Fracture-resistant ultralloys for space-power applications: Normal-spectral-emissivity and electron-emission studies of tungsten, rhenium, hafnium-carbide alloys at elevated temperatures
Fracture-resistant ultralloys for space-power applications: Normal-spectral-emissivity and electron-emission studies of tungsten, rhenium, hafnium-carbide alloys at elevated temperatures
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用于空间能源应用的抗断裂超合金：钨、铼、碳化铪合金在高温下的法向光谱发射率和电子发射研究
DOI：
10.1016/0013-7944(90)90133-2
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发表时间：
1990
影响因子：
5.4
通讯作者：
James F. Morris
中科院分区：
文献类型：
--
作者：
B. Tsao;D. Tang;D. Jacobson;James F. Morris
在这篇论文之前，该杂志上有一系列关于“用于空间动力系统的耐断裂超合金”的高温性能：之前的出版物涵盖了含和不含钍（tho2）的钨(W)、铼（Re）合金（W, 23Re； W, 27Re； W， 30Re和W， 30Re, 1tho2）。本文报道了碳化铪（HfC）的辐射和热离子效应以及W合金中稀土的变化：法向光谱发射率（λ）在高温法中用于确定表面的真实温度。有效功函数（φ e）是空间功率应用中高温热电子能量转换器电极材料选择的重要考虑因素。在1700 ~ 2500k范围内，测量了5 ~ 20% Re的W， Re， 0.35 HfC的ε 0.535 μ, ε 0.65 μ和φ e趋势。结果表明，随着温度的升高和稀土含量的增加，λ减小。与W、Re合金含量相当的烧结材料相比，HfC的存在产生了更高的λ值。结果还表明，φ e随铼含量的增加而增大。这可以解释为与体积效应相关的金属真空边界势垒的增长- W的晶格常数的减小。
A series in this journal on high-temperature properties of “fracture-resistant ultralloys for space-power systems” preceded the present paper: the antecedent publications covered tungsten (W), rhenium (Re) alloys with and without thoria (ThO 2)(W, 23Re; W, 27Re; W, 30Re and W, 30Re, 1ThO 2). This paper reports radiative and thermionic effects of hafnium carbide (HfC) and Re variation in W alloys: normal spectral emissivity (ϵ λ) is used in pyrometry to determine the true temperature of a surface. Effective work function (φ e) is an important consideration in the selection of the electrode materials for high-temperature thermionic energy converters in space-power applications. The ε 0.535 μ, ϵ 0.65 μ and φ e trends of W, Re, 0.35 HfC with 5–20% Re were measured in the range of 1700–2500K. The results indicate that ϵ λ decreases with increasing temperatures and Re contents. The presence of HfC produced higher ϵ λ values than those of sintered materials with comparable W, Re alloy contents. The results also indicate that φ e increases with rhenium contents. This can be explained as growth of the potential barrier at the metal, vacuum boundary associated with a volume effect—the decrease in the lattice constant of W.
DOI：
--
发表时间：
2007
期刊：
影响因子：
--
作者：
A.I.Volokitin;B.N.J.Perssion;H.Ueba;H. Ueba;H. Ueba;H. Ueba
通讯作者：
H. Ueba