Potential assessment in laser powder bed fusion of bionic porous Ti scaffolds concerning compressive behavior, porosity, and surface roughness

Abstract

The fabrication of cellular structures with biocompatible materials for implants has increased in recent years because of human aging and traffic road accidents. Laser powder bed fusion or Selective laser melting (SLM) can fabricate various load-bearing implants with mass customization in design and manufacturing. This work involves a manufacturability study in selective laser melting of biomedical Ti alloy implant plug for Osteoarthritis patients. The investigation involved the control variables like laser power (175,185,195) watt, scanning speed (1100,1250,1400) mm/s, and hatch spacing (0.065,0.0725,0.08) mm alongwith output responses such as Compressive yield strength, Elastic modulus, porosity, and surface roughness. The experiments were performed using Box Behnken design in Response surface modelling for collaborative optimization. The results were explicitly explained with an in-depth process physics supported with Characterization involving Scanning electron microscopy, Electro-dispersive spectroscopy, X-ray diffraction, micro-computed tomography, optical profilometry analyses, and process schematics. The optimal setting with laser power (195 W), scanning speed (1100 mm/s), and hatch spacing (0.068 mm) yielded high compressive yield strength (22.41 MPa), near trabecular bone Elastic modulus (0.891GPa), controlled porosity formation (29.32 %), and optimal surface roughness (3.647 μm). Topography resulted in a prominent lack of fusion pores because of low energy density levels, whereas the optimal settings produced around 15 % improvement from design of experiments data.