Vat photopolymerization additive manufacturing of B₄C/Al composites

B₄C/Al composite components show significant potential for applications in fields such as mechanical engineering, aerospace, and nuclear industry. Vat photopolymerization (VPP) additive manufacturing is a potential method to fabricate B₄C/Al composites with complex structures, owing to its advantages such as minimal thermal stress, high precision, and excellent surface finish. However, challenges such as the poor settling stability of the composite slurry and insufficient curing capability have hindered the VPP process of B₄C/Al composites. In this study, we introduced a modified polyurea solution to enhance the shear-thinning properties of the B₄C/Al composite slurry, improving its settling stability during static periods without affecting the subsequent 3D printing process. Additionally, large-sized AlSi10Mg and B₄C particles were selected to ensure the slurry's curing ability met the requirements of the VPP process. By setting the slice thickness to 25 μm, adjusting the light intensity to 18–22 mW/cm², and setting the exposure time to 6–8 s, high-precision printing of complex B₄C/Al structures was achieved, with a dimensional deviation rate of less than 5 %. After debinding and sintering, B₄C/Al composite samples were obtained. As the relative content of AlSi10Mg increased, the flexural strength and bulk density of the composite samples also increased, while the open porosity decreased. Finally, the 20B80Al sample exhibited a bulk density of 2.38 g/cm³, an open porosity of 8.63 %, a flexural strength of 152.83 MPa, a fracture toughness of 6.38 MPa·m^1/2, and a Vickers hardness of 93.43 HV. This study provides a promising approach for fabricating B₄C/Al composite with complex structures using the VPP additive manufacturing.