Enhancement effect of Al₂O₃@Y₃Al₅O₁₂ short nanofibers on aluminum alloy matrix composites

By using a kind of composite nanofibers with core-shell structure to reinforce aluminum alloy matrix composites, it can improve the tensile strength while increasing plasticity. Al₂O₃@Y₃Al₅O₁₂ short nanofibers reinforced 2024 aluminum alloy composites were prepared by vacuum hot-pressing sintering technique. The effects of Al₂O₃@Y₃Al₅O₁₂ nanofibers content on the relative density, hardness, tensile strength and elongation of composites were studied, and the effect of the core-shell structure on the toughening mechanism of the composites explored. The results show that the Al₂O₃@Y₃Al₅O₁₂ short nanofibers have good dispersion, and the fibers are uniformly adsorbed on the surface of aluminum alloy particles without stratification and agglomeration was method of ultrasonic dispersion and mechanical agitation. After hot-pressing sintering, the Al₂O₃@Y₃Al₅O₁₂ short nanofibers are uniformly dispersed in the aluminum alloy matrix with a form of short fibers, and a small content of Al₂O₃@Y₃Al₅O₁₂ short nanofibers plays the role of bridging and hole filling, which increases the relative density and hardness of the composites. There are the maximum tensile strength and elongation of the composites at the nanofiber mass fraction of 1wt%, which increase from 249.3 MPa (matrix) to 299.1 MPa, 2.9% (matrix) to 4.3%, respectively. The addition of Y₃Al₅O₁₂-Al₂O₃ short nanofibers can refine the composites grain, hinder crack propagation, and the plastic deformation of Y₃Al₅O₁₂-Al₂O₃ core-shell structure plays a strengthening and toughening effect in the process of pulling out/breaking.