单晶拉伸炉的自动化控制系统的设计

文章针对某单晶拉伸炉的现状及存在的问题,介绍了一种经济实用的单晶炉自动化控制系统.对系统的组成和特点、数据的测量和转换作了详细的描述.该系统能针对不同外界条件进行控制,大大提高了系统的抗干扰能力,控制效果良好,保障了单晶炉的稳定运行和不同批次之间单晶管的性能.这套装置具备成本低、抗干扰能力强、控制性能好等特点,且控制系统硬、软件维护简单方便.     

硅单晶炉副室清炉机构设计

为了解决现有硅单晶炉副炉室清理中存在的问题,提高清炉的效率,降低工人的劳动强度,设计了一种方便的清炉机构.该机构操作简单、方便、实用.     

外部机械化室式炉装取料机的设计

简单介绍了国内大口径无缝管的生产现状及外部机械化室式炉的特点。详细阐述了外部机械化室式炉用装取料机的设备组成、工作过程及各组成部分的结构特点及功能。     

CZ单晶炉单晶等径生长计算机控制系统

介绍了ＣＺ单晶炉单晶等径生长计算机控制系统的硬件结构和软件设计原理。     

单晶炉低速动平衡

生产高精度硅晶体的单晶炉,其上部的籽晶提升机构为转轴竖直安装的非对称低速旋转机构,生产过程中下面软轴的摆动幅度是衡量单晶炉性能的重要参数之一,如果摆动过大,将直接影响所生产的硅晶体的质量.动不平衡是造成软轴摆动的重要原因之一,采用激光测振仪测量籽晶提升机构微小振动量,用影响系数法对单晶炉籽晶提升机构进行现场整机动平衡,减小了该机构振动对软体摆动的影响,提高了所拉晶体的质量.     

单晶炉机械传动系统综述

机械传动系统是单晶炉的重要组成部分,它主要包括坩埚升降与旋转系统、籽晶升降与旋转系统等等。本文详细论述了这两种传动系统的典型方案及其传动机理,最后阐明各单晶体生长方法所要求的传动系统。     

双作用气缸在单晶炉中的应用

介绍了单晶炉的主要机械结构以及气缸的基本知识,根据目前单晶炉设备所需要的自动化程度的不断提高．介绍了双作用气缸在单晶炉中翻板隔离阀处阀盖开、关机构上的应用。     

单晶拉仲炉的自动化控制系统的设计

文章针对某单晶拉伸炉的现状及存在的问题,介绍了一种经济实用的单晶炉自动化控制系统。对系统的组成和特点、数据的测量和转换作了详细的描述。该系统能针对不同外界条件进行控制,大大提高了系统的抗干扰能力,控制效果良好,保障了单晶炉的稳定运行和不同批次之间单晶管的性能。这套装置具备成本低、抗干扰能力强、控制性能好等特点,且控制系统硬、软件维护简单方便。     

基于SolidWorks的单晶炉二次加料装置改进设计

研究了单晶炉二次加料装置的原理和结构,并在此基础上使用三维建模设计软件SolidWorks对其进行了三维设计。根据二次加料装置的工作原理,分析了现有装置的存在的主要问题和改进方案,以SolidWorks软件为平台,先建立了单个零件的三维模型,然后通过虚拟装配得到装配体的三维模型,并经过图形转换得到了生产实际中应用的二维工程图。通过运用三维设计软件SolidWorks,使设计在改进总体外观造型的同时工作效率也明显提高,具有较高的实用价值。     

单晶炉压力自动控制系统的实现

根据硅单晶炉真空系统技术特点,从炉内真空系统的抽气、充气控制等方面进行改进和完善,并采用带有前馈的PID算法实现压力的自动控制。结合工业PLC和人机界面进行编程,在实际工业中的应用表明,该压力自动控制系统可保证炉内真空达到高稳定性,拉出高品质单晶。     

基于遗传算法的单晶炉热场温度控制系统

介绍了以AT89C51单片机为核心的单晶炉热场温度控制系统的设计与实现方法,提出了一种基于遗传算法的PID参数寻优方法。仿真研究结果表明,系统具有良好的控制性能。     

基于DMC算法的单晶炉热场温度控制系统

介绍了以AT89C51单片机为核心的单晶炉热场温度控制系统的组成及工作原理.研究了动态矩阵控制(DMC)算法在单晶炉热场温度控制系统中的应用.给出了系统的硬件与软件设计的实现方法.研究表明,与PID控制结果相比较,应用动态矩阵控制算法能使系统具有更好的控制性能.     

