GCr15钢等离子体基离子注入Ti和C混合层的XPS研究

用Ｘ射线光电子谱研究了ＧＣｒ１５轴承钢不平衡磁控溅射沉积Ｔｉ，继之等离子体基离子注入碳的等离子体基离子注入混合层的Ｃ，Ｔｉ浓度深度分布及其化学结构。表明混合层的最表层为碳沉支，其Ｃｌｓ谱峰呈类金刚石特征，喇曼光谱肯定辽一特征。碳沉积层下面为Ｃ－Ｔｉ混合区，Ｔｉ和Ｃ各以游离态和化合物态存在。混合层内Ｔｉ和Ｃ浓度沿层深连续变化，无突变区，在原Ｔｉ沉积层与基材轴承钢发生反冲增强扩散现象。     

等离子体基离子注入制备TiN膜的成分结构

采用Ti、N等离子体基离子注入和先在基体表面沉积纯钛层然后离子注氮混合两种方法在铝合金基体上制备了TiN膜.利用XPS分析了两种方法制备TiN薄膜的成分深度分布和元素化学价态,并用力学性能显微探针测试对比了TiN膜的纳米硬度.研究表明:两种方法制备的薄膜均由TiN组成,Ti、N等离子体基离子注入薄膜中Ti/N≈1.1,而离子注入混合薄膜中Ti/N≈1.3,Ti、N等离子体基离子注入薄膜表面区域为TiN和TiO2的混合组织,TiN含量多于TiO2,离子注入混合薄膜表面主要是TiO2;Ti、N等离子体基离子注入所制备的薄膜的纳米硬度峰值为12.26 GPa,高于离子注入混合的7.98 GPa.     

等离子体基低能离子注入技术的研究与发展

将低能离子注入技术引入等离子体基离子注入,一方面利用低能离子注入的低能优势,另一方面利用等离子体基离子注入的全方位优势,开发出等离子体基低能离子注入技术。等离子体基低能离子注入技术包括等离子体基低能氮、碳离子注入和等离子体源低能离子增强沉积两类工艺。低能离子的注入能量（０．４～３ ｋｅＶ）达到常规等离子体热化学扩散处理的电压范围,而工艺温度（２００～５００℃）则降至常规离子注入的上限温度范围。通过大量的工艺实验研究,实现了工艺过程的优化和控制,完成了对等离子体基低能离子注入改性铁基材料的金属学问题及物理、化学和力学性能的系统研究。证明了等离子体基低能离子注入技术满足铁基材料的表面改性要求。同时具有产业化发展潜力。     

正方形钛试样表面等离子体基离子注入氮的保留剂量研究

为了研究靶形状对等离子体基离子注入均匀性的影响，应用Auger电子能谱(AES)剖面分析，测量并计算了正方形靶表面排布的Ti试样经氮等离子体基离子注入(PBⅡ)的保留剂量分布．由于N的Auger电子发射能量与Ti的完全重合，而且表面氧化层对Ti的Auger跃迁产生很大的影响，因此应用AES对于氮等离子体基离子注入钛基金属进行化学分析变得较为复杂．本文探讨了一种既解决峰位重叠问题又考虑氧化层影响的方法，从而能够根据，AES溅射剖面分析数据计算浓度深度曲线，并获得保留剂量．正方形靶表面不同位置处的剂量测算结果表明，靶的形状对于保留剂量有着很大的影响，造成剂量呈梯度分布．同时还发现，Ti氧化层随着保留剂量的增大而增厚。     

Ti＋C双离子注入GCr15钢表面改性工艺研究

采用Ti＋C双离子注入GCr15轴承钢,使其表面硬度增加,摩擦系数降低,增强了GCr15钢表面抗磨损特性。同时发现,离子注入时金属基体的温升效应对表面改性效果具有显著的影响。通过对比分析,获取了最佳处理工艺参数。     

金属等离子体浸没离子注入改善9Cr18轴承钢表面耐磨性的研究

采用新改进的阴极弧金属等离子体源 ,对 9Cr18轴承钢进行了金属等离子体浸没离子注入 (PIII)处理。首先将Ti,Mo和W离子分别注入到 9Cr18钢的表面 ,然后再对其进行N等离子体浸没离子注入 ,从而在 9Cr18钢表面形成了一层超硬耐磨的改性层。对PIII处理后的试样进行了显微硬度和磨损特性测试 ,结果表明 ,经PIII处理后的试样表面的显微硬度和耐磨性显著提高 ,而其中经Ti和Mo注入再进行N离子注入的试样效果更为明显。与仅进行N离子注入的试样相比 ,金属加N离子注入的试样表面耐磨性提高幅度更大 ,表明金属PIII在改善 9Cr18钢表面性能方面具有广阔的应用前景。XPS分析结果表明 ,PIII处理后试样表面形成了超硬的氮化物相 ,它们在改善材料表面特性中起到了重要的作用。     

Ti6Al4V等离子体浸没式离子注入

采用新型等离子体浸没式离子注入技术,对Ti6Al4V合金进行氮离子注入.对注入层的成分、组织和性能的分析表明,注入层中氮浓度的分布具有类高斯分布特征,在注入层中有TiN和非晶态相形成.注入层的显微硬度和摩擦性能得到了明显的改善.     

