Advances in medical technology come with a large amount of materials that are currently under consideration for possible implantation into the human body. With the object to be compatible with the body these potential materials need do not cause any further harm. Biodegradable materials are dispelling the current stereotype in biomaterial science to research and produce only corrosion resistant materials. Especially, materials which consist of nutrients existing in the human body are high-potential expectants for this approach. The main point is that biodegradable implants and coatings can support tissue regeneration and healing in the process of material degradation and can gradually dissolve with replacement by natural tissue.
Biodegradable metals take priority over current biodegradable materials for example bioactive glasses, polymers or ceramics as applied to loads in body that require a higher tensile strength and a Young’s modulus that is closer to bone.
The magnesium has drawn great consideration in capacity of biodegradable material for bone joint replacement due to its similar mechanical properties with human bone, biodegradation and biocompatibility. By the way, the high degradation rate of magnesium delimitates its application as bioimplant materials. In the past decade, various approaches have been investigated to improve the degradation behaviour of magnesium. Development of biocompatible coatings and alloying are the most common methods that have been investigated. It has to be said, biocompatible calcium phosphate (CaP) has limelighted great attention in recent years as a coating material on magnesium and its alloys.
The development of biocompatible CaP coating on the surface of magnesium alloys is one of the way to control their degradation rate. Thick CaP coatings that were prepared by wet-chemical methods are well known. Nevertheless, wet-chemical methods of CaP coating deposition on the surface of magnesium alloys often is afflicted with weak adhesive strength. Currently, researchers are prone to establish a thin protective surface layers on the surface of alloys, which allows to keep the initial substrate topography and enhance the corrosion resistance. However, even by now, there is insufficient information on the corrosion resistance of these coatings. The RF magnetron sputtering is a preeminent method for deposition of pure HA. On top of everything else, a HA coating received by RF magnetron sputtering is well-adhered to the substrate.