基于单神经元自适应PID的电机绕组炉温控制系统设计

设计了1套基于单神经元自适应PID的电机绕组烘干炉炉温控制系统,系统包括硬件控制电路和基于单片机的炉温控制程序。该系统应用于大滞后的电阻炉炉温控制,取得了良好的控温效果。试验表明：与传统的PID炉温控制系统相比该系统具有鲁棒性强、响应快、控制精度高,控制质量可靠等优点。     

Evaluation method of multiaxial low cycle fatigue life for cubic single crystal material

The coupling effect of normal stress and shear stress on orthotropic materials happens when applied loading deflects from the directions of the principal axes of the material coordinate system. By taking account of the coupling effects, formulas of equivalent stress and strain for cubic single crystal materials are cited. Using the equivalent strain and equivalent stress for such material and a variable k, which is introduced to express the effect of asymmetrical cyclic loading on fatigue life, a low cycle fatigue (LCF) life prediction model for such material in multiaxial stress starts is proposed. On the basis of the yield criterion and constitutive model of cubic single crystal materials, a subroutine to calculate the thermo elastic-plastic stress-strain of the material on an ANSYS platform was developed. The cyclic stress-strain of DD3 notched specimens under asymmetrical loading at 680°C was analyzed. Low cycle fatigue test data of the single crystal nickel-based superalloy are used to fit the different parameters of the power law with multiple linear regression analysis. The equivalent stress and strain for a cubic single crystal material as failure parameters have the largest correlation coefficient. A power law exists between k and the failure cycle. The model was validated with LCF test data of CMSX-2 and DD3 single crystal nickel-based superalloys. All the test data fall into the factor of 2.5 for CMSX-2 hollow cylinder specimens and 2.0 scatter band for DD3 notched specimens, respectively.     

单晶金刚石刀具刃磨信号监测技术研究

单晶金刚石刀具在刃磨过程中,不同晶面,晶向以及工艺参数会对发出的噪声和振动信号有所影响。分析刃磨工艺条件、噪声和振动信号以及刃口质量之间的相互关系,将有助于更加深入地了解刀具刃磨技术,提高刀具制造水平。     

Study of EDM cutting of single crystal silicon carbide

Electrical discharge machining (EDM) is developing as a new alternative method for slicing single crystal silicon carbide (SiC) ingots into thin wafers. Aiming to improve the performance of EDM slicing of SiC wafers, the fundamental characteristics of EDM of SiC single crystal were experimentally investigated in this paper and compared to those of steel. Furthermore, EDM cutting of SiC ingot by utilizing copper foil electrodes was proposed and its performance was investigated. It is found that the EDM characteristics of SiC are very different from those of steel. The EDM machining rate of SiC is higher and the tool wear ratio is lower compared to those of steel, despite SiC having a higher thermal conductivity and melting point. Thermal cracks caused by the thermal shock of electrical discharges and the Joule heating effect due to the higher electrical resistivity are considered to be the main reasons for the higher material removal rate of SiC. It is concluded that the new EDM cutting method utilizing a foil electrode instead of a wire electrode has potential for slicing SiC wafers in the future.     

LCF behavior and life prediction method of a single crystal nickel-based superalloy at high temperature

Low cycle fatigue tests were conducted on the single crystal nickel-based superalloy, DD6, with different crystallographic orientations (i.e., [001], [011], and [111]) and strain dwell types (i.e., tensile, compressive, and balanced types) at a certain high temperature. Given the material anisotropy and mean stress, both orientation factor and stress range were introduced to the Smith, Watson, and Topper (SWT) stress model to predict the fatigue life. Experimental results indicated that the fatigue properties of DD6 depend on both crystallographic orientation and loading types. The fatigue life of the tensile, compressive, and balanced strain dwell tests are shorter than those of continuous cycling tests without strain dwell because of the important creep effect. The predicted results of the proposed modified SWT stress method agree well with the experimental data.     

Optimal design of high temperature vacuum furnace using response surface method

A new method using the response surface method and optimization technique has been developed instead of the original method based on trial and error. In order to construct a response surface, thermal analysis was performed under the condition of using the calculated thermal conductivity of the insulator in a previous study. In order to set up the response surface, the D-Optimal method was used in the process of selecting experimental points. Using a weighting factor, an optimization study was carried out under the condition of satisfying user requirements. Finally, the merits and drawbacks of the new method were described by comparing with the optimal design method based on the thermal analysis database which was developed in a previous study. The optimal results show that the developed method can be used to design an energy efficient, low manufacturing cost, high temperature vacuum furnace with avoiding unnecessary iterative manufacturing, and anticipating the performance before manufacturing. This paper was recommended for publication in revised form by Associate Editor Ohchae Kwon     

新型PID参数选取方法在加热炉控制中的应用

加热炉煤气流量控制属于经典过程控制,最适宜的控制方案是PID控制,但利用传统的控制器参数整定方法,目标跟踪特性和干扰抑制特性不能兼顾。该文介绍一种新型PID参数选取方法,经仿真控制效果较好。