Preparation Of Biodegradable Iron-zinc Alloys By Electroforming And Their Properties Investigation

In recent years, the coronary heart disease has become a kind of threat to humans’health. The interventional therapy has been widely used because of its rapid treatment and good curative effect. The stent has a close relation with interventional therapy, which can be implanted to the pathological blood vessel and support the vessels. At present the stent implanted will stay in the body which will induce some adverse reactions such as inflammation unless taken out by a second surgery. However, it will do harm to people’s health. In this way, biodegradable stent is needed which will disappear after curing the sicken vessel. Large amount of studying shows that pure iron stent has super biocompatibility and mechanical property which is regarded as a suitable biomaterial for biodegradable implanting. But its degradation rate is too slow to satisfy the requirement of the biodegradable stent. In future research people pay more attention on increasing the degradation rate of pure iron stent for widely used.As an alloying component, zinc can improve the degradation rate of pure iron because of its preferable biocompatibility and lower electrode potential. However, the physical properties of iron and zinc have much difference. So it’s hard to get homogeneous Fe-Zn alloy by traditional melting method. In this paper we prepare electroforming iron-zinc alloys with different zinc content and research the surface morphology and cross-section morphology by SEM. What’s more, the phase transformation, mechanical property and degradation property are also researched.The results showed that during electroforming process the alloy content can be adjusted by controlling the concentration of zinc ion in the electrolyte. The alloys with smooth surface can be prepared by using pulse electroforming and adding a small number of additives. The electroforming Fe-15Zn alloy has a smooth surface, super mechanical property and a fine layer by layer cross-section morphology by using high frequency and high current electroforming. The pulse electroforming Fe-Zn alloys are all consist of crystalline a phase without other phases. What’s more, the zinc atoms are all dissolved in the iron lattice and a kind of iron-zinc solid solution is formed. Therefore, the electroforming process is a kind of special preparing method that can expand a phase field to the room temperature. So the electroforming iron-zinc alloys are in a metastable state and difficult to resolve in room temperature. By comparing with pure iron, the electroforming iron-zinc alloys have a better biodegradation property. The electroforming Fe-lOZn has the lowest electrode potential and the fastest degradation rate which is almost twice of pure iron. In all, the electroforming Fe-Zn alloys have a better biodegradable property than pure iron and need more studying in the future.