PIIID复合强化处理轴承钢表面TiN膜层的XPS表征

用等离子体浸没离子注入与沉积(PIIID)复合强化新技术在AISI52100轴承钢基体表面成功合成了硬而耐磨的氮化钛薄膜。膜层表面的化学组成和相结构分别用X射线衍射(XRD)和X射线光电子能谱(XPS)表征;膜层表面的原子力显微镜(AFM)形貌显示出TiN膜结晶完整，结构致密均匀。XRD测试结果表明，TiN在(200)晶面衍射峰最强，具有择优取向。Ti(2p)的XPS谱峰泰勒拟合分析揭示出，Ti(2p_1/2)峰和Ti_2p3/2峰均有双峰出现，表明氮化物中的Ti至少存在不同的化学状态;N(1s)的XPS谱峰在396.51, 397.22和399.01 eV附近出现了三个分峰，分别对应于TiNO_y,TiN和N—N键中的氮原子。结合O(1s)的XPS结果，证实膜层中除生成有稳定的TiN相外，还有少量钛的氧化物和未参与反应的单质氮。整个膜层是由TiN，TiO₂,Ti—O—N化合物和少量单质氮组成的复合体系。

XPS Characterization of TiN Layer on Bearing Steel Surface Treated by Plasma Immersion Ion Implantation and Deposition Technique

Titanium nitride (TiN) hard protective films were fabricated on AISI52100 bearing steel surface employing plasma immersion ion implantation and deposition (PIIID) technique. The TiN films were characterized using a variety of test methods. Atomic force microscope (AFM) revealed that the titanium nitride film has extremely smooth surface, very high uniformity and efficiency of space filling over large areas. X-ray diffraction (XRD) result indicated that （200） crystal face of titanium nitride phase is the preferred orientation and three kinds of titanium components exist in the surface modified layer. Tailor fitting analysis of X-ray photoelectron spectroscopy (XPS) combined with Ar ion etching proved that Ti2p1/2 and Ti2p3/2 have two peaks in the titanium nitride film layer, respectively. It is shown that different chemical state exists in titanium compound. N(1s) bond energy of XPS has also three fitting peaks at 396.51, 397.22 and 399.01 eV, corresponding to the nitrogen atom in TiNxOy， TiN and N—N, respectively. Combined with the XPS Tailor fitting analysis results of O(1s) bond energy, it was shown that there is a large amount of titanium nitride phase in addition to a small amount of simple substance nitrogen and oxide of titanium in the surface layer. The whole film system is made up of TiN, TiO2, N—N and Ti—O—N compound.