This work characterized the surface-modified layers generated on a titanium alloy during gas blow induction heating (GBIH), so as to elucidate the rapid nitriding mechanism. The surface microstructures of GBIH nitrided specimens were analyzed by X-ray diffraction, micro-Vickers hardness testing, scanning electron microscopy and X-ray photoelectron spectroscopy. The data indicate that applying this process for only several minutes can forms nitrided layers on Ti-6Al-4V alloy surfaces, the characteristics of which are similar to those of layers produced by ordinary gas nitriding for several hours. The temperature inside the material was determined to be higher than that on the surface during GBIH nitriding. However, the thickness of the nitrided layer exceeded the estimated value based on the diffusion coefficient at this high internal temperature. This especially thick nitrided layer can possibly be attributed to eddy currents generated in the metal by the application of a high-frequency current. Passivation films on the surface of the Ti-6Al-4V alloy were found to be removed during GBIH nitriding, which is ascribed to the diffusion of oxygen atoms in the passivation film into the substrate. Thus, the data show that GBIH nitriding is able to modify a Ti-6Al-4V alloy within a short period of time based on the effect of an eddy current and the disappearance of the passivation film.

这项工作的特点是在吹气感应加热（GBIH）期间在钛合金上产生的表面改性层，以阐明快速氮化机理。通过X射线衍射，显微维氏硬度测试，扫描电子显微镜和X射线光电子能谱分析了GBIH氮化试样的表面微观结构。数据表明仅应用该过程几分钟即可在Ti-6Al-4V合金表面上形成氮化层，其特性与普通气体氮化数小时后产生的层相似。在GBIH氮化过程中，确定材料内部的温度高于表面温度。但是，在该较高的内部温度下，氮化层的厚度超过了基于扩散系数的估计值。这种特别厚的氮化层可能归因于通过施加高频电流在金属中产生的涡电流。发现在GBIH氮化过程中去除了Ti-6Al-4V合金表面的钝化膜，这归因于钝化膜中的氧原子扩散到基底中。因此，数据表明，GBIH氮化能够基于涡流和钝化膜消失的作用，在短时间内对Ti-6Al-4V合金进行改性。这归因于钝化膜中的氧原子扩散到基底中。因此，数据表明，GBIH氮化能够基于涡流和钝化膜消失的作用，在短时间内对Ti-6Al-4V合金进行改性。这归因于钝化膜中的氧原子扩散到基板中。因此，数据表明，GBIH氮化能够基于涡流和钝化膜消失的作用，在短时间内对Ti-6Al-4V合金进行改性。