双层辉光等离子表面共渗Cr-Ni-Mo-Co工艺研究

采用双层辉光等离子渗金属技术,在工业纯铁表面渗入Cr,Mo,Co等合金元素,可在其表面形成与沉淀硬化不锈钢合金含量及硬度水平相近的合金层。以SEM等对比研究了不同工艺参数下,等离子渗入合金元素后,合金层表面的微观形貌。通过对比不同温度、源极电压所对应的渗层成分及厚度,选择出最优化的工艺参数:源极电压1 350V,阴极电压510～530V,加热温度1 100℃,保温时间5h。     

双辉离子W、Mo、Ti三元共渗特性研究

采用双层辉光离子渗金属技术，对工业纯铁、20钢、45钢和T8钢进行了W、Mo、Ti离子三元共渗，着重探讨了Ti的渗入特性。结果表明，渗层成分、组织因工艺条件不同而异，典型组织为合金沉积层、合金铁素体和合金珠光体。在同样工艺条件下钛元素不易渗入，在渗层中浓度较低，但通过工艺参数和源极成分的合理调整，可获得约2％Ti，W、Mo浓度与高速钢类似的合金铁素体层，为含钛表面冶金高速钢的制备提供了必要条件。     

工业纯铁表面离子W、Mo、Co多元共渗扩散行为

采用双层辉光离子渗金属技术在工业纯铁表面进行W、Mo、Co多元共渗,分别采用0．5、1、2和3h等渗金属时间,研究了合金层中W、Mo、Co含量随渗金属时间的变化规律。研究表明：渗金属初期,合金层中W含量〉Co含量〉Mo含量;渗金属后期,合金层中Co含量〉W含量〉Mo含量。理论分析认为：在渗金属初期,W、Mo、Co扩散主要受各元素原子与空位交换难易程度以及基体表面各元素活性原子量的控制;在渗金属后期,W、Mo、Co扩散主要受各元素在基体中的溶解度的控制。     

双层辉光离子多元共渗中的源极变化

观察了双层辉光渗金属过程中源极溅射后的成分以及形貌 ,利用X射线衍射对源极溅射表面进行了相分析 ,并且用Thermo cale软件进行了相计算。结果表明 :在辉光溅射条件下源极的成分和形貌发生了较大的变化 ,溅射后源极表面主要析出相为 μ相和Laves相 ,用Thermo cale软件热力学相计算结果与X射线衍射结果基本吻合     

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.     

双辉多元共渗与电刷镀复合表面耐蚀渗镀层的研究

在20钢表面电刷镀快速Ni层作为过渡层，然后采用双层辉光离子技术将Ni-Cr-Mo-Cu合金进行多元共渗，对形成的复合镀层在5%HCl溶液中进行了电化学腐蚀性能测试，利用XRD，扫描电镀以及EDX对渗层的组织结构和合金元素及碳元素在渗层中的分布进行了分析，结果表明；预先刷镀快速Ni镀层再进行双层辉光多元渗Ni-Cr-Mo-Cu的复合渗镀层的耐蚀性能明显优于双辉多元渗Ni-Cr-Mo-Cu以及单独电刷镀Ni镀层的耐蚀性能，分析认为，由于双辉多元共渗中的温度效应，使层复合渗镀层具有较好的耐蚀性能。     

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Cu4Ti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(25～40)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，但表面电阻明显增大。     

等离子镍铬表面合金化合金元素利用率研究

采用双层辉光离子渗金属技术在２０钢上进行镍铬共渗处理,对合金元素的溅射和吸收这两个渗金属过程,从放电及溅射等理论角度并结合试验结果进行了分析讨论。结果表明,放电条件对渗层形成效率有很大影响,合金元素的利用率在不同的放电参数下会有悬殊的变化。溅射量决定于溅射电压与气压,利用率则受工件偏压,气压,极间距的共同控制。在一定的溅射量下,利用率的高低决定了渗层质量及形成效率。提高合金元素的利用率是工艺参数造     

