Study Of Corrosion Behavior Of Deformed Medical Magnesium Alloy In Hank’s Simulation Body Fluids

Magnesium and magnesium alloys as metal-based bio-medicalmaterial is subjected to widespread concern in recent years. Magnesium alloys have broad prospects in the medical field. However, the plastic deformation of the alloy is not easy. And the corrosion resistance of this kind of alloy is poor. This paper chose alloying elements Zn and Ca which is beneficial to humans as alloy component refining the Mg-1Zn-xCa (x=0.25,0.5) alloy, The purpose is to explore the effects of different deformation conditions on the corrosion resistance of magnesium alloys.This experiment take Mg as solvent, Zn and Ca as solutet. Two kinds of degradable ternary Mg-1Zn-xCa alloys with Ca contents of0.25%and0.5%, were fabricated by the protection of the flux method. Doing the extrusion deformation experiments of Mg-1Zn-xCa alloys with Ca contents of0.25%and0.5%are subjected different extrusion pressure. The Deformation rate of this alloy is0,6%, and12%. Do corrosion experiment at constant temperature37℃, taking the different deformed magnesium alloys for corrosion materials and simulated body fluid as aggressive medium. Corrosion time from0to32days. Study the influence that different deformation rate to Mg-1Zn-Ca(x=0.25,0.5) alloy organization and corrosion resistance, using microstructure observed, Macro corrosion observed, determination of the corrosion rate and electrochemical analysis method.The microstructure experimental results show that Mg-1Zn-xCa(x=0.25,0.5) alloys grain were refining with the increasing of deformation rate(0,6%,12%). Alloys composition include α interstitial, MgZn and Mg2Ca; Macro corrosion morphology showed that corrosion resistance of Mg-1Zn-0.25Ca subjected12%is best; The corrosion rate of corrosion test indicated that corrosion rate of Mg-1Zn-0.25Ca alloys subjected12%is slowest, its average corrosion rate is4.07×10-3g.cm-2.d-1. The average corrosion rate of it in casting condition is about6times. The corrosion resistance of Mg-1Zn-0.25Ca subjected12%is best. Electrochemical results show, Mg-1Zn-xCa(x=0.25,0.5)alloys subjected12%Ecorr and polarization resistance is the highest, and its polarization current density is the lowest. So this condition of alloy shows an enhanced corrosion resistance with the increasing of deformation rate. The corrosion Law of Mg-1Zn-0.5Ca alloy system is the same with the Mg-1Zn-0.25Ca above-mentioned. The comparison of the two, in the same conditions of deformation, the corrosion resistance of deformed Mg-1Zn-0.25Ca is superior than the corrosion resistance of the deformed Mg-1Zn-0.5Ca alloy.