Structure And Properties Of Modified Layers By Plasma Based Ion Implantation On Magnesium Alloy

In this paper, magnesium alloy AZ31 has been treated by nitrogen-plasma based ion implantation (N-PBII). And we deposited DLC on a part of the nitrogen-implanted samples. The effects of process parameters such as implantation voltage, implantation dose after implantation on the composition, microstructure, frictional behaviors and corrosion were studied systematically.The composition depth profile and chemical states of nitrogen-implanted layers were determined using X-ray photoelectron spectroscopy (XPS). The nitrogen-implanted sample after deposite DLC was characterized synthetically by Raman spectroscopy. The microstructure of nitrogen-implanted layers was observed by transmission electron microscopy (TEM). To observe surface morphology and roughness, atomic force microscopy (AFM) was also used. The Scanning electron microscope (SEM) were also used to investigate the wear track and the corrosion modality. Moreover, tribological and electrochemical corrosion behaviors have been investigation systematacially.The results showed that compared with the substrate, the roughness of the implanted samples were increased. And with the implantation dose increase the roughness of the sample also increase. The outmost portion of the nitrogen-implanted lay consists of MgO. And there is an intermediate lays composed of MgO, Mg3N2, Mg and a little dissolving nitrogen between the outer layer and the metallic substrate. And in the intermediate lays, the contents of MgO and Mg(OH)2 decrease with the depth increase while the content of Mg increase. And the nanometer grains of Mg3N2 and MgO disperse distributed in the amouphous structure. The nanohardness of the implanted samples are higher the the substrate. And the nanohardness of the sample deposited with DLC is higher than the nitrogen-implanted sample; it is about fourfold of the substrate. The friction coefficients of the nitrogen-implanted sample decreasing marked against with hardend GCr15 steel ball in condition of unlubrication and air environment. Th friction coefficients were about 0.3~0.4. It was about 0.1~0.2 for the DLC deposited samples in the same condition. And the lowest ratio of wear and tear is about zero. And compared with substrate, the corrosion resistances of the...