磁控溅射中的海绵卷绕设备研究

在大量试验的基础上，总结了磁控溅射中海绵的传动特性，设计了微张力海绵卷绕系统，建立了传动控制的数学模型，经大量试验和使用证明，该设计满足了磁控溅射中海绵卷绕的要求。     

卷绕式海绵材料真空磁控溅射镀膜设备的研制

本文介绍了海绵卷绕真空磁控溅射镀膜设备的结构及其特点，采用独特的传动机构，靶极结构及控制方式实现了海绵连续卷绕真空磁控溅射镀膜。     

卷绕传动的力学分析及控制

卷绕传动普遍应用于染整工艺过程中。传动时张力常产生波动,影响产品质量和生产效率。论文针对张力波动现象,对卷绕传动进行了力学分析,并采用矢量控制变频技术对其进行控制,提出了一个实用的经验公式,以实例证明了其力学分析及经验公式是正确的,所采取的控制方式效果令人满意。论文表明,应用矢量控制变频技术控制张力,具有实用价值,可以推广到类似的传动中去。     

塑料ITO膜磁控溅射卷绕镀膜机的研制

本文介绍了塑料 ITO膜磁控溅射卷绕镀膜机的研制 ,就采用磁控溅射卷绕法制备 ITO膜的设备及成膜过程的一些工艺问题进行了探讨     

海绵镀膜卷绕系统的设计

海绵卷绕系统是真空法连续镀制泡沫镍成套设备的重要组成部分之一,本文主要介绍了海绵卷绕系统的设计及其特点.     

计算机控制在真空海绵镀镍设备中的应用

详细介绍了国内第一台高真空连续卷绕海绵镀镍设备的电气控制系统及工业控制计算机和PLC在该系统中的应用.     

真空卷绕镀膜技术研究进展

本文从系统结构、参数控制和镀膜方式等综述了真空卷绕镀膜技术研究进展。按结构可分为单室、双室和多室真空卷绕系统,后两者可解决开卷放气问题并分别控制卷绕和镀膜室各自真空度。卷绕张力控制分锥度、间接和直接控制模型,锥度控制模型可解决薄膜褶皱和径向力分布不均的问题;间接张力控制无需传感器,可用内置张力控制模块的矢量变频器代替;直接张力控制通过张力传感器精确测量张力值,但需惯性矩和角速度等多种参数。真空卷绕镀膜主要有真空蒸发、磁控溅射等方式,可用于制备新型高折射率薄膜、石墨烯等纳米材料和柔性太阳能电池等半导体器件。针对真空卷绕镀膜技术研究现状及向产业化过渡存在的问题,最后作了简要分析与展望。     

第二十一讲真空卷绕镀膜

(接2021年第6期88页) 3.4 中频磁控卷绕镀膜 中频磁控卷绕镀膜是利用中频磁控溅射技术来实现卷绕镀膜的方法.中频交流磁控溅射通常采用两个尺寸大小和外形相同的靶并排布置或相对摆放,称为孪生靶.将双极脉冲中频电源的二个输出端连接到二个靶上,如图18所示.     

真空卷绕镀膜机开卷张力控制系统研究

阐述了在真空卷绕镀膜机中张力控制的必要性和复杂性。通过机理建模的方法建立了开卷区张力控制模型,从中得出影响张力的相关因素,并提出了一种利用间接控制方式设计卷绕镀膜机开卷张力控制系统的方法。从张力给定和张力控制两方面,对控制系统设计过程中相关控制量及补偿量的计算方法给出了具体算式和详尽说明。实践表明,该控制系统结构简单,控制精度高,响应速度快且稳定性好。     

中试涂布机的电气传动控制

本文阐述彩色感光材料生产中的关键设备——涂布机多电机协调传动的设计问題,介绍了电流、速度、张力三环控制中调节器的计算,运用现代控制论中二次型性能指标最优控制及传统的二阶、三阶最佳控制系统工程设计法的使用。对于诸如造纸机、塑料涂敷机、铝箔卷绕机等多机分部传动具有一定的参考价值。     

