A novel biodegradable high nitrogen iron alloy with simultaneous enhancement of corrosion rate and local corrosion resistance

To improve the corrosion rate and suppress the local corrosion, a novel biodegradable high nitrogen (N) FeMnN alloy was developed, and the effects of N content on the corrosion behaviors were systematically investigated. It was found that, as the N content increased, the corrosion rate was significantly enhanced in both Hank's solution and simulated gastric fluid. Meanwhile, as the N content increased, the size and depth of pits decreased obviously, and the number of pits increased, which presented a more uniform corrosion morphology. X-ray photoelectron spectroscopy (XPS) results indicated that N existed in the form of NH4+ in the corrosion products and [FeN] clusters in the matrix. The [FeN] clusters would simultaneously improve the corrosion rate and suppress the local corrosion, which provides a new perspective for the development of biodegradable Fe alloy.