Study of Titanizing the Surface of Copper Substrates by the Double Glow Discharge Plasma Surface Alloying Technique

This paper discusses a study in which Ti surface alloying has been performed on copper substrates by means of a double glow discharge plasma surface alloying technique. The micro-structure, the phase structure, the micro-hardness and the distribution of Ti concentration of alloying layer were investigated in detail by XRD, SEM and so on. The effect of process parameters on the alloying layer was studied. The experimental results show that a Ti solid solution with the precipitation Cu4Ti alloying layer has been formed on the copper surface. The thickness of the alloying layer is about 120 μm and the surface titanium concentration gradually decreases from ω （Ti） = 87% to ω （Ti） = 4%. The micro-hardness of the alloying layer is between 300 HV-800 HV. Source sputtering, surface absorption, ion bombarding and high temperature diffusion are the major factors that affect the alloying layer.

Surface alloying of Cu with Ti by double glow discharge process

The surface of pure copper alloyed with Ti using double glow discharge process was investigated. The morphology, structure and forming mechanism of the Cu-Ti alloying layer were analyzed. The microhardness and wear resistance of the Cu-Ti alloying layer were measured, and compared with those of pure copper. The results indicate that the surface of copper activated by Ar and Ti ions bombardment is favorable to absorption and diffusion of Ti element. In current experimental temperature, as the Ti content increases, the liquid phase occurs between the deposited layer and diffused layer, which makes the Ti ions and atoms easy to dissolve and the thickness of Cu-Ti alloying layer increase rapidly. After cooling, the structure of the alloying layer is composed of CuTi, Cu4Ti and （Cu（Ti）） solid solution. The solid solution strengthening and precipitation strengthening effects of Ti result in high surface hardness and wear resistance.

Corrosion property of copperized layer on Zr formed by double glow plasma surface alloying technique

Zr and its alloys have excellent mechanical properties as new structural material,but in specific application environment,its corrosion resistance still needs to be further explored.In this work,double glow plasma surface alloying technique was used for copperizing on pure Zr surface.Besides,X-ray diffraction（XRD）,scanning electron microscope（SEM） and energy dispersion spectrum（EDS） were employed to characterize the samples.Furthermore,research was also conducted on the polarization curve of the samples in different solutions.Copperizing on surface can improve corrosion resistance of pure Zr in 3.5 % Na Cl and 0.5 moláL-1Na OH solutions.Especially in 0.5 moláL-1Na OH solution,the corrosion resistance can achieve significant improvement.However,copperizing has no influence on the improvement of corrosion resistance of pure Zr in 0.5 moláL-1H2SO4 solution.The results may provide new insight into way for improving the corrosion property of zirconium alloys.

Quantitative Analysis on Carbon Migration in Double-Glow Discharge Plasma Surface Alloying Process

Carbon migration is of great significance in double-glow discharge plasma surface alloying process, but literature of quantitative analysis about carbon migration is relatively scarce. In this paper differential equations of the carbon and metal concentration distribution were established. By means of differential equations carbon migration was described and a numerical solution was acquired. The computational results fit the experiment results quite well.

Characterization of a New DC-Glow Discharge Plasma Set-Up to Enhance the Electronic Circuits Performance

The (DC-GDPAU) is a DC glow discharge plasma experiment that was designed, established, and operated in the Physics Department at Ain Shams University (Egypt). The aim of this experiment is to study and improve some properties of a printed circuit board (PCB) by exposing it to the plasma. The device consists of cylindrical discharge chamber with movable parallel circular copper electrodes (cathode and anode) fixed inside it. The distance between them is 12 cm. This plasma experiment works in a low-pressure range (0.15 - 0.70 Torr) for Ar gas with a maximum DC power supply of 200 W. The Paschen curves and electrical plasma parameters (current, volt, power, resistance) characterized to the plasma have been measured and calculated at each cm between the two electrodes. Besides, the electron temperature and ion density are obtained at different radial distances using a double Langmuir probe. The electron temperature (KTe) was kept stable in range 6.58 to 10.44 eV;whereas the ion density (ni) was in range from 0.91 × 1010 cm−3 to 1.79 × 1010 cm−3. A digital optical microscope (800×) was employed to draw a comparison between the pre-and after effect of exposure to plasma on the shaping of the circuit layout. The experimental results show that the electrical conductivity increased after plasma exposure, also an improvement in the adhesion force in the Cu foil surface. A significant increase in the conductivity can be directly related to the position of the sample surfaces as well as to the time of exposure. This shows the importance of the obtained results in developing the PCBs manufacturing that uses in different microelectronics devices like those onboard of space vehicles.

