Microstructure and mechanical properties of friction rolling additive manufactured crossover components

Existing solid-phase friction-based additive manufacturing technologies, including friction rolling additive manufacturing (FRAM), are predominantly limited to fabricating simple geometries. This paper represents the initial application of FRAM to fabricate AA6061 aluminium alloy crossover samples. The results reveal no oxygen aggregation in the crossover sections, demonstrating robust interlayer bonding without defects. The subsequent material fully mixed with the pre-existing deposited material under the extrusion force of the tool head, increasing the material entering the plasticising zone. The crossover section experienced greater plastic deformation, leading to enhanced recrystallization and a finer grain structure than the non-crossover section. The maximum tensile strength of the crossover and non-crossover section was 179.0 MPa and 189.0 MPa, respectively, reaching 85.2% and 90.0% of the base material.