Fabrication of Ti-6Al-4V Porous Scaffolds Using Selective Laser Melting (SLM) and Mechanical Compression Test for Biomedical Applications

Bone implants are extensively used in biomedical science for replacement of bone and joint defects, but a variation of stiffness between implant material and bone causes load redistribution around the implant, resulting in autogenous bone fracture or loosening of implant, called stress shielding. To overcome this problem, porous biocompatible titanium alloy (Ti-6Al-4V) is used to reduce the stiffness of metallic implants equivalent to bone stiffness. Ti-6Al-4V is considered to fabricate porous implant scaffold due to its excellent mechanical properties, biocompatible nature, higher corrosion resistance, and high strength-to-weight ratio. Four different porous scaffolds, namely diamond, grid, cross, and vinties, are modeled using Rhino 6 software, where 65% theoretical porosity is maintained. Additive manufacturing (AM) technique, mainly selective laser melting (SLM), is used to fabricate these porous scaffolds. Actual porosity and surface roughness of the fabricated samples are measured. Compression tests of each porous scaffold are performed in INSTRON compressive testing machine. Elastic modulus of fabricated samples shows excellent matching with a human bone, while compressive strength shows superior value compared to the human bone which will help to reduce the stress shielding effect and also will increase the longevity of the implants. The relative elastic modulus (modulus ratio of porous scaffold to solid cube) of the samples is studied using the Gibson–Ashby correlation model. The porous scaffolds made with Ti-6Al-4V have low effective Young’s modulus, excellent compressive strength, and sufficient cell accommodation space to fulfill medical requirements for clinical demands.