Corrosion Behavior of Magnesium Based Foam Structure in Hank’s Solution

Metal foam is a new class of materials with promising applications and a uniquecombination of physical, chemical, and mechanical properties. The purpose of biodegradableimplants is to support tissue regeneration and healing in a particular application by materialdegradation and implant replacement through the surrounding tissue. Magnesium alloys areexpected to be degraded in the body and its corrosion products not deleterious to thesurrounding tissue. In the present study, the foam metal was manufactured via powdermetallurgy with a different variation of sintering temperature and TiH2 used as a foaming agentwhich are added to Mg-1Ca-3Zn alloy as much 3 persen wt TiH2. The sintering temperatures were500, 550 and 600 °C with a constant holding time of 5 hours. It’s critical that the sinteringtemperature is carefully selected in consideration of their corrosion behavior. This paperreports the study of the behavior of the Mg-Ca-Zn alloy metal foam which evaluated by SEM,EDX, and electrochemical corrosion test in Hank’s solutions. After exposure, the SEM resultof Mg-Ca-Zn-3TiH2 to Hank’s solution, a volcano-like structure is formed. The streams of H2bubbles form at local sites on the Mg alloy surface where electrochemical reactions are takingplace, leading to the particular structure with around shape and often with a hole in the center.The corresponding EDS result maps reveal enrichment of O, Ca, P and Mg as corrosionproduct. Potentiodynamic polarization experiments conducted at 37 °C and pH 7.4 indicatedthe increased biodegradation rates resulted from porous structure of foam samples. Corrosionrate in 500oC sintering temperature were 1.99 millimiles per year (mmpy) with corrosioncurrent density (I corr) 87.3.10-6 A/cm2, corrosion rate in 550 °C sintering temperature were2,16 mmpy with Icorr 94.4.10-6 A/cm2 and rate in 600 °C sintering temperature were 2.41mmpy with Icorr 105.10-6 A/cm2. The results showed that the increasing of sinteringtemperature could influence the corrosion resistance of Mg alloy.Keyword: magnesium, alloy, corrosion, in vitro, Hank’s solution IOP Conf. Series: Materials Science and Engineering 202 (2017) 012035