GCr15轴承钢表面PⅢD处理膜层膜基结合力的研究

采用等离子体浸没离子注入沉积(PIIID)技术在GCr15轴承钢表面形成TiN薄膜,并采用划痕法对不同参数条件下膜层的膜基结合力进行了测量.结果发现:适当的氩离子溅射清洗和加入合适的过渡层可以提高膜基结合力,而且膜基结合力也会随着注入电压和注入量与沉积量比例的变化而改变.     

金属等离子体浸没离子注入改善9Cr18轴承钢表面耐磨性的研究

采用新改进的阴极弧金属等离子体源,对９Ｃｒ１８轴承钢进行了金属等离子体浸没离子注入（ＰⅢ）处理,首先将Ｔｉ、Ｍｏ和Ｗ离子分别注入到９Ｃｒ１８钢的表面,然后再对其进行Ｎ等离子体浸没离子注入,从而在９Ｃｒ１８钢表面形成了一层超硬耐磨的改性层。     

9Cr18轴承钢氮等离子体浸没离子注入表面改性工艺及机理的研究

采用不同怕等离子体浸没离子注入工艺对９Ｃｒ１８轴承钢进行了氮离子注入,结果发现,不同条件下的氮离子注入均能显著提高９Ｃｒ１８钢表面的显微硬度和耐磨性,同时耐磨蚀性也明显改善。实验分析结果表明、氮离子注入后试样表面形成了大量的氮化物相,它们在改善材料表面特性中起到了关键的作用。     

脉冲真空电弧离子镀在不锈钢上沉积类金刚石薄膜的研究

利用脉冲真空电弧离子镀技术在3Cr13不锈钢上制备了类金刚石(DLC)薄膜,通过Raman光谱分析了膜的结构特征,采用摩擦磨损试验机测试了薄膜在不同载荷下的摩擦系数,运用划痕仪研究了膜基的结合强度.结果表明:所镀制的薄膜具有典型类金刚石结构特征,膜中ID/IG为1.33;摩擦系数随着载荷的增大而减小,载荷为5 N,转速120 r/min时的摩擦系数为0.12;Ti过渡层的引入显著地提高了膜基结合力.     

Ultrahigh hardness of carbon steel surface realized by novel solid carburizing with rapid diffusion of carbon nanostructures

In this study, a novel rapid solid carburizing process with a large diffusion depth using nano-diamonds(NDs) was conducted for low carbon steel. Changes of annealed NDs were obtained by Raman spectroscopy and transmission electron microscopy(TEM), and the results suggested that the NDs experience a stripping process before a special solid-reaction with surface iron atoms from steel substrate. Onionlike carbon(OLC) derived from the annealed NDs provided broken graphitic ribbons as carbon sources that accelerated the rate of adsorption and diffusion. Examination of the surface layer at equilibrium using TEM and X-ray photoelectron spectroscopy(XPS) also revealed the special state of carbon, and an ultrafine mixed phase microstructure was obtained by rapid solid-phase transformation. As a result, a surface hardened layer with ultrahigh hardness and a smooth transition region were realized. We believe that these kinds of diamond or graphitic structures with high activity states have an important influence not only on adsorption and diffusion but also on this special solid-phase transformation.     

TiC coatings deposited onto carbon and molybdenum surfaces by electron beam evaporation

TiC coatings were deposited onto graphite and molybdenum substrates by an electron beam evaporation method. A titanium film 1000–10000 Å thick was evaporated onto the graphite substrate which was then heated at 1000 °C for 5 min to form the TiC film by an interdiffusion process. In the case of the molybdenum substrate, a double-layer film consisting of titanium and carbon (Ti/C/Mo) was prepared by evaporation and the subsequent heat treatment was performed at 700 °C or at 1000 °C for 5 min. The properties of the coatings were examined by various surface analysis techniques including Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and Rutherford backscattering (RBS). The atomic ratio of carbon to titanium in these coatings was found to be 0.9. The in-depth profiles obtained by XPS examination showed that the coating prepared at 700 °C had a carbon layer between the TiC layer and the molybdenum substrate, while that prepared at 1000 °C had an Mo₂C layer between the coating and the substrate.     