有限差分法和数值模拟在热轧带钢层流冷却中的应用

针对传统的热轧带钢层流冷却卷曲温度控制中数学模型的固有缺陷，分别采用了差分方程和有限元数值模拟的方法，建立带钢厚度方向上的温度场。结果表明：考虑带钢与介质的热交换的同时再考虑带钢内部的热传导是必要的，为定量地描述计算值与实测值之间的偏差提供了参考。     

Acoustic emission and disturbances in central solenoid model coil for International Thermonuclear Experimental Reactor

This paper presents acoustic emission (AE) signals induced from the Central Solenoid (CS) model coil of the International Thermonuclear Experimental Reactor (ITER) program. Envelopes of the AE signals were quasi-continuously measured with high-time resolution of 100 μs using six multi-channel AE sensors in order to detect the disturbances in the CS model coil during the process of the series of direct current (DC) operations. The AE signals were considered to be originally induced by motion of superconducting cables in cable-in-conduit (CIC) conductors and local motion of the conductors, judging from the close correlation between the AE signals and voltage spikes in the coil, especially during the virgin current operation. The multi-channel measurements provide us with information about the distribution of disturbances that could be detected acoustically by the AE sensors installed at each point of the CS model coil. The observation of AE envelopes with high-time resolution showed that the disturbances at each location of the CS model coil decreased by repeatedly charging-up the coil, judging from instantaneous AE levels, AE energy and the number of AE events. Direct measurements of the number of AE events that were carried out at another point on the coil confirmed that the disturbance dependence on the number of operations was similar to that mentioned above. The transfer function methods using one pair of AE sensors enabled us to analyze changes that might occur in either the coil structure or in the disturbance in frequency region during the repeating of the charging-up processes of the coil.     

Design of Complex Sheet Metal Forming Processes: A New Computer Aided Progressive Approach

Ridge-buckle defects in cold rolled thin strip originate from the formation of ridges in hot rolled coil and corresponding ridges left in the strip following annealing, cold rolling and tempering. A numerical solution was developed to calculate three-dimensional stress distribution in a wound coil built up wrap-by-wrap and subsequent flatness change in the uncoiled product. The model takes into account both nonlinear compressible characteristic of interwrap layer and uneven strip profile, especially ridges, on the stress evolution during the coiling process. The sensitivity of ridge-buckle defects in cold rolled thin strip to ridges in hot rolled coil profile has been investigated in details. The results show that the ridge-buckle defects in tin plate are much dependent on the height, width and location of ridges in hot coil profile. The permissible tolerance of ridges in hot rolled coil, below which does not produce the ridge-buckle defects in subsequent cold rolling of thin strip, are recommended for different steel grades.     

冷轧铝带卷取内部应力有限差分仿真研究

目的研究冷轧铝带卷取内部应力的分布情况以及影响因素,为铝带卷筒的设计提供参考。方法通过冷轧铝板压缩实验,测定铝带径向压缩系数与应力的关系曲线;采用非线性有限差分法对卷取过程和内部应力进行仿真;分析线性、一次非线性和二次非线性材料模型以及卷筒刚度对带卷内部应力分布的影响。结果径向压缩系数的理论值与实验值有较好的一致性,卷筒刚度对铝带卷内层应力影响较大,而对外层影响很小,卷筒刚度较小时,在卷芯处容易产生塌卷缺陷,卷筒刚度较大时,容易出现扁卷现象。结论计算带卷内部应力分布时,需要考虑铝带卷的各向异性以及层与层之间的紧密程度,合理选择卷筒的刚度对提高卷取质量有很大的实际意义。     

Analysis of sheet steel fracture during deep drawing

Low-carbon steel sheet used for the fabrication of automotive brake components was tearing during deep drawing. The associated mill certificates revealed that the coil met the specified chemical composition and mechanical properties. Metallographic evaluation revealed a severe variation with respect to grain size through the thickness of the steel sheet, as well as a slight segregation of pearlite. Insufficient temperature during hot rolling in combination with a high coiling temperature resulted in the observed microstructural gradient. The anisotropic mechanical properties were amplified by the slight carbon segregation.     

