Microstructural and mechanical properties of Al-Cu-Mn-Ti graded porous aluminum alloy with tracheid micron-sized pores

As an effective strategy to enhance the compressive strength and energy absorption performance of porous materials, gradient design has been proposed as a viable solution for electric vehicle protection. Al-Cu-Mn-Ti graded porous aluminum alloy (GPAA) with tracheid micron-sized pores was fabricated by introducing wood fiber as space-retaining agents through powder metallurgy method . Gradient stratification of porous aluminum alloy (PAA) was achieved by adjusting the wood fiber content to control the porosity and pore size. The microstructure of GPAA and PAA in different proportions was characterized by X-ray CT and SEM/EDS to analyze the differences between gradient pore structure and uniform pore structure. Characterization of the samples showed that a distinct layered pore structure could be formed by regulating the wood fiber content, and the material successfully possessed tracheid micron-sized pores. Compression tests showed that the construction of hierarchical pores improves the compressive strength and energy absorption performance of the material. The maximum compressive strength before failure of the two groups of GPAAs reached 30.36 MPa and 53.81 MPa respectively, which increased by 263.2 % and 151.3 % compared with the compressive strength of typical PAAs. ● Graded porous aluminum alloys with tracheid micropores were prepared using wood fibers as space retainers. ● The content of wood fibers in each layer is used to control the foaming effect of TiH 2 to achieve the graded pore structure. ● The experiment shows that graded pore structures have higher compressive strength and energy absorption capability. ● The tracheid micropores of graded porous aluminum alloys have a higher support effect during heating and compression.