A novel processing route for the fabrication of porous magnesium biomaterials
Degree GrantorUniversity of Canterbury
Degree NameMaster of Engineering
Metallic biomaterials continue to play an essential role to assist with the repair or replacement of natural bone that has become diseased or damaged. Metals have high mechanical strength making them better suited to load-bearing applications than polymeric and ceramic biomaterials . At present, stainless steel, Co-Cr alloys and Ti alloys are three main metallic biomaterials used as bone prosthesis [2, 3]. Although these metals are, in monolithic form, biocompatible, fine debris particles and/or ions released over the lifetime of the implantation, coming into contact with the surrounding tissue appear to be not biocompatible. The abnormally high levels of metal ions and/or particles are believed to be associated with carcinogenic, toxic, inflammatory and allergic reactions eventually leading to the prosthesis aseptic loosening [4-10]. High mechanical stiffness of the three metals is also believed to associate with bone resorption – a situation where bone around the implant becomes thinner or more porous. The high stiffness metal, once implanted, changes the distribution of applied load in the adjacent bone [11, 12]. Recently, there have been interests in using magnesium and its alloy as a metallic biomaterial. Magnesium is a bioresorbable metal with an ability to enhance bone healing process [13, 14]. It also has lower stiffness making it more resemble to that of natural bone in terms of mechanical properties. This work presented in this thesis involves an investigation a manufacturing route that is feasible and viable for producing Mg foam for tissue engineering and bone implant applications. The microstructure and mechanical properties of Mg foam is studied and tested then compared with natural human bone.