基于单片机的连续烧结炉的多点温度控制

介绍了一种以单片机AT89C52为核心的多点温度控制系统的设计方案;采用美国TI公司的逐次逼近型A/D转换器TLC2543进行串行数据采集与转换;同时介绍了系统的软硬件结构。采用软硬件滤波方法,抗干扰性强;节省资源,可靠实用。     

封装技术的发展-电力电子器件中的新尺寸

赛米控将银烧结工艺代替了芯片和DBC之间的焊接绑定线,这项新技术的使用将使得生产出体积比最先进系统切实减小30%的逆变器成为可能。这项技术的优势将在具有最佳机械一体化的集成、紧凑型系统中得到最好的展现。     

三维微流道系统技术研究

采用LTCC技术,可以获得替代采用硅或其他技术制作的微功能结构,简化工艺,降低成本.重点研究了内嵌三维(3D)微流道系统LTCC多层基板成型中的关键技术:热压和烧结,并进行工艺优化.利用优化的热压、烧结工艺参数,可制备出完好的3D微流道系统LTCC多层基板;通过实验验证,LTCC内嵌三维微流道系统取得了良好的散热效果.     

Effect of current on the microstructure and performance of (Bi_2Te_3)_(0.2)(Sb_2Te_3)_(0.8) thermoelectric material via field activated and pressure assisted sintering

(Bi_2Te_3)_(0.2)(Sb_2Te_3)_(0.8) thermoelectric material was sintered via a field activated and pressure assisted sintering(FAPAS) process.By applying different current intensity(0,60,320 A/cm~2) in the sintering process,the effects of electric current on the microstructure and thermoelectric performance were investigated.This demonstrated that the application of electric current in the sintering process could significantly improve the uniformity and density of(Bi_2Te_3)_(0.2)(Sb_2Te_3)_(0.8) samples.Whe...     

高Q值铜内电极MLCC的研制

以铜为内电极和端电极,制备了NPO MLCC.研究了陶瓷粉体成分、内电极材料和烧结工艺对所制MLCC性能的影响.结果表明:选用Mg-Si-O3系瓷粉匹配纯铜内电极浆料,在弱还原气氛保护下进行低温(900～1 020℃)烧结,所制MLCC样品电性能良好,成本低,其中,0603规格10pF样品在1 GHz下的Q值高达60、...     

BaCu(B2O5)的添加对Li2MgTi3O8微波介质陶瓷性能的影响

采用传统固相反应法制备Li2MgTi3O8微波介质陶瓷,研究了BaCu(B2O5)(简称BCB)的添加对Li2MgTi3O8微波介质陶瓷的烧结性能及介电特性的影响.结果表明:BCB作为低熔点氧化物烧结助剂,可有效降低所制陶瓷烧结温度,而且可以调节τf近零.当添加质量分数3％的BCB,900℃烧结所制陶瓷的综合微波介电性...     

锌硼玻璃基低温共烧陶瓷的微波介电性能研究

采用3ZnO-2B2O3玻璃与Al2O3和TiO2复合烧结制备了锌硼玻璃基低温共烧陶瓷复合材料,研究了TiO2/Al2O3质量比对所制复合材料相组成和微波介电性能的影响.结果表明:随着TiO2/Al2O3质量比减少,复合材料中ZnAl2O4相含量增多,TiO2相含量减少,4ZnO·3B2O3相的含量基本不变.随着TiO...     

3D finite element simulation of the matter flow by surface diffusion using a level set method

Within the context of the sintering process simulation, this paper proposes a numerical strategy for the direct simulation of the matter transport by surface diffusion, in two and three dimensions. The level set formulation of the surface diffusion problem is first established. The resulting equations are solved by using a finite element method. A stabilization technique is then introduced, in order to avoid the spurious oscillations of the grain boundary that are a consequence of the dependence of the surface velocity on the fourth‐order derivative of the level set function. The convergence and the accuracy of this approach are proved by investigating the change in an elliptic interface under surface diffusion. Cases in direct relation with the sintering process are analyzed besides: sintering between two grains of the same size or of two different sizes. Finally, 3D simulations involving a small number of particles show the ability of the proposed strategy to deal with strong deformations of the grain surface (formation of necks) and to access directly important parameters such as the closed porosity rate. Copyright © 2010 John Wiley & Sons, Ltd.     

基于RBF神经网络的烧结终点预报系统

为稳定烧结机运行工况,提高烧结矿的产量和质量,需要将烧结终点控制在一个相对稳定的范围,因此准确预报烧结终点对烧结生产具有重要意义。分析了烧结工艺流程及烧结终点的确定原则,建立了基于RBF神经网络的烧结终点预报模型。根据影响烧结终点的工艺参数,提取了与烧结终点关联的5个特征量作为网络的输入量。用现场采集的生产工艺参数对模型进行训练,仿真分析验证了模型预报的有效性。     

铝土矿生料浆烘干与烧结特性的试验研究

在试验室条件下,参照国外研究成果,结合我国碱石灰烧结法氧化铝生产实际,从生料浆黏度变化规律、生料浆烘干过程及生料浆烧结特性等方面进行了试验.研究试验结果表明:真钙比的变化对同一水分下生料浆黏度的影响不明显,当生料将水分＜38％时,生料浆水分和生料浆温度升高对生料浆黏度值影响较大;气态悬浮干燥器中料浆烘干温度应不低于60...