The directional spectral emissivities of two V-4Cr-4Ti family alloys, candidate structural materials for fusion first wall/blanket applications, were measured between 200 °C and their working temperatures (700–750 °C), with and without a high-temperature treatment. Besides showing the typical metallic behavior, an increase in the emissivity after the heat treatment (1000–1200 °C) was observed in both alloys. This has been attributed to several microstructural changes, which show the important role of microstructure in the thermal radiative properties of these alloys. In order to explain these mechanisms, the samples were analyzed using electron microscopy and X-ray diffraction. These measurements revealed differences in grain size, composition of the main phase and amount and distribution of dispersed secondary phases. X-ray diffraction and X-ray photoelectron spectroscopy were also used in order to check the extent of oxygen penetration. The results of directional spectral emissivity measurements were integrated to calculate the total hemispherical emissivity, the key heat transfer parameter in the high-temperature high-vacuum environments of fusion reactors. It is observed that the strategy of mechanical alloying with oxide and carbide dispersion to improve the mechanical properties also translates into an enhancement of the radiative refrigerating capability of these alloys.

两种V-4Cr-4Ti族合金（用于融合第一壁/毛毯应用的候选结构材料）的定向光谱发射率在200°C和其工作温度（700–750°C）之间（有和没有高温时）进行测量治疗。除了显示出典型的金属行为外，两种合金均观察到热处理（1000–1200°C）后的发射率增加。这归因于几种微观结构的变化，这些变化表明了微观结构在这些合金的热辐射性能中的重要作用。为了解释这些机制，使用电子显微镜和X射线衍射对样品进行了分析。这些测量表明晶粒尺寸，主相组成以及分散的第二相的数量和分布存在差异。为了检查氧气渗透的程度，还使用了X射线衍射和X射线光电子能谱。对定向光谱发射率的测量结果进行了综合，以计算总半球发射率，这是聚变反应堆高温高真空环境中的关键传热参数。可以看出，用氧化物和碳化物分散液机械合金化以改善机械性能的策略还转化为这些合金的辐射制冷能力的增强。聚变反应堆高温高真空环境中的关键传热参数 可以看出，用氧化物和碳化物分散液机械合金化以改善机械性能的策略还转化为这些合金的辐射制冷能力的增强。聚变反应堆高温高真空环境中的关键传热参数 可以看出，用氧化物和碳化物分散液机械合金化以改善机械性能的策略还转化为这些合金的辐射制冷能力的增强。