TY  - EJOU
AU  - Nomura, Naoyuki 
AU  - Dong, Mingqi 
AU  - Zhou, Zhenxing 
AU  - Zhou, Weiwei 

TI  - Advanced Powder Fabrication Techniques for Laser Powder Bed Fusion
T2  - The International Conference on Computational \& Experimental Engineering and Sciences

PY  - 2024
VL  - 31
IS  - 4
SN  - 1933-2815

AB  - Laser powder bed fusion (L-PBF) exhibits many technological opportunities for producing high-performance metallic parts with tailored architectures. However, fabrication of suitable composite powders possessing good flowability, controllable particle size and distribution is a currently prerequisite and main challenge. In this work, two novel techniques, namely freeze-dry pulsated orifice ejection method (FD-POEM) [1] and ultrafine bubble (UFB)-assisted heteroagglomeration [2], have been developed to fabricate uniform composite powders. By taking MoSiBTiC alloy powders as an example, the working principle of FD-POEM process was firstly illustrated. The spherical FD-POEM particles were consisted of typical mesh structures induced by the sublimation of ice crystals, benefiting to enhanced laser absorptivity. In addition, high-concentration, impurity-free nanoceramic/metal composite powders were fabricated using the negatively charged UFBs. Thanks to their bridging effect, individual ZrO<sub>2</sub> or Al<sub>2</sub>O<sub>3</sub> nanoparticles up to ~10wt% were homogeneously decorated on the surface of Ti-6Al-4V powders. The nanoceramics were completely decomposed and dissolved into the matrix during L-PBF; thus, a unique Ti nanocomposite exhibiting a high tensile strength of 1.4GPa and an acceptable ductility of 8.1% was fabricated. This work offers new insight into the fabrication of unique L-PBF powders and the mechanical functionalization of metallic parts.
KW  - Laser powder bed fusion (L-PBF); freeze-dry pulsated orifice ejection method (FD-POEM); ultrafine bubble (UFB); heteroagglomeration; composite powders

DO  - 10.32604/icces.2024.012381