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。     

双层辉光离子渗金属主要工艺参数的研究

分析了双层辉光离子渗金属生产过程中的主要工艺参数及其影响。结果表明，源极表面放电功率是影响渗层质量的主要因素。并进行了实验验证。     

Ni—Cr—Mo—Nb合金的阴极溅射行为

研究了双层辉光放电条件下镍基合金Inconel625的阴极溅射行为,结果表明：多组元镍基合金由于各组元溅射率不同,产生择优溅射现象。Mo,Nb等低溅射率元素在阴极表面富集,Ni,Cr等高溅射率元素在阴极表面贫化,使阴极表面发生相变,形成含Mo,Nb奋斗高的金属间化合物析出相P相和Laves相,随着阴极溅射电压的增加,阴极合金元素溅射率增加;并且随着阴极温度升高,阴极溅射率也随之增加。     

In situ and ex situ examination of plasma-assisted nitriding of aluminium alloys

Pre-sputtering and plasma-assisted nitriding of pure aluminium and 2024 aluminium alloy were studied in situ by plasma monitoring and ex situ by several surface analysis methods. The influence of the process parameters, time, temperature, pressure and gas composition on mass and energy distributions of ions, as well as on topography and chemical composition, was examined. The chronology of the sputtering process could thus be clarified. An oxide film which is relatively thick compared to the native oxide layer and enriched with magnesium is formed at the initial stage of the sputtering treatment, followed by the removal of this film with a subsequent roughening of the surface. The cleaning effect of the plasma can be enhanced by increasing the argon pressure or by an intermixture of hydrogen. Due to a supplementary chemical etching, hydrogen admixture reduces the surface roughness and effectively decreases the oxygen content of the surface. During the nitriding treatment, nanocrystalline hexagonal aluminium nitride AlN is formed. Growth rate and nitrogen content of the nitride layer were found to strongly depend on the gas composition during sputtering and nitriding. The positive effect of addition of argon and hydrogen, respectively, arises from an intensification of the nitrogen plasma, the production of nitrogen–hydrogen molecular ions and an increase of the ion energy. The nitrogen pressure affects the layer thickness due to higher nitrogen activity and ion energies. The chemical composition of the cathode material influences discharge current and, as a result, the ion energies.     

Controlling the deposition rate during target erosion in reactive pulsed DC magnetron sputter deposition of alumina

Alumina coatings were synthesized by reactive pulsed DC magnetron sputtering in an industrial-scale deposition system. The aim of this study was to investigate the influence of target erosion (racetrack depth) on the deposition rate. Hysteresis curves, showing the cathode voltage as a function of oxygen flow, were mapped out for different target erosion depths and temperatures, revealing significant variations, e.g. in the metallic mode voltage level. Each deposition was made with a fixed cathode voltage and the cathode current was controlled by adjusting the oxygen flow in a feedback loop by means of which a constant power was maintained. Keeping the power constant, this procedure was repeated for various cathode voltages within the hysteresis transition region and at different racetrack depths and deposition temperatures. The corresponding deposition rates were observed to depend mainly on the relative cathode voltage set-point in-between the oxide and metallic voltage levels in the hysteresis region. This result enables control of the deposition rate by maintaining a constant relative cathode voltage as the target erodes.     

功率对磁控溅射TbDyFe薄膜磁致伸缩性能的影响

采用直流磁控溅射工艺制备TbDyFe磁致伸缩薄膜，通过考察薄膜成分及其微结构，分析研究了溅射功率对薄膜磁致伸缩性能的影响。结果表明，同一薄膜内部成分相当均一，但不同溅射功率条件下的薄膜成分相异。溅射功率较低，薄膜内部微柱状体结构导致了磁各向异性的产生，磁致伸缩性能下降；溅射功率提高到120W，微柱状体结构消失，薄膜内部趋于均一连续，磁致伸缩性能较好。     

