钛及钛合金材料的焊接技术

通过对钛及钛合金材料特点及焊接性的分析研究,并针对钛及钛合金焊接中易产生氧化、裂纹、气孔等焊接缺陷,使我们掌握钛及钛合金材料的焊接技术要求,并通过制定合理的焊接工艺,获得我们满意的焊接质量。     

浅谈钛合金焊接

钛合金材料不但具有比强度大、韧性及焊接性能好等优点，同时还有着优良的耐腐蚀性。但是由于钛材的化学性质比较活泼，因此在实施钛合金焊接时严格控制焊接工艺显得尤为重要。本论文通过对钛合金特点及焊接性的分析研究，以TA10钛合金为例，针对钛合金焊接中易产生氧化、裂纹、气孔等焊接缺陷，制定合理的焊接工艺，获得我们满意的焊接质量。     

钛及钛合金复合材料发展及工业应用

钛及钛合金具有重量轻、强度大、耐热性强、耐腐蚀、生物兼容性好等优良特性,是优质新型材料和功能材料.爆炸焊接钛及钛合金复合钢板不仅大大节约钛资源而且提高了材料使用工况,增加了设备的使用寿命.本文主要研究爆炸焊接钛及钛合金复合材料性能特点、发展及工业应用现状,并提出我国爆炸焊接钛及钛合金复合材料研究发展中尚存在的问题.     

浅论钛管道焊接

探讨钛材在加工、焊接等热过程中材料的变化机理,提出防止污染是影响焊接质量的关键;分析钛材管道焊接产生的冷裂纹、气孔、氧化等缺陷的原因和形成机理,提出焊接工艺措施,以确保焊接的质量。     

钛合金焊接工艺的探讨

分析了钛合金屏蔽电泵试制中钛材部件焊接出现的缺陷。通过焊接工艺试验 ,提出了制定焊接工艺应注意的若干问题。     

钛的氩弧焊焊接

近年来，钛在石油化工、海洋工程、电子元器件生产厂家的耐腐蚀设备和管道中得到了越来越广泛的应用。本文从钛的性质入手，对采用氩弧焊接钛时的焊接性进行了详细的分析，认为高温下吸收气体引起的接头脆化、冷裂纹、气孔是焊接钛时的主要问题，同时分析了在焊接钛衬里压力容器时，接变形对其使用性能的影响，并对产生这些问题的原因和影响因素进行了分析，提出了防止和减少上述问题发生的措施。对氩弧接钛的焊接工艺、工艺装备、焊接规范、焊接检验作了详细的介绍。本文介绍的氩弧焊焊接钛的方法和工艺也适用于钛合金的焊接。     

离子膜单元槽修复中的焊接

在分析复极式离子膜单元槽修复过程中阳极钛板或阴极镍板出现焊接裂纹和气孔等焊接缺陷的产生机理的基础上，得到了获得合格焊接质量的焊接工艺和焊接方法。     

钛及钛合金异形封头的制造

随着国内装备制造业的发展,钛及钛合金容器的使用越来越广泛。作为容器的关键组成部分,钛及钛合金封头的压制对封头制造厂家来说,已经呈现常态化的形式,但在压制过程中极易出现的点状、线状缺陷,需要从模具和加热方面进行改进。     

钛管焊接工艺探讨

通过对钛材焊接性的分析 ,从钛管焊接保护、焊前处理、工艺规范等方面入手解决钛材的低温氧化和气孔问题。在施工过程中所有的焊缝色为保护最佳的银白色 ,射线探伤一次合格率达 98 0 7%     

钛设备在环丙装置中的应用

论述了钛及钛合金设备在环丙装置中的应用现状，分析了钛及钛合金材料在环丙装置中的耐腐蚀性能、机械性能及经济效果对比，并针对部份钛设备存在的失效现象和缺陷提出了改进措施。     

