AlFeCoNi high entropy alloy fabricated by powder-bed arc additive manufacturing

Abstract

Additive manufacturing has received a lot of attention in recent years. Compared with traditional manufacturing technology, additive manufacturing has many irreplaceable advantages. In 3D printing technology, most technologies need to prepare materials in advance when printing high-entropy alloy materials, which greatly increases the cost and time of 3D printing. Therefore, powder-bed arc additive manufacturing (PAAM) technology is adopted. However, PAAM technology will cause the grain size of the material to be very large, leading to poor mechanical performance. Therefore, I utilize the eutectic reaction to reduce the grain size of the material to obtain excellent mechanical properties. Therefore, this project uses PAAM technology to prepare high-entropy alloys with excellent properties, and observes the microstructure of the materials to analyze the reasons for the excellent mechanical properties of the materials. Therefore, this project will conduct a comprehensive study of the material's microstructure using advanced scanning electron microscopy (SEM). These advanced methods can observe the microstructure of materials during 3D printing.

In our project, the ductility of materials produced through PAAM technology increased by 8.5% compared to materials produced using traditional casting technology. Since 3D printing is a directional solidification method, the unique dendritic microstructure of directional solidification appears, which improves the ductility of the material. Due to certain technical problems in PAAM technology, there will be Al elements in the printing process. The loss results in the material not exhibiting a perfect lamellar-like microstructure at the top. At the same time, the content of the soft 〖L1〗_2 phase at the top of the sample is approximately 72.3%. This phenomenon also leads to a decrease in the strength of the material, which is 90MPa lower than that of materials produced by traditional casting technology.