A Study of Multi-Permeating TiN/Ti Alloying Layer Using Plasma Surface Alloying Technology

TiN/Ti multi-permeating alloying layer has been formed on the low carbon steel by means of the double glow-discharge plasma surface alloying technique and hollow-cathode effect. The alloying layer was detected by axiovert 25 CA optical microscope with computer analyzing software （LEC）, GDA-2 glow discharge spectroscopy （GDS）, X-ray diffraction （XRD） and galvanochemical method. The results showed that the thickness of TiN/Ti multi-permeating alloying layer was about 10μm, the content of Ti on the surface was up to 63.48 wt% and the content of N was up to 12.46 wt%. The atom Ti and N concentrations changed gradually across the depth of the alloying layer and the preferred orientation of TiN/Ti alloying layer was crystal surface （200）. The multi-permeating alloying layer and substrate were combined through metallurgy. The surface appearances of the multi-permeating alloying layer were uniform and of a compact cellular structure. The hardness of the surface was about 1600-3000 HV0.1. The corrosion resistance of the permeating TiN/Ti alloying layer in 0.5 mol/L H2SO4 solution was greatly increased and the corrosion rate was only 0.3082 g/m^2. h.

Generation scenarios of anodic structures and experimental realization of turbulence in unmagnetized plasma

In the present work,we report development of a DC glow discharge plasma(GDP)set-up to study controlled evolution of anodic structures having distinctive geometry,size and layers,generated in front of a positively biased electrode,submerged in unmagnetized plasma.For such an anodic structure,we have also investigated the condition under which the turbulence is triggered.Characteristic of these structures,generated in front of a positively biased electrode,depends on multiple parameters such as the ratio of anode to cathode size,electrode separation,gas pressure,biasing configuration such as anode bias,cathode bias and grounding schemes.We attempted to classify different anodic structures observed experimentally,as anode glow,fireball,anode spot,double layer and multiple double layers(MDLs)based on its physical characteristics.Among these structures the present investigation is focused on MDLs.The number of layers,observed in MDLs varied from as high as six to as low as zero,by controlling the operating discharge parameters,externally.Diagnostics were carried out using Langmuir probe.The analysis of floating potential fluctuations corresponds to a multiple anodic structure showed emergence of turbulence,at its critical stage,satisfying condition for self-organized criticality(SOC).This was identified with three slopes observed in the power spectrum,resembling the sand-pile model.Though,the GDP is completely different from that of the magnetically confined plasma,the nature of turbulence observed with SOC,is very similar to that observed in the scrape of layer of fusion devices.Therefore,the present investigation could provide new approach to study turbulence of similar nature,under an experimental condition that is free from the complexities of complicated field geometries used in confinement devices.

射频等离子体对合成低碳醇用CuCoAl催化剂的改性作用

采用共浸渍法制备了CuCo/γ-Al2O3催化剂,应用射频等离子体技术对催化剂进行改性处理。以CO加氢合成低碳醇为模型反应对催化剂进行活性评价,通过X射线物相分析(XRD)、氢氧滴定(HOT)、CO程序升温脱附(CO-TPD)和程序升温还原(TPR)等技术对催化剂进行表征,研究了射频等离子体技术强化处理对催化剂结构、吸附性能和还原性能的影响。结果表明,等离子体技术改性处理提高了催化剂活性组分的分散度,细化了铜物种的晶粒尺寸,增加反应活性位并调变了活性位对吸附物种的吸附强度,改进了催化剂的还原性能,等离子体改性处理的催化剂比未处理的样品CO加氢反应活性和低碳醇的时空产率显著提高。

纯铜双层辉光离子渗钛组织形成机理及性能分析

采用双层辉光离子渗金属技术对纯铜进行了渗钛处理。用配有能谱仪(EDS)的扫描电子显微镜(SEM)、X射线衍射仪和透射电子显微镜对合金层的显微组织形貌、钛含量分布、相组成及相结构类型进行了观察与测定,对合金层的形成机理进行了探讨,并对其性能进行了对比测定。结果表明:渗钛层由合金层和扩散层组成,合金层主要由TiCu+(Cu)固溶体+TiCu4构成,TiCu4为D1a型有序相,TiCu为B2型有序相,扩散层为(Cu)固溶体。渗钛处理后纯铜的表面得到显著强化。

纯铜加弧辉光离子渗钛的研究

介绍了加弧辉光离子渗钛新技术 ,利用此技术在纯铜表面形成一层均匀的渗钛层 ,探讨了纯铜渗钛后渗层的组织特征、渗层合金成分分布。

纯铜双层辉光离子临界区渗钛研究

利用双层辉光离子渗金属技术在纯铜表面制备了铜钛合金层。实验结果表明 ,合金层由以铜钛化合物为主的表层和钛在铜中α固溶体与弥散分布的Cu4 Ti有序相的次表层组成。在源极与工件间距固定的条件下 ,表层成分受源极电压、工件电压和温度的影响 ,次表层厚度主要受温度和时间影响。在扩渗初期 ,轰击离子的强度对钛元素有催渗作用。源极电压与工件电压之比V源 V工 ≥ 2 ,气压选在(2 5～ 4 0 )Pa有利于铜钛合金层的形成。纯铜渗钛虽可使材料表面强化 。

射频等离子体技术制备合成低碳醇用铜钴基催化剂

采用射频等离子体技术制备了CO加氢合成低碳醇用新型CuCo/ZrO2催化剂,研究了等离子体气氛氮气、氢气和先氮气后氢气处理对催化剂结构和性能的影响,并应用BET、XRD、XPS、TG和TPR技术对催化剂进行了表征.与常规焙烧制得的样品相比,射频等离子体技术制备的催化剂可有效抑制烃类生成,提高总醇选择性,大幅提高反应活性和低碳醇的时空收率.表征结果显示,等离子体技术使催化剂前驱体在低温下分解形成活性相,显著提高了催化剂比表面积,促进催化剂活性组分晶粒细化并提高其分散度,催化剂表面的铜含量增加.

