Study on microstructure and mechanical properties for L-PBF iron matrix composites reinforced by epoxy resin

Laser powder bed fusion (L-PBF) technology has a wide range of applications in the forming of ceramic materials, polymer materials, and metal materials, especially in the fields of biomedical, aerospace, and automotive porous materials showing unique advantages. However, the microstructure and properties of iron matrix composite powders formed by L-PBF and reinforced by polymers have rarely been studied. In this paper, L-PBF was used to prepare the composite powder material of iron and epoxy resin (ER) as a binder. Firstly, according to the strength and precision of forming billet, the scanning speed, laser power, layer thickness, and scanning interval were optimized by orthogonal test. Secondly, the effects of the post-treatment method, and high-temperature sintering process on its mechanical properties were studied. Finally, the modified liquid ER was added to the post-treated iron matrix specimens, and the microstructure and mechanical properties of the samples before and after infiltration were analyzed using SEM, TGA, and tensile tests. The results show that the mechanical properties and elongation of the metal samples increased from 9.35 MPa to 5% to 19.64 MPa and 10%, respectively. Therefore, the microstructure and mechanical properties of L-PBF iron matrix composites can be reinforced through the infiltration of epoxy resin, to achieve low-cost, high-performance composite materials preparation, which provides a new research application of additive manufacturing technology in the field of metal matrix composites.