Study On Nano-phases And Surface Improvement Of Metal Materials By Co-implantation And Co-deposition Methods

The modified surface layer on H13 steel and stainless steel has been studied by means of MEVVA implantation and Filtered Vacuum Arc Plasma Deposition in this paper. An innovated C+Me and Me+Me co-implanted and co-deposited process is developed for the first time. The characteristics of co-implantation and co-deposition and improved mechanisms on the surface of materials have been investigated. The effects of nano-phases and hot atom chemistry in the modified surface layer have been studied. Co-implantation and co-deposition on the surface of H13 steel and stainless steel have been fulfilled successfully by applying the modified cathodes in the experiment. And it became true that more than two elements be simultaneously implanted into or deposited on the surface of matrix.It is the first time to study the effect of surface modification of metal materials by co-implantation. In this experiment, C+Me and Cr+Me cathode materials were used to co-implant into H13 and stainless steel. The results showed that the surface hardness and wear-resistance were improved after C+Ti and C+Mo co-implanting into H13 and stainless steel. The corrosion resistance on the surface of the metal materials was also significantly improved. Comparing C+Ti and C+Mo co-implantation, the effects of surface modification showed better for C+Ti co-implantation. In the case of Cr+Ti and Cr+Mo co-implanted stainless steel, the micro-hardness and wear-resistance as well as corrosion-resistance were also increased effectively. Comparing Cr+Ti and Cr+Mo co-implantation, the specimens of Cr+Ti co-implantation showed a better corrosion-resistance, while the specimens of Cr+Mo co-implantation showed a better pitting corrosion resistance.X-ray diffraction and TEM methods were applied to analyze the microstructure of the co-implanting layer. The results showed that some new phases were formed in the implanted layer after co-implanting. The new phases are mainly alloys, carbides and ceramics. They were uniformly dispersed distribution in the co-implanted layer in a nano-meter size, and thenchanged the surface structure of co-implanting layer. So the surface hardness and wear resistance were increased, and the corrosion resistance were improved as well.The effect of hot atom chemistry on modification of metal using co-implantation is observed in metal for the first time. The Auger electron spectroscopy (AES) was used to examine the element density distribution of the C+Ti co-implantation. It was found the C density distribution is much high than the calculated figure. It is also higher than that of C single implantation and Ti+C dual-implantation specimens in AES. The study showed that it is the result that the effect of hot atom chemistry in co-implantation is further enhanced correspoding to dual-implantation and single implantation.Ti+C+N co-depositing experiments were carried out by Filtered Vacuum Arc Plasma Deposition for the first time. After co-depositing of Ti+C+N, a uniform and compact TiC07N03 ceramic film has been formed on the surface of H13 steel. This layer greatly contributed to increase the wear resistance and corrosion resistance: The surface friction coefficient reduced by 3.5 times. And the pitting corrosion potential increased by 285mV. Especially, a very good corrosion resistance has been obtained in Hac/NaAc solution. The critical current density icp was almost near zero. Microstructure analysis showed that the co-deposited layer was mainly composed of TiC07N03 ceramic phase and TiO oxide.The comparison of co-implantation to dual-implantation has been made, and it is found that the effect of surface modification for co-implantation is better than that of dual and single implantation. So the conclusion can be made that co-implantation is the most effective to modify surface properties of metal in the three implantation methods.