纯Ti2O3中Ti3+含量的测定

使用容量法和重量法，测定了ＴｉＯ２还原产物中的Ｔｉ２Ｏ３含量。随着Ｔｉ２Ｏ３含量的增高，方法的准确性也提高。两种方法都具有很好的精密度。     

Comparison of corrosion behavior of Ti3SiC2 and Ti3AlC2 in NaCl solutions with Ti

Corrosion behavior of self-sintered, ternary-layered titanium silicon carbide (Ti₃SiC₂) and titanium aluminum carbide (Ti₃AlC₂) fabricated by an in-situ solid-liquid reaction/hot pressing process was investigated by potentiodynamic polarization, potentiostatic polarization and electrochemical impedance spectroscopy in a 3.5% NaCl solution. Commercially pure titanium (Ti) was selected for comparison through XRD, XPS, SEM and EDS examinations for elucidating both the passivation behavior and corrosion mechanism of the alloys. Both Ti₃SiC₂ and Ti₃AlC₂ exhibited significantly superior passivation characteristics compared to Ti; Ti₃SiC₂ also showed better corrosion resistance. The silicon/aluminum site is prone to attack, and the difference in the diffusion rate between the A-site atoms and titanium decreases the passivation ability of the MAX phase. CP titanium exhibited a lower passivation current density and did not undergo breakdown in the test potential region while two MAX phases are destroyed. Nevertheless, the corrosion resistances of Ti₃SiC₂ and Ti₃AlC₂ are comparable to that of CP titanium.     

钛铁试剂分光光度法连续测定陶瓷材料中的铁和钛

研究了钛，铁与钛铁试剂的显色反应。该分析方法的最大优点是可在同一溶液中用光度法连续测定样品中的钛和铁含量。配合物最大吸收波长分期为410nm和565nm，二氧化钛含量在0－200μg/50ml，三氧化二钛含量在0－300μg/50ml范围内符合比尔定律。方法用于测定硅酸盐样品中钛和铁，结果满意。     

Ru-Ti-Sn/Ti三元氧化物金属阳极的析氧性能

本文用一般电极性能测试方法考察了Ru-Ti-Sn/Ti三元氧化物涂层阳极的电极寿命和析氧活性。实验表明，与Ru-Ti/Ti、Ru-Ti-Ir/Ti氧化物阳极比较，Ru-Sn-Ti/Ti阳极具有一定的析氧活性和抗氧化作用。     

Oxidation and creep behavior of textured Ti2AlC and Ti3AlC2

The oxidation and creep behaviors of textured Ti₂AlC and Ti₃AlC₂ ceramics were characterized. The oxidation behavior of the two materials, which was studied in air at temperatures ranging from1000 to 1300 °C, was observed to be anisotropic and the materials exhibited a better oxidation resistance along a direction transverse to the c-axis. The correlation between the overall parabolic rate constant and oxidation temperature of both textured materials was characterized, providing new insights into the oxidation kinetics. The results indicate that the texturing has a negligible influence on the creep behavior in the assessed temperature range of 1000?1200 °C in air, for the applied stresses ranging from 40 to 80 MPa. In this stress regime, the creep behavior of textured Ti₂AlC and Ti₃AlC₂ appears to be controlled by grain boundary sliding. This behavior can be rationalized based on a model for superplastic deformation, indicating pure-shear motion under stationary conditions accommodated by lattice or grain-boundary diffusion.     