调制比对C/C多层膜结构及性能的影响

考察了C(硬)/C(软)调制比对多层膜结构和性能的影响。采用磁过滤直流阴极真空弧源沉积技术制备了C/C多层膜,通过Raman光谱对多层膜的结构进行了表征;用硬度计和销盘式摩擦磨损试验机测试了多层膜的硬度及摩擦学性能。结果表明:所制备的多层膜呈现类金刚石结构并具有良好的耐磨性,其摩擦系数均小于0.15;随多层膜中软膜比例的增大,薄膜中sp2簇的数量逐渐增多,薄膜显维硬度呈现下降趋势,多层膜的耐磨性能下降。     

Characterization of carbon/nitroazobenzene/titanium molecular electronic junctions with photoelectron and Raman spectroscopy

Molecular junctions consisting of nitroazobenzene (NAB) chemisorbed to a substrate of pyrolyzed photoresist film (PPF) and a top contact of vapor-deposited titanium were examined with Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The thickness of the NAB layer varied from submonolayer to 4.5 nm, and a thin (1-3 nm) overlayer of Ti was deposited by electron beam deposition. Without Ti, the NAB surface Raman spectrum was sufficiently strong to observe previously unreported modes in the 500-1000-cm(-1) region, and the 1000-1700-cm(-1) region was sufficiently strong to observe the effects of metal deposition. Upon Ti deposition, the intensities of NAB modes associated with the nitro group decreased significantly, and the XPS indicated formation of a Ti-N bond. For the thicker NAB layers (1.9 and 4.5 nm), the intensities of the NO(2) Raman modes partially recovered over a several-day period, but they remain depressed or absent in the submonolayer sample. The results indicate a reaction between condensing Ti atoms and the terminal NO(2) group, probably to form a Ti-nitroso linkage between NAB and Ti. The result is a molecular junction with covalent bonding at both ends in the form of a C-C bond between PPF and NAB and a Ti-N bond to the top contact. The structural implications of the current results are interpreted in the context of recently reported functioning PPF/NAB/Ti molecular electronic junctions. In particular, the reaction between Ti and the nitro group appears to prevent short circuits resulting from incursion of Ti into the NAB layer.     

Carbon layers formed on steel and Ti alloys after ion implantation of C+ at very high doses

Ion implantation is a useful technique to tailor surface properties of steel and Ti alloys. In particular, very high dose C⁺ implantation (in the range of 10¹⁸ ions cm⁻²) offers the possibility of forming carbon layers without a sharp interface with the substrate material. In this study, ion implantation of carbon doses up to 8×10¹⁸ ions cm⁻² has been performed on 440C martensitic stainless steel and Ti6Al4V substrates under similar conditions and tribological and surface analysis results have been compared. Surface hardening occurred for all ion implantation conditions up to doses of 10¹⁸ ions cm⁻²1, 2, 3. Higher doses resulted in a different behaviour for both materials. The stainless steel showed a softening while a twofold hardness increase was maintained in the Ti alloy. Nevertheless, at the higher implanted dose a decrease in hardness was also observed in the Ti alloy. Small area XPS analyses were performed to evaluate the chemical states after ion implantation and establish a relationship with the observed surface hardening. Depth profile XPS analyses showed that for a dose of 4×10¹⁸ ions cm⁻² a carbon layer (with concentration over 85% at. C) was formed in the near surface region for both materials.     

XPS study of the a-C:H/Ti and a-C:H/a-Si interfaces

In this study ultrathin hydrogenated amorphous carbon (a-C:H) films have been grown onto the titanium and amorphous silicon (a-Si) overlayers by direct ion beam deposition using acetylene gas as a hydrocarbon source. X-ray photoelectron spectroscopy (XPS) was used for study of the DLC-Ti and DLC-Si interfaces. It was revealed that a-Si is a good interlayer for improvement of adhesion in the case of diamond-like carbon film deposition onto the steel substrate at room temperature. a-C:H film growth without substantial intermixing occurred on the a-Si. On the other hand, adhesion between the Ti interlayer and the diamond like carbon film was very sensitive to the deposition conditions (presence of the pump oil) as well as structure and stress level of the Ti film. It was explained by strong intermixing between the growing carbon film and Ti. Bad adhesion between the growing DLC film and Ti interlayer was observed despite formation of the TiC. At the same time, formation of the TiO_x was not an obstacle for good adhesion. It is shown that composition of the used hydrocarbon gas, structure of the Ti thin film and mechanical stress in it had greater influence on adhesion with a-C:H film than elemental composition of the Ti interlayer surface.     

9Cr18轴承钢表面不同等离子体浸没离子注入强化处理技术研究

采用不同的等离子体浸没离子注入(PⅢ)工艺在9Cr18轴承钢表面进行了气体、金属、金属加气体的离子注入和碳化钛(TiC)、类金刚石(DLC)薄膜的等离子体浸没离子注入与沉积(PⅢD).对处理后的试样进行了X射线光电子能谱(XPS)、X射线衍射(XRD)、俄歇电子能谱(AES)和拉曼光谱(Raman)分析;测试了处理前后试样的显微硬度、磨痕宽度和摩擦系数.结果表明:处理后试样表面均形成了不同的改性层,且改性层中化学组成和各元素的浓度-深度分布随处理工艺的不同而变化;处理后试样的显微硬度都有较大提高,最大增幅达77.7%;表面摩擦系数由0.8下降到0.16;磨痕宽度减少了23倍;与PⅢ工艺相比,相同参数下,PⅢD处理后的试样表面综合性能更加优异.