Compositional Optimum Design and Experimental Investigation of Rare Earth Containing Ceramic Composite

Based on the Al2O3/(W,Ti) C ceramic material, optimum design of the material compositions were carried out, which includes the theoretical calculation of the critical volume fraction of the reinforcement phase, and the optimum design based on the impact resistance, thermal shock resistance and wear resistance, etc. It is found that the optimum volume fraction of (W,Ti)C is 31.2%, 32.8% and 34%, respectively, which is corresponding with the best impact resistance, thermal shock resistance and wear resistance. After comprehensive consideration, the optimum volume fraction of (W,Ti)C in Al2O3/( W, Ti)C ceramic material is finally determined to be 30%. Then, effects of the content of rare earth yttrium on the mechanical property of the Al2O3/30vol% (W,Ti)C ceramic material were investigated experimentally. It indicates that when the content of yttrium is 0.25% ～ 0.5%, both flexural strength and fracture toughness of the rare earth containing ceramic material are further improved with the increment of approximately 10% ～16%.     

连续陶瓷纤维的应用前景

本文介绍了连续陶瓷纤维,尤其是Al_2O_3-SiO_2系氧化物连续陶瓷纤维最近的发展情况。溶胶—凝胶法近年来受到广泛关注,采用此法能获得高纯度连续陶瓷纤维材料,其使用温度可达1400℃。此类纤维的应用目前已遍及许多领域,CFCC计划的实施将使其潜在的节能及环境保护效能得到发挥。     

激光熔覆稀土陶瓷涂层进展

综述了激光熔覆稀土陶瓷涂层研究现状及其最新进展。介绍了激光熔覆工艺特点和影响因素,激光熔覆工艺包括粉末材料的加入方法和激光辐照加工。加入方法分预置法和同步送粉法,工艺参数包括光斑尺寸、扫描速度、熔覆道次、送粉量、涂层厚度和搭接量等。研究认为正确选择工艺参数是保证熔覆层质量和性能的关键。总结了稀土添加剂的强化作用机制,其主要作用为微合金化、净化晶界、细化晶粒、改善晶界状态、抑制柱状晶生长。对激光熔覆稀土陶瓷涂层研究的发展进行了展望。     

铝电解惰性阳极材料选择的研究

论述了传统碳素阳极的缺点及使用惰性阳极的意义,提出了惰性阳极材料应符合的要求。综述了国内外对金属氧化物陶瓷阳极、金属陶瓷阳极、金属阳极的研究成果,并总结了以上三类惰性阳极有待进一步解决的主要问题。     

一种新型超磁致压电混合精密位移机构的研究

为了研究大步距高精度精密位移机构,利用超磁致伸缩材料和压电陶瓷材料在驱动原理和使用方法上的相似性,提出一种超磁致伸缩材料与压电叠堆组成的混合驱动精密位移机构,介绍了机构运动原理及控制方式,制作了试验样机.测试表明,所研制的混合精密位移机构能实现双向可控运动,单步前进最大位移可达20μm,调节驱动电压可控制单步位移量,能满足大步距、高精度的驱动要求.     

颗粒弥散陶瓷的内应力分布及光弹性分析

本文详细分析了颗粒增强复相陶瓷内部的应力大小及分布状态，建立了单种颗粒及多种颗粒复合时瓷体的残余应力模型，并通过计算机模拟其应力的平面分布，采用光弹性应力分析加以验证．     

自焙炭块在大型高炉上应用十年概况

自焙炭块陶瓷砌体复合炉缸技术在大型高炉上的应用已有10年，总的来说是成功的，但由于自焙炭块自身的特性，应用中也暴露出了一些问题。通过对国内大型高炉应用自焙炭块陶瓷砌体复合炉缸技术的全面调查，分析了该技术的应用前景，提出了改进措施。     

Spectroscopic and structural properties of MgAl_2O_4:Nd~(3+) nanopowders and ceramics

The structural and spectroscopic properties of MgAl2O4:1%Nd3+ spinel nanocrystals and ceramics were measured and analyzed. Ceramics were prepared from the above mentioned spinel nanocrystals and undoped commercial spinel powder, using the spark plasma sintering(SPS) method. Properties of the obtained ceramics strongly depended on the SPS conditions. The samples were not homogeneous and possessed defects and pores. The most transparent ceramics had 60% transparency at 1000 nm.     

CeO2对不锈钢基SiO2-BaO-Al2O3-Cr2O3陶瓷涂层性能的影响

采用高温熔烧法于1Cr18Ni9Ti不锈钢基材表面制备掺CeO2的SiO2-BaO-Al2O3-Cr2O3陶瓷涂层,研究了不同含量CeO2对涂层的抗氧化性、抗热震性和硬度的影响。研究结果表明,含CeO2的不锈钢基SiO2-BaO-Al2O3-Cr2O3陶瓷涂层能有效阻止不锈钢基体的氧化增重,提高涂层的抗热震性能及硬度。本实验条件下,CeO2含量2.8%时,涂层具有最好的抗氧化性能和抗热震性能。     

三元层状可加工陶瓷Ti_2AlN的研究进展

对三元层状可加工陶瓷Ti2AlN的电子结构及其力学、抗氧化和热电等性能方面的研究进行了综述。重点阐述了Ti2AlN与Ti2AlC相比,其断裂韧性和维氏硬度较低而电导率较高的原因,介绍了Ti2AlN的制备现状与应用前景。