Production and characterization of Mg-4% Zn infiltrated titanium alloy for bio medical applications

Abstract

Titanium alloys play a major role in making bio-implants such as bone replacements etc. However, their elastic modulus is very high compared with human bone and also their biocompatibility is not so good. The difference in the young’s modulus leads to stress shielding. Magnesium alloys have good biocompatibility in terms of bone growth, but they are poor in stiffness. Hence, bone replacements containing a combination of titanium infiltrated with magnesium is better from the view point of both stiffness and biocompatibility. In this work, a titanium alloy substrate with square mesh, produced through additive manufacturing, is infiltrated with magnesium-4% zinc alloy. The infiltration of magnesium into the meshes of titanium alloy will reduce the weight and Young’s modulus of the bio implant produced from this alloys combination. The magnesium alloy present in the titanium meshes may dissolve into the blood and may not increase the bone growth when it is very soft. Hence, age hardening heat treatment is to be given to the magnesium alloy to increase its strength. By doing so, the strength of Mg-4%Zn alloy increased and hence the magnesium alloy could able to support the bone growth rather than dissolving in blood. The addition of zinc to the magnesium increases the age hardening ability of magnesium alloys and hence strength of the same. In this work, the magnesium alloy infiltrated titanium mesh structured bio implants were produced and age hardened. Then these implants were characterized for their microstructure and hardness.Titanium alloys play a major role in making bio-implants such as bone replacements etc. However, their elastic modulus is very high compared with human bone and also their biocompatibility is not so good. The difference in the young’s modulus leads to stress shielding. Magnesium alloys have good biocompatibility in terms of bone growth, but they are poor in stiffness. Hence, bone replacements containing a combination of titanium infiltrated with magnesium is better from the view point of both stiffness and biocompatibility. In this work, a titanium alloy substrate with square mesh, produced through additive manufacturing, is infiltrated with magnesium-4% zinc alloy. The infiltration of magnesium into the meshes of titanium alloy will reduce the weight and Young’s modulus of the bio implant produced from this alloys combination. The magnesium alloy present in the titanium meshes may dissolve into the blood and may not increase the bone growth when it is very soft. Hence, age hardening heat treatment is to ...