessHardness of Al 60826082 alloyAlloys after AFSD have been investigated. A fine-grained microstructureMicrostructure was obtained. However, there was a reduction in the hardnessHardness by 54%. This could be due to the precipitatePrecipitates coarsening and dissolutionDissolution during the processingProcessing.