Dynamic Modeling and Control of a Piezo-Electric Dual-Stage Tape Servo Actuator

We present a data-based approach for modeling and controller design of a dual-stage tape servo actuator. Our method uses step response measurements and a generalized realization algorithm to identify a multivariable discrete-time model of the actuator. The data acquisition and modeling can be implemented in the servo firmware of a tape drive. We have designed a dual-stage controller, based on the model, using loop shaping techniques adopted for multivariable control problems. We applied the procedure to the prototype of a dual-stage actuator tape head to reduce the effect of lateral tape motion. The prototype consists of a conventional voice coil motor for coarse positioning and a micro-actuator for fine positioning. The micro-actuator, which is mounted on the voice coil motor, uses a piezo crystal to follow high-frequency lateral tape motion (up to the kilohertz regime), while the voice coil motor follows only low-frequency lateral tape motion. Compared to a single-stage design, the dual-stage servo design provides a 25% bandwidth improvement and a voice coil motor control signal that is much smaller in magnitude.      

Investigating the Drag Force of Luffa Tendril Due to Free Coiling

Abstract: Tendrils of some species of plants freely coil between their bases and tips to drag up the shoot and ensure no waste of shoot growth. In this study, the drag force generated by tendrils of the luffa plant (Luffa cylindrica) during free coiling was evaluated using a force measurement system that consisted of cantilever wire apparatus, CCD camera and finite element analysis software. How the stiffness of an object to which is attached the tip of tendrils affects the development of drag force because of free coiling was investigated. Experimental results showed that the tendril attached to a stiffer support could take longer to develop drag force and generate stronger drag force than one attached to a less stiff support. The drag force developed by free coiling of the luffa tendril could be on the order of 0.17 N. This force is sufficient to pull up more than eight times the internodal weight of the luffa shoot without other support. The relation between the magnitude of drag force generated by free coiling and the contraction ratio of the tendril was elucidated. The drag force–time curves show that the rate of increase in drag force resulting from free coiling of luffa tendrils in the first 20 h is higher than that after 20 h.     

Morphologies of carbon micro-coils grown by chemical vapor deposition

The carbon micro-coils were obtained by the Ni-catalyzed pyrolysis of acetylene. The carbon micro-coils with various coiling morphology: regular double coils, coils built up by circular or flat fibers, super helix coils, single coils, etc. can be observed. The carbon coils with various coil diameters and coil pitches were obtained by controlling reaction conditions, such as reaction temperature, source gas flow rate of sulfur-impurity, acetylene or hydrogen.     

Genesis of High Hardness in Hot-Rolled Coils of Cold Reducers’ Grade Steels

A significant quantity of cold-reducible hot-rolled (HR) coils is produced every year. These are basically low-carbon steels; however, the quality of HR coils with respect to cold reducibility had not been entirely satisfactory. The hardness of HR coil was generally higher (≥65 HR_B) than desirable for attaining satisfactory cold reducibility. A systematic study was, therefore, undertaken with the objective to control the hardness to ≤55 HR_B by modifying the existing chemistry, finish rolling temperature (FRT), and the coiling temperature (CT). To find the optimum conditions for lower hardness, trial rolling of slabs of cold reducers’ grade of selected chemistry was conducted under varied conditions. An assessment of hardness across the width and of the microstructure was carried out. The evolution of microstructure in the HR band at different locations from the edge of the strip and the genesis for the resulting hardness profile across the width of the HR coil were examined in detail. The influence of grain size on hardness was also analyzed. The paper outlines the role of finish rolling temperature, coiling temperature, chemistry, and grain size in restricting the hardness to values below 55 HR_B.