固态还原法处理钛铁矿

以钛铁矿为原料，经预氧化处理－碳或氢气还原－稀盐酸浸取除铁过程得到含ＴｉＯ２９５％以上的人造金红石，结果表明，最佳的氧化条件为８００℃，１小时，用碳作还原剂时，还原条件为１０００℃，５小时，矿、碳、助熔剂质量为１：０．１５：０．５，加入助熔剂ＮａＣｌ可降低反应温度而利于反应的进行。     

基片负偏压对PEMSIP法TiN涂层的影响

应用Ｘ射线衍射分析研究了基片负偏压对ＰＥＭＳＩＰ法ＴｉＮ涂层相组成的影响；结果表明，随着基片负偏压增加，膜层相组成朝着富氮相及其含量增加的方向发展，进而影响膜层的硬度。通过微区化学成分分析（ＥＤＳ）研究了膜基界面附近的成分分布。结果表明，界面处有过渡层；偏压愈高，过渡层愈显著。     

2─（5─溴─2─毗啶偶氮）─5─二乙氨基酚树脂相分光光度法测定铁矿中痕量钛

离子交换树脂可吸附金属有色配合物，通过直接测定已经吸附了金属有色配合物的树脂相的吸光度，不需预浓缩或分离，可检测样品溶液中痕量金属离子的含量。研究了Ｔｉ（Ⅳ）─Ｈ＿２Ｏ＿２─５─Ｂｒ─ＰＡＤＡＰ（２─（５─溴─２─毗啶偶氮）─５─二乙氨基酚）形成的三元异配合物定量吸附于树脂上的实验条件，在ｐＨ３．０～５．０的酸性介质中，加入草酸钠掩蔽铁（Ⅲ）后，在过氧化氢存在下，使Ｔｉ（Ⅳ）与５─Ｂｒ─ＰＡＤＡＰ显色并与树脂混合搅拌１５ｍｉｎ，吸附达平衡，树脂相配合物的最大吸收波长位于６２０ｎｍ；表现摩尔吸光系数为３．６５×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）；钛含量在０～５μｇ／２５ｍｌ范围内符合比耳定律；测定铁矿中的痕量钛，相对标准偏差为１．４％；回收率为９９％～１０１％。     

端铣速度对钛合金TB6表面完整性的影响

钛合金TB6铣削表面完整性对其使用性能具有重要影响,试验研究了端铣速度对表面完整性的影响规律。研究表明:在20~60m/min范围内的低速铣削时,表面粗糙度随铣削速度增大先减小而后增大,表面显微硬度值随铣削速度增大而增大,残余应力数值随速度增大而减小;在100~300m/min范围内的高速铣削时,表面粗糙度随铣削速度增大而减小,表面显微硬度随着铣削速度增大而变小,表面残余应力数值随速度增大而减小,残余应力沿深度方向分布大致呈"勺"型,高速铣削表面观察到了熔滴缺陷。     

BST薄膜的制备工艺与太赫兹介电特性测试

经过多组对比实验,通过XRD、AFM、SEM等表征手段优化了BST薄膜的制备工艺。结合BST基薄膜器件的电极制备、微结构加工制备了太赫兹频段电可调的频率选择表面。通过太赫兹测试系统验证了在太赫兹频段BST薄膜的可调性,在电场作用下通带频率可以从0.85THz调节到0.87THz,结合仿真研究给出了确定铁电薄膜在THz频段介电参数的方法。相关研究可用于精确测定铁电薄膜在THz频段的介电特性,为铁电薄膜功能器件的研制提供精确的介电参数测试方法。     

超载试验中TC18钛合金低周疲劳特性与断口分析

为了研究超载试验对TC18钛合金低周疲劳特性的影响,常温下,本文在恒幅低周疲劳和间隔超载载荷两种工况下,对两种厚度的β锻TC18钛合金中心开孔试样进行了研究,对其低周疲劳性能及断口形貌开展了深入探索。同时,在应力比和恒幅载荷相同的情况下,与无超载情况下的裂纹扩展速率进行了对比分析。疲劳试验结果表明：β锻TC18钛合金存在明显的超载迟滞效应;每100次恒幅载荷间隔2次1.3倍超载载荷时,低周疲劳寿命约为恒幅低周疲劳寿命的2倍。     

Microstructure and properties of an Al-Ti-Cu-Si brazing alloy for SiC-metal joining

An Al-Ti-Cu-Si solid-liquid dual-phase alloy that exhibits good wettability and appropriate interfacial reaction with SiC at 500-600℃ was designed for SiC-metal joining. The microstructure, phases, differential thermal curves, and high-temperature wetting behavior of the alloy were analyzed using scanning electron microscopy, X-ray diffraction analysis, differential scanning calorimetry, and the sessile drop method. The experimental results show that the 76.5Al-8.5Ti-5Cu-10Si alloy is mainly composed of Al-Al₂Cu and Al-Si hypoeutectic low-melting-point microstructures (493-586℃) and the high-melting-point intermetallic compound AlTiSi (840℃). The contact angle, determined by high-temperature wetting experiments, is approximately 54°. Furthermore, the wetting interface is smooth and contains no obvious defects. Metallurgical bonding at the interface is attributable to the reaction between Al and Si in the alloy and ceramic, respectively. The formation of the brittle Al₄C₃ phase at the interface is suppressed by the addition of 10wt% Si to the alloy.     

Characterization of Cu-Ti powder metallurgical materials

Powder metallurgical Cu-Ti alloys with different titanium additions produced by hot pressing were characterized by optical microscopy, scanning electron microscopy, X-ray diffraction analysis, and hardness, wear and bending tests. The addition of titanium to copper caused the formation of different intermetallic layers around titanium particles. The titanium content of the intermetallics decreased from the center of the particle to the copper matrix. The hardness, wear resistance, and bending strength of the materials increased with increasing Ti content, whereas strain in the bending test decreased. Worn surface analyses showed that different wear mechanisms were active during the wear test of specimens with different chemical compositions. Changes in the properties of the materials with titanium addition were explained by the high hardness of different Cu-Ti intermetallic phases.     

硫酸钛水解制备TiO2纳米粒子载荷添加剂

以硫酸钛为前驱体 ,采用溶胶凝胶超临界干燥法制备TiO2 纳米粒子润滑油载荷添加剂。采用红外光谱、BET氮容量吸附、透射电镜、热重差热分析、X 射线衍射等手段对TiO2 纳米粒子的特性进行了表征 ,分析了制备过程中的各种影响因素。结果表明 ,采用强烈搅拌、匀速滴加絮凝剂、控制反应终点的 pH值以及用乙醇为介质进行超临界干燥的方法制备出的TiO2 纳米粒子的平均粒径为 15～ 2 0nm ,比表面积约为 10 0m2 /g ,其结构为锐态型 ,表面有微量水和乙醇吸附。     

液相水解法制备纳米二氧化钛

用液相水解法制备了纳米二氧化钛,并对各种影响因素进行了讨论.制得的二氧化钛粒径为20～30nm.