Keqiu Zhou, Xupeng Lian, Peng Zhang, Rong Bai, Jijun Ma, Jiasheng Zou
The increasing utilization of nuclear energy demands advanced materials that combine mechanical integrity with neutron shielding efficiency during spent fuel storage and transportation. This study proposes a dual optimization strategy: employing Monte Carlo N-Particle to determine optimal dopant particle size and composite ratio, while using Ansys Fluent to optimize selective laser melting process parameters for the preparation of Gd 2 O 3 /316L neutron-absorbing composites. The results show that with a thickness of 2.1 mm and when the Gd 2 O 3 particle size is reduced to 10 μm, the Gd 2 O 3 /316L composite material can achieve neutron shielding exceeding 90 % both in the thermal neutron spectrum and the spent fuel neutron energy spectrum. Considering Marangoni convection, thermal buoyancy, and gravity effects, the optimal Selective Laser Melting parameters are determined as 150 W laser power with 600-1200 mm/s scanning speed. Microstructural analysis reveals excellent interfacial bonding where Gd 2 O 3 integrates with the steel matrix, forming a 0.7 μm-thick interfacial layer that enhances particle-matrix cohesion. Fine, high-density dislocations distribute around nano-sized gadolinium oxide particles, thereby strengthening the composite. At a volumetric energy density of 105 J/mm 3 , combined with the effective partial load-bearing capability of the well-dispersed Gd 2 O 3 particles, the composite achieved a tensile strength of 580 MPa.