Design of Porous Ti-6Al-4V Alloy Structures for Bioimplants

This paper presents the efforts made in studying the elastic modulus of porous Ti-6Al-4V alloy structures for biomedical load-bearing applications. The major issues concerning with the metallic implants is the mismatch of elastic modulus between the cortical bone and the metallic implant which resulted in stress shielding and cause to disassociation of the implant with the surrounding bone. In addition to this, fixation of the implant to the bone is crucial in the implant functioning. In present work, the elastic modulus of porousTi-6Al-4V alloy structure with different porosity ranging from 10 vol.% to 50 vol.% were estimated using the Nielsen's relationship. From the results, it is found that the porousTi-6Al-4V alloy structure with the porosity of 50 vol. % possesses the elastic modulus about 24.19GPa which is close to the human cortical bone. Fabrication of porous implant structures with the designed porosity is difficult with the conventional manufacturing techniques. The additive manufacturing technology capable of produce the porous implants with the designed porosity. We have demonstrated the proof of tailoring the elastic modulus of metallic implants with the designed porosity and minimise the mismatch of elastic modulus between theTi-6Al-4V alloy structure and the human cortical bone.