利用傅里叶红外光谱仪在温度范围为573~953 K、波长范围为3~20 μm下测量Ti-6Al-4V合金在0°~84°下的方向光谱发射率,并系统研究了方向变化对其光谱发射率的影响。实验结果表明,在波长小于10.3 μm的短波处,Ti-6Al-4V合金发射率在0°~84°下随角度变化呈现出类似绝缘体的特性,而在大于10.3 μm的长波处,其变化呈现出类似金属的特性。该合金的光谱发射率在573~773 K范围内随温度的升高而增大,并且在0°~70°与80°~84°内随波长变化趋势相反。当Ti-6Al-4V合金氧化后,其发射率在60°时达到最大值且非金属特性在长波处随氧化时间增加越来越明显。由此可见,在不同测量角度下,温度、波长和氧化程度等因素对Ti-6Al-4V发射率的影响很大,该研究可以丰富Ti-6Al-4V合金的方向光谱发射率数据库,为辐射测温技术提供数据支持。

In this paper, the directional emissivity of Ti-6Al-4V alloy at 0°--84° was measured using Fourier transform infrared spectroscopy at a temperature range of 573--953 K and a wavelength range of 3--20 μm. The influence of direction on the spectral emissivity was systematically studied. Results show that the emissivity of Ti-6Al-4V alloy is similar to that of an insulator in the angle range of 0°--84° when the measurement wavelength is less than 10.3 μm, and therefore, it is more similar to that of metal when the wavelength exceeds 10.3 μm. The emissivity increases with temperature that ranges between 573--773 K, and it is observed that the change trend of emissivity with wavelength is opposite for the angle range of 0°--70° and 80°--84°. When the Ti-6Al-4V alloy is oxidized, its emissivity is maximum at 60°, and the non-metallic properties of emissivity at long-wavelength are evident with the increasing oxidation time. Therefore, this study enriches the directional spectral emissivity database of Ti-6Al-4V alloys and provides data support for radiation temperature measurement technology.