Ti-Cu表面阻燃钛合金研究

利用双层辉光离子渗金属技术,在Ti-6Al-4V的表面渗入Cu元素,在其表面形成Ti-Cu阻燃合金层。阻燃合金层的成分及硬度呈梯度分布,显微组织为基体组织加弥散分布的Ti2Cu金属间化合物。初步阻燃试验证明,渗铜合金层起到了预期的阻燃效果。

纯铜双层辉光离子渗镍研究

介绍了采用双层辉光离子渗金属技术在纯铜表面制备Cu Ni合金层的新方法 ,讨论了Cu Ni合金层的组织、成分和性能特点 ,分析了辉光放电条件、源极溅射率及表面金属势对Cu Ni合金层形成过程的影响。试验结果表明渗层厚度及渗层质量与辉光放电条件有关 ,在保证渗金属温度的前提下 ,应尽可能提高源极电压 ,降低试件电压。此外 ,该工艺还具有渗速快、效率高。

钛合金表面双层辉光离子渗铝的研究

利用双层辉光渗金属技术,以铝为源极、TC4(Ti-6Al-4V)为阴极、氩气为工作气体,依靠辉光放电和不等电位空心阴极效应在TC4表面形成合金层。采用X射线衍射和辉光放电光谱分析了合金层的相组成及渗层内Al元素的分布,并对其进行硬度测试。结果表明:渗层由Ti3Al和α-Ti组成;铝的含量可达18%;渗层厚度可达13滋m;其硬度比经渗铝处理后的有了较大程度的提高。

双层辉光离子渗金属技术特点分析

详细介绍了双层辉光离子渗金属技术的基本原理、放电模式及渗金属过程。并就该技术的优势和特点进行了理论分析。结果表明,该技术在表面合金化技术领域中,是适合于高熔点金属表面合金化和采用高熔点金属对铁基或某些熔点较高的有色金属表面进行合金化的实用工艺。

射频等离子体技术制备合成低碳醇用新型Cu-Co/SiO_2催化剂(英文)

采用射频等离子体技术制备新型Cu-Co/SiO2催化剂.与直接焙烧制备的样品相比,射频等离子体处理提高了催化剂的比表面积,显著增大了活性物种Co的表面含量,有效改进了催化剂的还原性能.以CO加氢合成低碳混合醇为模型反应,在563K,5.0MPa,6000h-1,V(H2)∶V(CO)=1.6的条件下,等离子体处理和等离子体处理后再焙烧样品比673K焙烧样品的催化活性提高30.46%和65.30%,低碳醇的时空收率分别提高58.22%和76.11%.

双辉等离子表面冶金Ti-Cu阻燃合金的制备工艺

为解决整体阻燃钛合金存在的比强度低、加工性差及价格昂贵等问题, 利用双层辉光离子渗金属技术,在Ti 6Al 4V的表面渗入Cu元素, 在其表面形成Ti Cu阻燃合金层。研究了温度、保温时间、源极电压、工件电压、极间距等工艺参数对渗层显微组织、成分及厚度的影响, 得出了适合的工艺参数。870 ℃渗铜 3.5 h, 渗层厚度可达到200μm以上。阻燃合金层的成分呈梯度分布, 显微组织为基体组织加弥散分布的Ti2Cu金属间化合物。初步阻燃实验证明, 渗Cu合金层起到了预期的阻燃效果。

双层辉光离子渗金属技术特点

分析了双层辉光技术的特点,指出该技术在材料表面合金化方面,是一项适合于高熔点金属表面合金化和采用高熔点金属对铁基或某些熔点较高的有色金属材料进行表面合金化的工艺技术。

辉光放电等离子体辅助碱浸铜冶炼烟灰中铜砷分离

采用辉光放电等离子体辅助Na_2S-NaOH浸取体系对铜冶炼烟灰(简称"烟灰")进行研究,在放电时间10min、放电功率500 W、放电压强150 Pa、极板间距0.9 cm的条件下,砷的浸出率为92.52%,铜的浸出率为7.76%,实现了砷和铜的有效分离。采用该方法处理后烟灰中的砷从7.11%降到0.45%,铜从2.62%变为2.42%,为烟灰的进一步利用创造了条件。XPS、XRD和重金属形态分析的综合分析结果表明,辉光能将As(Ⅲ)氧化为As(Ⅴ)、Cu(Ⅰ)氧化为Cu(Ⅱ),且在碱性条件下As(Ⅴ)比As(Ⅲ)更易浸出。因此,辉光放电预氧化有利于砷和铜在碱浸体系中选择性分离。