Research on the Microstructure and Pore Characteristics of Fused Filament-Fabricated Porous Tungsten

Abstract:

Porous tungsten structures were prepared by fused filament fabrication (FFF). The microstructural evolution at each stage of the FFF process and the final pore characteristics of the sintered tungsten were investigated systematically. The results show that porous tungsten components with tightly bonded layers and no defects are successfully prepared by FFF. The maximum loading of commercial tungsten powder with a particle size of 3 μm reaches 56%, and the compounded feedstock exhibits excellent rheological properties. Furthermore, the influence of printing parameters on the green density was investigated, identifying the optimal combination: the nozzle diameter of 0.6 mm, a layer thickness of 0.1 mm, and the printing speed of 30 mm/s. The porous tungsten prepared by FFF shows a uniform pore distribution. As the sintering temperature increases, the average pore size decreases, the complexity of the pores increases, and the hardness and compressive strength increase.