Controlled Hollow Cathode Effect: New Possibilities for Heating Low-Pressure Furnaces

The uncontrolled hollow cathode effect may arise in dc plasma surface treatment (nitriding, nitrocarburizing, etc.) of steel parts having small-diameter holes or narrow channels. This may cause nonuniform heating of a part or a batch consisting of parts with markedly different surface/mass ratios. It has been noticed that if the hollow cathode effect is made controllable, it becomes suitable for heating in low-pressure or vacuum furnaces. Additional advantages can be obtained by combining the controlled effect of the hollow cathode with “active screen” plasma treatment due to the removal of the negative influence of the formed arc, of the heating nonuniformity, and of edge effect, as well as by controlling the cathode sputtering. Some experimental results on the topic are presented and the possibilities of application of the effect in industry are outlined.     

网状阴极辉光放电法在钛合金表面渗镀Ta的应用

设计了一种网状阴极溅射靶，它是由多个空心阴极并列交叉组合而成。结构简单，溅射率高。将其用于双层辉光主子渗钽中，在钛合金（Ti-6Al-4V）表面可形成纯Ta沉积层和合金扩散层的复合层组织，进一步提高了钛合金的耐蚀性，是一种高耐蚀合金。     

网状阴极溅射法在钛合金表面渗镀Ta的耐蚀性研究

研究设计了一种网状阴极溅射靶 ,它是由多个空心阴极并列交叉组合而成。结构简单 ,溅射率高。将其用于双层辉光离子渗钽中 ,在钛合金TC4(Ti 6Al 4V)表面可形成纯Ta沉积层和合金扩散层的复合层组织 ,进一步提高了钛合金的耐蚀性 ,是一种高耐蚀合金     

成形金刚石砂轮的电解修整阴极设计

根据电解成形理论设计阴极工具形状，用于金属结合剂成形金刚石砂轮的电解修整。在成形砂轮电解修整电场模型的基础上，应用有限元法求解电场中拉普拉斯方程几何反问题。假定初始阴极形状，施加阳极边界条件，从砂轮阳极表面开始逐层计算电位分布，求得修整间隙区域的等电位线，从而得到修整阴极工具曲线族。论文选择圆形、椭圆形和抛物线形三种典型成形砂轮廓形，设计出它们的修整阴极工具形状，并分析了成形砂轮廓形对修整阴极工具形状的影响。计算结果表明：设计阴极形状的曲率大于成形砂轮轮廓的曲率，且随着x坐标和成形砂轮轮廓曲率的增大，设计阴极与砂轮廓形的偏差增加。论文提供了一种计算机辅助阴极工具设计方法。     

STUDY ON THE TANTALIZING ON THE SURFACE OF TITANIUM ALLOY BY NET-SHAPE CATHODE GLOW DISCHARGING

A new net-shape cathode sputtering target which has a simple structure and a high sputtering was put forward. The multiple-structure made of alloying and coating layers of tantalum was achieved on the surface of TC4 (Ti6AI4V) using this method in double glow surface alloying process. The tantalized samples were investigated by SEM, XRD and electrochemical corrosion method .Results show the complicated tissue of pure tantalizing layer and diffusion layer was successfully formed on the surface of TC4 with the method of net-shape cathode glow discharge, which further improved the corrosion-resistance of TC4 and formed good corrosion-resistant alloys.     

LiFePO4基正极材料容量的温度敏感特性及交流阻抗谱研究

采用原位碳包覆法制备了锂离子二次电池用LiFePO4／C复合正极材料。考察了环境温度对LiFePO4/C电池容量的影响，得到容量与绝对温度之间符合Arrhenius关系。运用交流阻抗谱分析了温度与电池电化学特性的关系，并对电极基于电荷和质量传递控制过程给出了一种新的模拟等效电路，通过Zview拟合软件得到了各个模拟元件的数值及变化趋势，从而定量地解释LiFePO4／C复合电极容量与温度的关系。