Microstructure evolution and mechanical properties of Ti-6Al-4V alloy prepared by fused filament fabrication

The Ti-6Al-4V alloy may significantly reduce production costs by Fused filament fabrication (FFF) technology. However, this technique may give rise to metallurgical defects, such as pores, which can notably reduce the mechanical properties of Ti-6Al-4V alloy. Hence, the study probed into the influence of different process parameters on the microstructure and mechanical properties of Ti-6Al-4V alloy.Firstly, the optimum parameters were obtained, including printing speed of 40 mm/s, the raster width of 0.5 mm, layer thickness of 0.1 mm, and extrusion temperature of 190 °C. Furthermore, the as-fabricated parts exhibited maximum tensile and compressive strengths of 896.87 MPa and 1494.16 MPa. After sintering, the microstructure of Ti-6Al-4V displayed a distinct basketweave pattern composed of an interconnected network of β-phase, lamellar α-phase and pores. Finally, this paper discussed the effect of process parameters on pores. The layer thickness had the most notable impact on the pores, with raster width coming in second. Reducing layer thickness reduced pores by improving the connection between layers. The raster width has a significant effect on part density, as it influences the dimensions of inter-filament pores.A wider rating width results in an increase in inter-filament pores.The results of this study can be used to develop a strategic method for optimizing the printing process of various materials for reducing pores and improving material properties.