O.I.Shpigunova
,
S. V. Shpigunov
,
Yu.N. Saraev (Institute of Strength Physics and Materials Science
,
Siberian Branch
,
Russian Academy of Sciences
,
Tom- sk
,
Russia)
金属学报(英文版)
In this paper the processes of melting and transfer of an electrode metal to the molten pool, hydrody- namics of molten pool in controlled pulsed arc welding in carbon dioxide have been investigated.The process of pulsed arc welding with systematic short - circuits of the arc gap is realized by adaptive algo- rithms of pulsed control over main energetic parameters of welding - arc current and voltage,arc heated efficiency,peak,short - circuiting current, which provide the dosage of energy for energy for melting and transfer of every for of an electrode metal, the control over fluidity of the weld pool. Physica and mathematical models describing such processes in CO2, origind software hare been developed.The re- sults of physical simulation and mathemaical modelling permit to determine the influence of energetic parameters of the process on the condition of the "power source-electrode-arc-molten pool" electrodynamic system at each moment of time.
关键词:
pulse
,
null
,
null
,
null
Acta Chimica Sinica
Passive film formed on 304 stainless steel in 2.5 mol/L H2SO4 solution by using alternating voltage (A. V.) passivation have been investigated by measuring capacitance and photoelectrochemical parameters. The investigation of the effect of measure frequency on the slope of Mott-Schottky curve has been carried out. The photoelectrochemical measurements were consistent with the capacitance measurement. Analysis of the experimental results showed that the passive film formed 304 stainless steel by using A. V. passivation exhibits semiconducting properties. Using the simple model of semiconductor rather than the multi-donor level model can explain satisfactorily the semiconducting behavior of the film formed on 304 stainless steel by using A.V. passivation.
关键词:
A. V. passivation;passive film;semiconducting properties;stainless;steel;model;electrodes
马保国
,
柯凯
,
李相国
,
王晓亮
硅酸盐通报
研究了V、Cr对β-C2S形成过程的影响,在生料中分别掺入质量分数0.5%、1.0%、1.5%、2.0%的V2O5、Cr2O3,煅烧至1400 ℃,利用化学分析、XRD、SEM-EDS、高温显微分析等方法,探讨V5+、Cr3+的掺杂影响机理.结果表明:V2O5、Cr2O3均易稳定β-C2S存在,当其掺量分别大于1.0%、1.5%时,对生料易烧性及熟料矿物相的形成均有不利的影响;因V5+与 Al3+离子半径相近,可取代Al3+反应稳定MeO5-4,导致液相粘度增大,而Cr3+与 Fe3+离子半径相近,其对液相作用机理相反;V5+较Cr3+更易固溶在熟料矿物相中,故Cr2O3掺杂影响规律变化相对V2O5在掺量上存在一定的滞后性.
关键词:
β-C2S
,
液相粘度
,
易烧性
,
固溶
徐永礼
,
庞祖高
,
马宽猷
,
韦曼云
,
黄银燕
表面技术
利用扫描电镜、X射线衍射分析技术,对比经过RE-N-C-S-V-Nb多元共渗处理、气体渗氮处理和淬火+回火处理的H13钢三种试样的热疲劳性能,依据裂纹特征、裂纹结构,证明RE-N-C-S-V-Nb多元共渗H13钢具有较强的抗热疲劳性能.研究了多元共渗钒铌碳氮化物的细晶强化作用和位错强化作用,及其对钢热稳定性、高温硬度和抗氧化性的影响,从理论上揭示了RE-N-C-S-V-Nb多元共渗对热疲劳性能的强化机制.
关键词:
H13钢
,
多元共渗
,
热疲劳性
,
热稳定性
,
抗氧化性
Journal of Applied Electrochemistry
Surface films of TiN and TiN/Ti were deposited on Ti6Al4V alloy by arc ion plating (AIP). Open-circuit potential, potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS) were employed to investigate the corrosion performance of TiN and TiN/Ti films in Hank's simulated body fluid at 37 A degrees C and pH 7.4. Scanning electron microscopy (SEM) was used to study the surface morphology of the corroded samples after the potentiodynamic polarization tests. The results show that the TiN and the TiN/Ti films can provide effective protection for the Ti6Al4V substrate in Hank's fluid, and the TiN/Ti composite film showed a corrosion resistance superior to that of the TiN film. The outer TiN layer of the composite film mainly acted as an efficient barrier to corrosion during short-term experiments. In contrast to the bare Ti6Al4V, no pitting was observed on the surface of the TiN and TiN/Ti films deposited on the bare alloy after potentiodynamic polarization.
关键词:
Corrosion;Arc ion plating;TiN film;TiN/Ti composite film;Ti6Al4V;coatings;biocompatibility;resistance;titanium
冷崇燕
,
周荣
,
张旭
稀有金属材料与工程
采用注入不同剂量5×1016,1×1017,5×1017和9×1017ions/cm2,加速电压30kV对Ti6Al4V合金进行Ag离子注入表面改性.使用动电位极化曲线研究Ag离子注入前后Ti6Al4V合金抗Hank's溶液腐蚀性能,利用小角掠射X射线衍射技术研究Ag离子注入前后Ti6Al4V合金表面物相组成,用X射线光电子能谱技术分析离子注入合金表面和腐蚀样品表面元素存在的化合态.结果表明,Ag离子注入提高了合金抗Hank's溶液腐蚀性能,腐蚀电流密度随Ag离子注入剂量的增加稍有变化.离子注入Ti6Al4V合金表面的氧化物腐蚀阻挡层、离子注入表面合金层和表面生成的Ag和TiAg有利于合金抗Hank's溶液腐蚀性能的改善.
关键词:
Ti6Al4V
,
Ag离子注入
,
抗腐蚀性能
杨慧
,
梁成浩
,
黄乃宝
材料科学与工艺
为探索碳离子注入Ti-6A1-4V合金在人工模拟体液Hank’s溶液中的性能，采用电化学方法、扫描电子显微镜和X射线衍射对其缝隙试样在人工模拟体液Hank’s溶液中的电化学行为进行了研究，结果表明：碳离子注入后，Ti-6A1-4V合金缝隙试样的腐蚀电位升高、电荷转移电阻增大，阳极极极化电流密度降低，改善了电化学性能；碳离子注入后，Ti-6A1-4V合金表面形成主要由TiC组成的无序层膜，该膜层阻滞了合金元素的溶解，提高了合金的耐缝隙腐蚀性能。
关键词:
碳离子注入
,
Ti-6A1-4V合金
,
Hank’s人工模拟体液
,
缝隙腐蚀行为
