The research project of teachers in Anhui University of Technology reveals the mechanism of rare earth nitrification and forcing

    Recently, anhui University of Technology on behalf of the interface Engineering Research Center of Professor Zhang Shihong's team of a new study, through the first principle study of rare earth elements on the absorption and diffusion of nitrogen atoms on the surface of the body core cubic iron, revealed the rare earth nitrification drive mechanism.The paper was published on the international top publication in the field of metal materials, Acta Materialia, with the title "First Principles calculation study on the Effect of Rare earth doping on the Adsorption and diffusion of Nitrogen on the Surface of Fe: Revealing the mechanism of catalytic Nitrification".

    It is reported that rare earth in carburizing, nitriding, spraying and other surface treatment technology has a wide range of applications.Rare earth assisted nitriding has been proved to be helpful to promote the permeation rate, increase the thickness of permeation layer and improve the performance of permeation layer.However, the mechanism is unclear.

    It is known that the bulk structure and surface structure properties of volumetric cubic iron were calculated, and the adsorption properties of nitrogen were calculated.The occupation of rare earth elements in volume-centered cubic iron was simulated and the adsorption of nitrogen atoms on the surface of volume-centered cubic iron doped with rare earth elements was calculated.Strong LA-N effect was found through the change of bader charge and structure after relaxation, which explained the increase of nitrogen adsorption energy after DOPING La element.The adsorption of nitrogen atoms on the core cubic iron subsurface was also calculated, and it was found that the doping of rare earth elements was helpful to the reduction of the diffusion barrier.The catalytic mechanism of rare earth La and Ce was summarized.

    This research will provide insight into the role of rare earths in surface treatment technology, provide theoretical support for the optimization of rare earth surface treatment technology, and provide an example for first Principles to reveal the microscopic mechanism of surface treatment.