Duplex Surface Treatment due to Combined ECR Plasma Nitriding and Ceramic Coatings

(1)高密度等离子体源电弧离子镀（AIP）系统的研制将2.45GHz微波引入等离子体端口，利用稀土磁体通过石英窗口产生尖形磁场。该等离子体端口设置在AIP设备的真空室的上凸缘处。在该系统中，样品被放置在工作台上，工作台可以加热到600 ℃，偏压到-1kV。在该系统中进行了等离子渗氮和陶瓷涂层。（2）复合表面处理钢的力学性能研究了TiN（Hv 2200）和CrN（Hv 2000）的氮化物膜、TiC（Hv 3000）的碳化物膜、TiH_2（Hv 500）的氢化物膜、TiO_2（Hv 1200）的氧化物膜和DLC（Hv 2600）的类金刚石膜。双相处理钢的机械性能如下。(1)TiN或CrN涂层试样等离子渗氮后表现出最好的耐磨性，即使在重载。(2)陶瓷膜大多表现出良好的耐蚀性。特别是TiH_2膜的腐蚀电流密度很小。(3)与未处理的试样相比，双重处理试样的疲劳极限大大提高。渗氮层的质量对疲劳抗力最有效。

(1) Production of Arc Ion Plating (AIP) system with high density plasma source2.45 GHz microwave was introduced into the plasma port where the cusp-type magnet field was generated by utilizing a rare earth magnet through a quartz window. This plasma port was set up at an upper flange of a vacuum chamber of AIP equipment. In this chamber, the specmens were mounted on the stage which could be heated up to 600ﾟC and biased untill -1 kV.Plasma nitriding and ceramic coating were done in this system.(2)Mechnical properties of duplex suraface treated steelsNitride films of TiN (Hv2200) and CrN (Hv2000), carbide film of TiC (Hv3000), hyderide film of TiH_2 (Hv500), oxide film of TiO_2 (Hv1200) and diamond like carbon film of DLC (Hv2600) were examined in this study. The mechanical properties of the duplex treated steels are as follows. (1) TiN or CrN-coated specimens after plasma nitriding showed the best wear resistance even under a heavy load. (2) Ceramic films showed good resistance tocorrosion mostly. Especially, we found the corrosion current density of TiH_2 film is very small. (3) The fatigue limit of the duplex treated specimens increased largely compared to that of the untreated one. The quality of the nitrided layr is most effective according to the fatigue resistance.