3d printing of a continuous carbon fiber reinforced bronze-matrix composite using material extrusion

The main objective of this study is to investigate, for the first time, the feasibility of 3d printing a continuous carbon fiber (CCF) reinforced metal matrix composite using a cost-effective material extrusion (MEX) technology. Notably, this paper presents a detailed analysis of the microstructure and mechanical and physical properties of a bronze matrix composite reinforced with CCF. The results reveal that CCF significantly impedes the expected densification levels of the composite's structure, causing extensive gaps between the bronze particles. However, despite the high porosity level, the composite's electrical conductivity remains relatively high, demonstrating the limited negative impact of the CCF material on the composite's conductivity. Moreover, mechanical evaluations were performed through 3-point bending and tensile tests, highlighting the composite material's advantages and limitations. The results show that the composite material exhibits an improved yield stress of 76 %, increased ultimate tensile strength of 20 %, and an extended fracture strain of 30 %. However, the flexural strength decreases by 23% due to the presence of massive gaps formed by CCF.