激光淬火对钛合金微动磨损性能影响的研究

研究了激光淬火对钛合金微动磨损性能的影响。结果表明：钛合金激光淬火后抗微动磨损能力有所提高,其提高幅度与微动幅度的大小和法向载荷的高低有关,在较大微动幅度或较高法向载荷的条件下,激光淬火可显著地提高钛合金抗微动磨损能力。     

Growth mechanisms of multilayered anodic-titanium-oxide nanotube membranes

Anodic titanium oxide TiO₂ nanotube membranes with one, two and three layers have been prepared by the anodic oxidation method via adjusting applied bias during the oxidation process in glycol electrolytes containing 0.25 wt% or 0.50 wt% NH₄F. The morphologies of the as-prepared samples were presented in detail using scanning and transmission electron microscopy. The results indicated that the glycol electrolyte containing 0.25 wt% NH₄F yielded smooth double-walled nanotubes, and their tubes remained open in multilayers; while the glycol electrolyte containing 0.50 wt% NH₄F yielded single-wall nanotubes with ripples, and most of the nanotubes have closed bottoms. In the case of nanotubes with closed bottoms, it was proposed that the newly grown nanotubes on the succeeding layer formed in the gap between the nanotubes of the previous layer. In order to keep track of the growth of the nanotubes, samples were anodized for different periods of time from 1 to 90 min to study their formation process. Growth mechanisms were proposed for different morphologies.     

钛合金缺陷相控阵超声衍射波定量方法

针对传统衍射波设置法受散射杂波干扰难以进行钛合金缺陷定量的问题,分析了体积型缺陷和面积型缺陷的超声衍射波信号特点,并通过试验测试了钛合金材料的衍射波信号特征,提出了基于相控阵超声的高信噪比衍射波定量方案。制备了不同尺寸的长横孔试块和通槽试块,分别模拟体积型缺陷和面积型缺陷,测试试验定量。结果表明,采用相控阵超声衍射波定量方法对两种类型缺陷的定量精度均达到了1 mm以内。相控阵超声衍射波定量法操作简单,可为钛合金缺陷定量提供新的思路。     

Ti(C0.3N0.7)-Si3N4复合材料的制备与性能

在Si3N4基体材料中添加高弹性模量的第二相粒子Ti(C0.3N0.7),研究第二相的引入对氮化硅陶瓷材料力学性能的影响.结果表明,在Si3N4基体材料中添加Ti(C0.3N0.7)能起到弥散颗粒增韧的作用.     

镁热法生产海绵钛还原过程反应熔池的传热模型

利用VOF多相流模型、能量方程、RNGk-ε方程及其边界条件,建立镁热法生产海绵钛还原熔池的传热模型。结果表明,计算得到的温度场分布与实测值吻合较好。     

High-temperature oxidation of titanium carbide in oxygen

The kinetics of titanium carbide oxidation in oxygen over the temperature range of 600–1200°C and oxygen pressure from 0.1 to 740 Torr have been studied with a vacuum microbalance. Layer-by-layer x-ray analysis, petrography, metallography, and gas chromatography have been used to analyze the oxidation products. A paralinear nature of the oxidation of material was established, and the rate constants of the process were calculated for the corresponding parabolic and linear portions of the kinetic curves. It was shown that a gaseous product, CO₂, formed, as well as a solid product, TiO₂ (rutile), both stoichiometric and nonstoichiometric. The lower oxides, Ti₃O₅, Ti₂O₃, TiO, were noted in the scale at temperatures from 700 to 800° and low oxygen pressures, their relative quantity rising with decreasing pressure. Based on x-ray analysis and microhardness measurements, it was concluded that titanium oxicarbides formed in the TiC, directly adjacent to the scale. A possible oxidation mechanism of titanium carbide is proposed.     

农业覆盖用非织造布的保温性能

采用十二烷基苯磺酸钠对TiO2进行改性,通过正交试验研究改性剂用量、温度、时间和PH值对TiO2表面改性的影响。结果表明,当十二烷基苯磺酸钠用量为11%, 温度为90℃,时间为45min,PH值为5时,TiO2改性效果最好。将改性TiO2涂覆的无纺布用于覆盖茶树,记录无纺布棚内外温差,作棚内茶叶中茶多酚和咖啡因含量色谱图,研究农用覆盖无纺布的保温性能。结果发现当改性TiO2质量比为25%时,农用覆盖无纺布棚内外温差最大,茶多酚和咖啡因含量最高,农用覆盖无纺布保温性能最佳。     

无机盐对TiO2催化降解活性染料的影响

制备了可见光响应型纳米TiO2光催化剂,研究在无机盐存在下,TiO2对均三嗪型活性染料的光催化降解机制。结果表明,氯化钠对TiO2光催化降解活性染料既有促进作用又有抑制作用,其取决于氯化钠的浓度;硫酸钠对TiO2的光催化性能只有抑制作用,且随硫酸钠浓度的增大而增加;无机盐对X型活性染料活性艳蓝X-BR的光催化脱色没有影响,但适量的无机盐能促进K型活性艳蓝K-GR的降解。不同pH值条件下,无机盐对活性染料光催化脱色的影响不同,在酸性条件下无影响,中性和碱性条件下影响较明显,脱色率由大到小依次为:酸性>碱性>中性。     

真丝织物的钛氟溶胶抗紫外拒水整理

采用溶胶-凝胶法制备一种以钛酸四丁酯(TTB)为主要原料的钛纳米溶胶,以及一种以十二氟庚基丙基三甲氧基硅烷(FAS)为主要原料的氟纳米溶胶。以传统轧烘焙工艺首先在真丝织物上形成钛纳米凝胶薄膜,再浸轧氟纳米溶胶进行轧烘焙处理。试验表明,整理后的真丝UPF值由原布31.99增至136.54,50次水洗后为96.51,仍保持了较好的抗紫外性能;织物的接触角为137.6°,20次水洗后保持在102.5°,具有良好的拒水性能;但是,整理后的真丝织物断裂强力有所下降,而纬向撕破强力和抗弯长度则有所提高。     

Self-cleaning wool: effect of noble metals and silica on visible-light-induced functionalities of nano TiO2 colloid

This study intends to enhance the functionality of titanium dioxide (TiO₂) nanoparticles applied to wool fabrics under visible light. Herein, TiO₂, TiO₂/SiO₂, TiO₂/Metal, and TiO₂/Metal/SiO₂ nanocomposite sols were synthesized and applied to wool fabrics through a low-temperature sol–gel method. The impacts of three types of noble metals, namely gold (Au), platinum (Pt), and silver (Ag), on the photoefficiency of TiO₂ and TiO₂/SiO₂ under visible light were studied. Different molar ratios of Metal toTiO₂ (0.01, 0.1, 0.5, and 1%) were employed in synthesizing the sols. Photocatalytic efficiency of fabrics was analyzed through monitoring the removal of red wine stain and degradation of methylene blue under simulated sunlight and visible light, respectively. Also, the antimicrobial activity against Escherichia coli (E. coli) bacterium and the mechanical properties of fabrics were investigated. Through applying binary and ternary nanocomposite sols to fabrics, an enhanced visible-light-induced self-cleaning property was imparted to wool fabrics. It was concluded that the presence of silica and optimized amount of noble metals had a synergistic impact on boosting the photocatalytic and antimicrobial activities of coated samples. The fabrics were further characterized using attenuated total reflectance, energy-dispersive X-ray spectrometry, and scanning electron microscopy images.