模糊控制在烧结配料自动化控制中的应用

介绍了模糊控制在烧结配料自动化控制中的应用。介绍了系统构成、控制规律,并通过实际应用验证了采用模糊控制后的控制效果,保证物料配比量的准确和稳定,并阻止了下料故障,提高了烧结矿的质量。     

液相烧结对Ba(Ti0.91Zr0.09)O3陶瓷介电性能的影响

采用固相反应法制备了添加1wt%CuO-BaO混合物的Ba(Ti0.91Zr0.09)O3铁电陶瓷,借助XRD、SEM、Agilent4284测试仪,讨论了加入CuO-BaO混合物对Ba(Ti0.91Zr0.09)O3铁电陶瓷的烧结温度、相结构、显微组织及介电性能的影响.结果表明:添加1wt%CuO-BaO混合物,能有效降低Ba(Ti0.91Zr0.09)O3的烧结温度,室温介电常数高,介电损耗小.在1MHZ下εTl=3 150,tgδ=0.06,并且伴有介电弛豫现象.     

Agglomeration Mechanism of Rich Hematite Sinter with Lowering SiO2 Content

The mini-sintering test was introduced. The experiments of specimens of rich hematite with lowering SiO2 content were carried out by the mini-sintering test. The strength and mechanism of agglomeration were studied mainly when silica content in sintered specimens was decreased gradually. The relationships between SiO2 volume and morphology of sinter were also investigated. It is considered that high grade sinter can be developed by raising sinter basicity so as to enhance complex calcium ferrite content or lowering sinter basicity so as to make Fe2O3 bonding for strength.     

降低柳钢烧结矿返矿率的实践

由于受原燃料影响,自2007年后,柳钢烧结矿返矿率大幅度上升,在同行业中处于较差水平。针对该现状,通过专项攻关,从烧结厂内部和外围采取措施,取得了一定效果。     

烧结矿断面图像分析与操作指导系统

应用图像处理与神经网络技术,根据烧结操作人员对烧结矿FeO含量判断的方法,应用CCD摄像机采集烧结机尾断面图像对其进行实时处理、特征提取,并由根据烧结看火工的经验知识训练的BP神经网络对图像分类辨识,得出相应的FeO、燃料、水份等参数,应用人工智能方法指导生产操作.     

尖晶石型LiMn2O4陶瓷的制备及其电导率

为研究尖晶石型LiMn2O4正极材料的导电性能,用无压、热压和等离子放电烧结的方法制备出了LiMn2O4陶瓷块体,用X射线衍射(XRD)、扫描电子显微镜(SEM)和交流阻抗谱研究了产物的物相、显微结构和电导率。结果发现,在高温或低氧浓度的烧结条件下LiMn2O4发生脱氧,分解生成LiMnO2和Mn3O4。通过埋粉工艺可以有效地抑制脱氧,提高LiMn2O4的烧结温度。等离子放电烧结可使坯体迅速达到致密,抑制晶格脱氧和晶粒长大。尖晶石型LiMn2O4的电导率由晶界电导控制,晶粒大小对电导率的影响很大。     

粉末烧结铝镍钴永磁合金的质量控制

分析了粉末烧结铝镍钴（AlNiCo）永磁合金的主要缺陷及对产品质量的影响;根据多年的生产经验,针对具体缺陷提出了改善方案。粉末烧结AlNiCo永磁合金中主要缺陷包括气孔、变形、夹杂脏化等。从理论和实际生产的角度分析了造成“脏化”的原因,针对不同类型的“脏化”提出了不同的解决方案。     

Push-Pull Fatigue of Sintered Silicon Nitride Ceramics at Elevated Temperatures

The fatigue tests under push-pull completely reversed loading and pulsating loading were performed for silicon nitride ceramics at elevated temperatures. Then the effects of stress wave form, stress rate, and cyclic understressing on fatigue strength, and cyclic straining behavior, were examined. The cycle-number-based fatigue life is found to be shorter under trapezoidal stress wave loading than under triangular stress wave loading, and to become shorter with increasing hold time under the trapezoidal stress wave loading. Meanwhile, the equivalent time-based life curve, which is estimated from the concept of slow crack growth, almost agrees with the static fatigue life curve in the short and intermediate life regions, showing the small cyclic stress effect and the dominant stress-imposing period effect on cyclic fatigue life. The fatigue strength increased in stepwise stress amplitude increasing test, where stress amplitude is increased stepwise every given number of stress cycles, at 1100° and 1200°C. Occurrence of cyclic strengthening was proved through a gradual decrease in strain amplitude during a pulsating loading test at 1200°C in this material, corresponding to the above cyclic understressing effect on fatigue strength.     

High-Q and temperature-stable microwave dielectrics in layer cofired Zn1.01Nb2O6/TiO2/Zn1.01Nb2O6 ceramic architectures

A multilayer cofired architecture was proposed and demonstrated to achieve high-Q and temperature-stable microwave dielectrics in a derived system, Zn_1.01Nb₂O₆-TiO₂. This approach could effectively allow the chemical reactions between Zn_1.01Nb₂O₆ and TiO₂ occur at a rather narrow area (~12 μm), the interfaces of heterogeneous layers, where the diffusion of Zn, Nb, and Ti could be observed. Such interfaces could act as the in situ “glues” to connect each layer well. The effects of stacking scheme and TiO₂ content on the microwave dielectric properties of layered architectures were investigated systematically. The resonant frequency, Q-factor, and electric field distribution were reported using the eigenmode solver of high-frequency structure simulator. Among the available layer architectures, the optimized microwave dielectric characteristic was observed in Zn_1.01Nb₂O₆/TiO₂/Zn_1.01Nb₂O₆ stacked with 0.058 mol TiO₂ (~1.84 vol%). The τ_f can be effectively tuned to approximately +0.53 ppm/°C, and importantly, a high Q × f value ~99 500 GHz together with ε_r ~26.8 was achieved. This design could be beneficial for opening up new ways to develop high-performance microwave dielectrics based on current material systems and therefore to meet with the high requirements for 5G wireless communication components and multilayer packing technology.     

Effect of P2O5 on the Nonisothermal Sinter‐Crystallization Process of a Lithium Aluminum Silicate Glass

Dense (~98.5%), lithium aluminum silicate glass‐ceramics were obtained via the sinter‐crystallization of glass particle compacts at relatively low temperatures, that is, 790–875°C. The effect of P₂O₅ on the glass‐ceramics' sinter‐crystallization behavior was evaluated. We found that P₂O₅ does not modify the surface crystallization mechanism but instead delays the crystallization kinetics, which facilitates viscous flow sintering. Our glass‐ceramics had virgilite (Li_xAl_xSi_3‐xO₆; 0.5 < x < 1), a crystal size <1 μm, and a linear thermal expansion coefficient of 2.1 × 10^?6°C^?1 in the temperature range 40–500°C. The overall heat treatment to obtain these GCs was quite short, at ~25 min.