超声波在陶瓷无损检测中的应用

介绍了超声波的发展及其特点,利用超声波检测陶瓷的基本原理对陶瓷气孔率和表面缺陷进行检测,并指出了今后应加强研究的方向。     

关于陶瓷原料预均化技术的若干探讨

首先对陶瓷原料的组成波动的统计特征进行了分析,接着介绍了预均化的原理、方式,以及对预均化效果的评估方法及其指标,最后给出了国内一家陶瓷公司对粘土原料预均化的实例及其效果评价,可供拟开发应用原料预均化技术的用户参考。     

Coating of SiC Powder with Nano YAG Phase

SiCceramiccompositeshavefoundextensiveap plicationsinmodernindustryduetotheirexcellentchemicalstabilityandwear resistance .Rodeghieroetal.[1～ 3 ] investigatedthefabricationofSiC Al2 O3 ce ramiccompositematerialsviaco precipitationcoatingandsol gelmethods…     

从铁元素在瓷器中的作用看陶瓷材料中的“辩证法”

从青瓷到黑瓷、白瓷,Fe2O3含量起着决定性的作用。黑瓷的烧制成功,是利用了铁元素含量高的一面,并达到了最大端点;白瓷的烧制成功,是利用了铁元素低的一面,达到另一端点;黑白与游弋在黑白之间的Fe2O3含量构成了陶瓷材料中完整的辩证法。     

Effect of magnesium and nickel coatings on the wetting behavior of alumina toughened zirconia by molten Al-Mg ahoy

The wettability of alumina toughened zirconia (ZTA) by Al-Mg alloy was investigated using the sessile drop technique.The effects of nickel coating,magnesium content,nitrogen atmosphere,and processing temperature on the contact angle between the molten alloy and the substrate were determined.Likewise,the effect of these factors on the wetting properties was studied.The results showed that the nickel coating on the ceramic substrate caused a significant reduction in solid/liquid surface energy and the contact angle decreased obviously.The presence of magnesium in the molten aluminum alloy in nitrogen atmosphere reduced the contact angle effectively.The presence of magnesium in the alloy must be at a minimum amount of 2wt％-3wt％.Moreover,it was suggested that some chemical reactions in the Al-Mg-N system led to the production of Mg3N2 and A1N compositions.These compositions improved the wetting properties of the systems by reducing the surface energy of the molten.It was shown that increasing the temperature is also an effective factor for the enhancement of wetting properties.     

陶瓷-硬质合金复合刀片材料的力学性能与界面结构

采用热压烧结工艺制备了刀具用陶瓷－硬质合金复合片．复合片上层为具有一定厚度的Ａｌ２Ｏ３／ＴｉＢ２陶瓷材料，下层为ＷＣ／Ｃｏ硬质合金．结果表明：复合片综合了陶瓷材料的高硬度和硬质合金的高强度，其性能介于陶瓷材料和硬质合金之间．Ｘ射线衍射、电子探针和扫描电子显微镜分析表明：烧结过程中硬质合金和陶瓷材料中的元素在界面相互扩散，并有新相形成，增加了界面结合强度，其界面为化合物型和扩散型的混合．     

陶瓷材料的烧结方法

陶瓷材料的烧结方法是决定其最终性能的关键技术 ,本文系统的介绍、分析了目前陶瓷材料所采用的各种烧结方法的机理、工艺、影响因素、特点及其使用范围 ,为陶瓷材料烧结方法的选择提供参考     

基于数据库的陶瓷材料计算机辅助设计

根据已知文献的数据建立了陶瓷材料性能和组分数据库 ,开发了管理和操纵该数据库的应用程序 ,利用该程序可以查询已知陶瓷材料系统性能与组分的关系 ;建立了基于该数据库的人工神经网络预测模型 ,通过操纵陶瓷材料数据库中相关数据 ,并结合人工神经网络预测模型程序可以预测未知材料系统在给定性能条件下的各相组分 ,预测了Al2 O3 (W ,Ti)C陶瓷材料在两种目标性能下的组分 ,并计算了其预测误差 ,结果表明 ,其实验值与预测值较为吻合。     

Spin Dependent Hopping in Ti Doped La0.67 Ca0.33 MnO3

A systematic investigation of the magnetic and transport properties of Ti doped La0.67Ca0.33MnO3 was reported. The Ti substitution for Mn ions results in a reduction in ferromagnetism and conductivity. The metal-insulator transition temperature is close to Curie temperature which decreases from 274 to 82 K as x increases from 0 to 0.17. The most important effect of Ti doping is to introduce spin clusters in the samples due to the distortion of local lattice and the inhomogeneous magnetic structure induced primarily by the random distribution of Mn ions. A maximum magnetoresistance ratio as large as 90% in 1 T at 122 K was obtained for the sample with x =0. 055, which is four times larger than that obtained for LCMO sample at 272 K. There is a remarkable field-history dependent MR in the cooling process for the doped samples while such phenomenon disappears in the warming run. The resistivity follows well the variable range hopping behavior in paramagnetic state. Both the size effect and spin dependent hopping of carriers between the spin clusters should be considered in this system.