共查询到20条相似文献,搜索用时 78 毫秒
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对国内外电流脉冲加热技术的发展状况进行了综述评价.针对获取温度方法不同,主要介绍了黑体法、积分球法和激光偏振法三种基本形式的测量系统,进而介绍了扩展参数测量装置.又较为详细地介绍了作者自己研制的测量装置和特点.最后作者展望了电流脉冲加热技术的最新研究动态和发展方向. 相似文献
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实验证明采用局部加热技术对提高制什表面质量和品质,解决ABS、闪光铝共混材料制作产品注塑工艺中的熔接痕问题,不论在理论上,还是在实践中都是可行的。 相似文献
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在国家“十二五”发展规划的高端装备制造业中,高品质工业铝型材产品是实现大飞机、汽车、轨道交通列车、航天、军工、船舶等工业先进装备技术升级和国产化目标的关键基础材料。由于使用铝合金装备的轨道交通机车可降低车辆质量50%,实现节能约12%,增加运力10%左右,加之发达国家铝合金型材加工水平发展较快, 相似文献
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料层厚度是立磨操作非常重要的一个工艺参数。莱歇在心胆6.2+2CSgr磨上采用德国巴鲁夫(BALLUFF)BTL5-E10-M0150-P-S32型微脉冲位移传感器,用于磨内物料厚度测量,取得了非常好的应用效果。依据实际工作经验,在此对该传感器仪表在莱歇立磨中的应用及一些注意的问题浅加论述,供借鉴参考。 相似文献
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本研究提出了一种新的制备功能梯度材料方法,采用以脉冲当地惯性力为主动力的粉体脉冲微喷射技术来进行Ti/HA(Hydroxyapatite)功能梯度结构的牙根植入材料粉体按需输送制备实验。搭建了功能梯度材料制备实验系统,并对两种粉体在该系统下的输送率进行标定,利用标定的结果在制备的过程中进行相应的系统参数设定从而实现按需输送,并通过控制三维工作台的运动实现粉体根据设定的路径逐层堆积,最终通过压制与烧结得到所设计的具有一定强度的功能梯度材料。对所制备的功能梯度材料进行初步的力学性能与微观组织结构检测,评价其可行性并为进一步的研究提供一定的理论依据。从实验过程和结果看,利用粉体脉冲微喷射技术制备功能梯度材料具有结构精确、节约成本等优点。 相似文献
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在微结构动态特性的检测中引入块匹配技术和光流技术.结合微结构的运动特性,分别提出了基于块匹配技术和基于光流技术的两种微结构二维运动估计算法.利用这两种二维运动估计算法对平面微谐振器做动态特性分析,均取得了较好的测量结果.对这两种二维运动估计算法在微谐振器动态特性中的测量应用做比较,结果表明:块匹配算法适合简单的平移运动测量,计算量小,但它要求被测器件在结构上有较为特殊或显著的运动特征区域;光流算法通过分析单个像素的灰度分布特性来测量被测器件的运动特性.与块匹配法相比,它并不要求被测器件有较为特殊的运动特征结构.由于光流法以单个像素为计算单位,且其中包含有较多的差分计算,计算过程较为复杂,因此测量分析所需的时间长. 相似文献
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A. A. Starostin P. V. Skripov A. R. Altinbaev 《International Journal of Thermophysics》1999,20(3):953-963
The method of controlled pulse heating of a wire probe in good contact with a liquid has been developed for estimation of the thermophysical properties in the region of instability of this liquid with respect to the temperature and the heat flux. It ensures rapid penetration into the region of short-lived states and maintenance of a given temperature in this region. This paper presents and discusses the character of variations of the values of the thermal activity and the lifetime of a system, before its disintegration, for thermally unstable liquids, such as polymeric and microheterogeneous systems, for different heating paths. 相似文献
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随着 NC 和 CNC 技术的迅速发展和日益普及,HSM 即使用高速切削机械的加工技术已越来越受到人们的重视。HSM 不仅可以提高加工效率,降低成本,而且可以提高加工精度,改善加工质量。同时,HSM 的发展又对主轴系统、进给系统、CNC 控制系统、刀具、刀具夹持系统等各方面提出了新的要求。本文对高速切削的特点及实现高速切削加工的要求做一些具体的分析。 相似文献
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There are some suitable methods for the measurement of ultrashort solitary electromagnetic pulses (EMP) that are generated by high-power microwave generators. The characteristics of EMPs are high-power level (Pmax = 250 MW) and very short-time duration (tp euro (1, 60) ns). Special requirements for measurement methods have to be considered because of the specific EMPs properties. In this paper, two suitable methods for this application are presented. The first one, the calorimetric method, utilizes the thermal impacts of microwave absorption. The second method presented-the magnetooptic (MO) method-uses the Faraday's MO effect as a sensor principle. A combined calorimetric sensor was realized and there were some experimental EMP measurements made with good results. The sensor utilizing the MO method is still in development. 相似文献
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A. Seifter F. Sachsenhofer G. Pottlacher 《International Journal of Thermophysics》2002,23(5):1267-1280
The microsecond pulse heating system has been used for more than 15 years to investigate thermophysical properties of solid and liquid metals and alloys. The only way to measure temperature in the time and temperature range of these experiments (duration of a few tens of microseconds, temperatures up to 7000 K) is optical pyrometry. The radiance temperature can be measured very accurately. However, to obtain true temperature from radiance temperature the normal spectral emissivity at the wavelength of interest of the material under investigation has to be known. Because normal spectral emissivity measurements on pulse heated liquid metals were not possible in the past, an assumption about the behavior of the emissivity in the liquid phase had to be made, which increased the uncertainty of the temperature determination. To overcome this limitation in temperature measurement, a microsecond division of amplitude polarimeter (µ-DOAP) was added to the pulse heating system. The normal spectral emissivity at 684.5 nm is derived from the measured change in the state of polarization of laser light that is reflected off the sample surface. The working principle of this polarimeter system is presented, and experimental results of the normal spectral emissivity at 684.5 nm as a function of radiance temperature at 650 nm are discussed. 相似文献
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G. C. Bussolino G. Annino C. Ferrari F. Righini 《International Journal of Thermophysics》2011,32(11-12):2716-2726
A bi-dimensional geometrical model was developed and numerically solved considering different cylindrical tungsten specimens, heated to temperatures above 3600 K with current pulses of about (500, 750, and 950) ms duration. A detailed analysis of these virtual experiments indicated large radial temperature differences in all the investigated cases. The range of validity of the long thin rod approximation was verified for various geometries and under different experimental conditions. The developed model may be used to estimate uncertainties due to the use of this approximation and to optimize experimental conditions in real experiments. 相似文献