原位热压TiC/Ti/Al合成Ti2AlC的研究

本以TiC／Ti／Al为原料，采用热压T艺在1400℃原位合成和烧结含少量第二相Ti3AlC2的Ti2AlC材料。通过不同温度和不同热压时间下合成试样的XRD分析探讨了Ti2AlC的合成过程。结果表明，高温下Ti与Al反应生成中间相TiAl金属间化合物，然后TiC与TiAl金属间化合物反应生成Ti2AlC。不同温度下合成的Ti2AlC颗粒具有不同的形貌特征。     

Electrochemical decomposition of bisphenol A using Pt/Ti and SnO2/Ti anodes

Methodology for the electrochemical decomposition of bisphenol A is described. The electrochemical behaviour of bisphenol A at a Pt electrode was investigated by means of cyclic voltammetric techniques. The electrochemical oxidation of bisphenol A led to the deactivation of the electrode as a result of the deposition of an electropolymerized film. However the electrochemical decomposition of bisphenol A could be achieved by the use of a platinum coated titanium (Pt/Ti) electrode and a tin dioxide coated (SnO₂/Ti) electrode. The electrolysis was carried out galvanostatically at a constant current of 0.3 A. The mineralization of bisphenol A was monitored by determining the amount of total organic carbon. Furthermore, the generation and nature of intermediates produced in the electrochemical reactions was investigated. Although large amounts of aliphatic acids were generated by electrolysis with the Pt/Ti anode, they were produced only to a small extent in at the SnO₂/Ti anode. In the case of the SnO₂/Ti anode, bisphenol A is rapidly oxidized to carbon dioxide and water, compared to the Pt/Ti anode.     

Molten salt synthesis and formation mechanism of Ti3AlC2: A new path from Ti2AlC to Ti3AlC2

Fine, pure Ti₃AlC₂ powder is prepared in a very mild condition via Ti₃Al alloy and carbon black with the assistance of molten salts. X-ray diffraction, scanning electron microscopy, TG-DSC, and transmission electron microscopy (TEM) characterizations show that the high purity, nanosized Ti₃AlC₂ can be obtained at 900°C with the 1:1 salt-to-material ratio. The formation mechanism of Ti₃AlC₂ through this strategy of alloy raw material is fully studied under further TEM investigations, showing that the reaction process can basically be described as Ti₃Al and C → TiAl and TiC → Ti₂AlC and TiC → ψ and TiC → Ti₅Al₂C₃ and TiC → Ti₃AlC₂, where the key ψ, a modulated Ti₂AlC structure, is determined for the first time containing alternate-displacement Al layers along (0 0 0 2) of Ti₂AlC phase with a distinct selected area electron diffraction pattern. Such alternant displacement is considered a precondition of forming Ti₅Al₂C₃ through topotactic transition, followed by Ti₅Al₂C₃ converting into Ti₃AlC₂ by the diffusion of Ti, C atoms in the outside TiC. Several parallel orientations can be observed through the phase transition process: Ti₂AlC (0 0 0 2)//ψ (0 0 0 1), ψ (0 0 0 1)//Ti₅Al₂C₃ (0 0 0 3), Ti₅Al₂C₃ (0 0 0 3)//Ti₃AlC₂ (0 0 0 2). Such parallel orientations among these phases apply an ideal condition for the topotactic reaction. The distinct path of the phase transition brings a significant change of heat effect compared with the traditional method, leading to a fast reaction rate and a mild reaction condition.     

Ti33 Ru33 Co33尖晶石型钛阳极的制备

采用溶胶－凝胶法制备了Ｔｉ３３Ｒｕ３３Ｃｏ３３尖晶石型钛阳极，并对涂层运用ＤＴＡ，ＸＲＤ，ＴＥＭ，ＳＥＭ等手段进行了测试，研究结果表明：涂层为尖晶石结构，形貌呈块状；钛阳极涂层烧结温度为３２０℃，涂层晶粒小于１０ｎｍ。     

Synthesis of Solid Phosphate Compounds of Ti(III) and Ti(IV)

Several new methods for the synthesis of TiPO₄ are described. Crystalline phosphate compounds containing boron and titanium in a single III or mixed (III, IV) oxidation states have been synthesized and identified by X-ray diffraction. An additional family of phosphate compounds containing only Ti(III, IV) has also been synthesized and identified. All the compounds exhibit attractive colors, e.g., bright green, blue, purple, and black, and are stable at room temperature in air and in boiling water.