Kaplanmış Gözenekli Ti6Al4V İmplantların Lazer Metal Toz Ergitme (LAM) Teknolojisi ile Üretimi ve Karakterizasyonu

Abstract

Metal orthopedic implants are the pioneer medical devices for functionally providing internal repair at bone damage. The suitable mechanical properties for the applied area and biocompatibility features to prevent negative effects on the body are the minimum requirements the implants should have. The typical studies on the ideal implant material are carried out on titanium and its alloys due to their high mechanical strength and osteointegration properties. However, Ti6Al4V alloy implants made by conventional methods in the market are far from ideal implant properties due to disadvantages such as high mechanical strength, stress protection effect and low ductility. To solve this problem, porous implants with triple periodic minimal surface (TPMS) lattice structure was used in order to integrate the tissues into the implant better and approach the elastic modulus of bone. The beginning point of the thesis is the design of the controlled TPMS lattice structures to provide the desired mechanical properties and porosity ratio and cell movement, and the production of Ti6Al4V implants with this structure using laser metal powder melting (L-PBF) technology. The general aim of the thesis is to design and produce Ti6Al4V TPMS implants that can be used in orthopedic surgery, with mechanical properties closer to bone and higher activation in terms of biocompatibility compared to conventional non-porous titanium implants on the market. In addition, it is aimed to increase osteointegration by coating porous implants with calcium phosphate and polymer composite. According to the aim, the first part of the thesis was the design and production process for Ti6Al4V TPMS structures. This section also includes the iterative process with the optimization of TPMS design parameters first, then LAM process parameters and final step cleaning process parameters to reach cleaned fully dense and high dimensional accuracy as implant requirements. The second work package of the thesis is the coating process began with surface functionalization and continued with CaP / Polymer composite synthesis and dip coating process, finally, coating tensile tests were performed to determine the coating quality and mechanical properties between the composite and titanium surface. In the third chapter, the cytotoxicity test was applied to obtain the biocompatibility properties of Ti6Al4V porous implants.