Hemispherical Total Emissivity of Niobium, Molybdenum, and Tungsten at High Temperatures Using a Combined Transient and Brief Steady-State Technique
Hemispherical Total Emissivity of Niobium, Molybdenum, and Tungsten at High Temperatures Using a Combined Transient and Brief Steady-State Technique
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DOI：
10.1023/a:1022699622719
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发表时间：
1999-05
影响因子：
2.2
通讯作者：
T. Matsumoto;A. Cezairliyan;D. Basak
中科院分区：
文献类型：
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作者：
T. Matsumoto;A. Cezairliyan;D. Basak
采用瞬态和短暂稳态相结合的新方法测量了铌、钼和钨三种难熔金属的半球总发射率。该技术是基于快速电阻自加热的固体圆柱形试样在真空中达到预设的高温在短时间内（约200毫秒），然后保持试样在该温度下的稳态条件下的一个短暂的时期（约500毫秒），然后切断电流通过试样。半球形总发射率在温度平台处根据关于通过样品的电流、样品中间部分的电压降和样品温度的数据使用基于Stefan-Boltzmann定律的稳态热平衡方程来确定。试样的温度是由测量的表面辐射温度和法向光谱发射率确定的;后者是由激光偏振测量获得的。报道了铌（2000 ~ 2600 K）、钼（2000 ~ 2700 K）和钨（2000 ~ 3400 K）的半球全发射率的实验结果。
The hemispherical total emissivity of three refractory metals, niobium, molybdenum, and tungsten, was measured with a new method using a combined transient and brief steady-state technique. The technique is based on rapid resistive self-heating of a solid cylindrical specimen in vacuum up to a preset high temperature in a short time (about 200 ms) and then keeping the specimen at that temperature under steady-state conditions for a brief period (about 500ms) before switching off the current through the specimen. Hemispherical total emissivity is determined at the temperature plateau from the data on current through the specimen, the voltage drop across the middle portion of the specimen, and the specimen temperature using the steady-state heat balance equation based on the Stefan–Boltzmann law. Temperature of the specimen is determined from the measured surface radiance temperature and the normal spectral emissivity; the latter is obtained from laser polarimetric measurements. Experimental results on the hemispherical total emissivity of niobium (2000 to 2600 K), molybdenum (2000 to 2700 K), and tungsten (2000 to 3400 K) are reported.