高温过热器12Cr2MoWVTib（102）钢管的显微组织和相结构分析

本文对原始状态和在火力发电厂使用不同时间的高这热器１０２钢管进行了显微组织和相结构变化规律的探讨和研究。显微组织研究表明，１０２钢管在高温高压下长期运行过程中，使用温度对显微组织和碳化物相有明显影响，而使用时间对其影响不如温度影响强烈。碳化物颗粒图象分析表明，碳化物随着使用时间缓慢长大，而新的碳化物不沉淀，使颗粒总数不断增加，颗粒，间距逐渐缩小。Ｘ射线衍射数据证明，钢管在高温长期使用过程中，ＭＣ相     

相转移法制备高纯超细TiO2技术研究

报道了用相转移法制备高纯超细ＴｉＯ２的新技术；探讨了Ｔｉ（Ⅳ）从有机相转移到水相发生水解反应的机理 ；通过ＴＧ－ＤＴＡ分析以及ＸＲＤ物相分析对水解产物的组成、热分解机理，晶型转变规律进行了研究，建立了水解产物焙烧的最佳温度。     

An investigation of pore cracking in titanium welds

Two welded Ti-6A1-4V pressure vessels leaked prematurely in service. The leaks were caused by cracks emanating from weld porosity. The cracks originated during fabrication, with subsequent growth in service leading to the formation of the leak paths. Pore cracking is thought to be caused by a mechanism that involves both sustained-load and cyclic contributions, with the former being the more prominent. It is shown that the tendency for cracking is influenced by pore position and that pore size is not a deciding factor in that regard. The factors that govern pore cracking are discussed, and the possible role of interstitial embrittlement is assessed.     

Superplastic behaviour of Ti-48at.%Al two-phase titanium aluminide compacts made from mechanically alloyed powder

An HIP compact of MA-processed powder having a nominal composition of Ti-48at.% Al was produced. The compact consisted of a large amount of TiAl(λ) and a small amount of Ti₃Al (₂), in a completely ultra-fine equiaxed grain structure. This two-phase compact showed typical superplastic deformation behaviour. A maximum elongation of 550% was obtained. A strain exponent, n = 2, and grain size exponent, p = 2, were determined from the results of a strain-rate-change test and a creep test at constant initial stress using samples having various grain sizes, respectively. The activation energy for creep, Q_c at constant stress was calculated to be 350 kJ/mole. It is concluded that the superplastic deformation mechanism of the material under study is grain boundary sliding controlled by lattice diffusion in the TiAl phase.     

钛对耐硫变换催化剂性能的影响

利用常压微反色谱、程序升温还原（ＴＰＲ）等技术研究了钛对耐硫变换催化剂性能的影响，结果表明：（１）钛能明显提高耐硫变换催化剂的活性，尤其是在低于６２３Ｋ时活性提高最为明显；（２）工业侧流试验后，含钛样品的保留活性及活性保留率均高于Ｋ８－１１；（３）催化剂中添加助剂ＴｉＯ２后，能显著提高对原料气中Ｈ２Ｓ含量变化的适应能力，因此可以拓宽对原料气的选择范围，对工业生产有着十分重要的现实意义。     

Formation of titanium and cobalt germanides on Si (100) using rapid thermal processing

Titanium and cobalt germanides have been formed on Si (100) substrates using rapid thermal processing. Germanium was deposited by rapid thermal chemical vapor deposition prior to metal evaporation. Solid phase reactions were then performed using rapid thermal annealing in either Ar or N₂ ambients. Germanide formation has been found to occur in a manner similar to the formation of corresponding silicides. The sheet resistance was found to be dependent on annealing ambient (Ar or N₂) for titanium germanide formation, but not for cobalt germanide formation. The resistivities of titanium and cobalt germanides were found to be 20 μΩ-cm and 35.3μΩ-cm, corresponding to TiGe₂ and Co₂Ge, respectively. During solid phase reactions of Ti with Ge, we have found that the Ti₆Ge₅ phase forms prior to TiGe₂. The TiGe₂ phase was found to form approximately at 800° C. Cobalt germanide formation was found to occur at relatively low temperatures (425° C); however, the stability of the material is poor at elevated temperatures.     

Microstructure of Silicon Carbide Whiskers Synthesized by Carbothermal Reduction of Silicon Nitride

The microstructure of silicon carbide whiskers synthesized by carbothermal reduction of silicon nitride has been studied using transmission electron microscopy. All of the whiskers examined are single crystals, and grow in the (111) crystallographic direction. Two different forms of stacking faults and microtwins were observed; in one the planar defects are normal to the whisker growth direction, and the other has the defect planes at an angle of about 70° to the growth axis, while both forms of the defects are on the [111] closed-packed planes. Without the addition of catalyst, droplets containing metallic impurities were not found at the tips of the whiskers synthesized by the present process. A core and outer regions were observed in the single-crystal whiskers, which may be evidence that the whiskers were formed by a two-stage mechanism.     

湘潭新大粉末冶金设备制造有限公司的一体化真空烧结炉

简要介绍了湘潭新大粉末冶金设备制造有限公司研制的一体化真空烧结炉的炉子结构、脱蜡系统、工艺气体的引入系统、设备的控制系统以及炉子性能的鉴定结果。     

高速线材轧制用硬质合金轧辊的质量控制

通过对高速线材轧制用硬质合金轧辊 (轧槽 )失效机理的分析 ,提出了高速线材轧制用硬质合金轧辊质量控制的基本方法 ,认为轧辊质量控制的关键在于轧辊材料设计、生产工艺过程控制、轧制过程、轧机工况、轧辊储运装卸以及轧制环境因素的控制 ,并建议尽早制订相关的材料和产品质量标准。     

TiO_2纤维的制备、表征及其光催化活性

采用常压乙二醇法制备出在可见光下具有较高催化活性的TiO2纤维。扫描电子显微镜表征结果表明,TiO2纤维直径为0.8～2.0μm、长度为5～25μm;BET比表面积和X射线衍射表征结果表明,随焙烧温度的升高,比表面积减小,TiO2纤维晶型逐渐由锐钛矿型向金红石型转变;紫外-可见漫反射光谱分析结果表明,TiO2纤维在可见光区有明显的吸收。在可见光下对甲基橙和苯酚的降解实验表明,焙烧温度为400℃时TiO2纤维的催化活性最好,对甲基橙和苯酚的降解率分别达到90.3%和84.0%;所制备的TiO2纤维比溶胶-凝胶法制备的锐钛矿型TiO2在可见光下具有更好的催化活性,原因是其能带间隙减小和吸收波长扩展到可见光区所致。