纯钛的熔盐渗硼

Molten Salt Boronizing of Pure Titanium

采用熔盐法(Na_2B_4O_7)对钛(TA2)表面进行渗硼实验。通过扫描电镜(SEM)、能谱(EDS)、X射线衍射(XRD)、显微硬度测试等分析手段,研究TA2渗硼后的物相组成、组织形貌、显微硬度。结果表明:渗层由外表层的TiB——2和内表层晶须状的TiB组成。XRD分析表明,渗硼后钛试样表面生成硼钛化合物,随保温时间的延长,TiB峰位变强。EDS分析得出,B原子扩散后,被基体钛吸附,形成过渡层,导致过渡层中的Ti含量减少,而B含量明显升高。渗硼层显微硬度由外层至内层逐渐减小,变化范围约为23000MPa～7500MPa,高于TA2基体的硬度。

Molten salt horonizing experiment was carried out on a titanium plate （TA2） surface. Phase composition, microstructure and micro-hardness were characterized by means of scanning electron microscope （SEM）, energy dispersive spectrometer （EDS） and X-ray diffraction （XRD）. The results show that the boronizing layers are composed of outer thin TiB2 surface and inner TiB surface. The analysis of XRD patterns reveals that the B-Ti compounds are formed after boronizing. With the increase of B diffusion time, the peak intensity of TiB increase. The analysis of EDS indicates that B atoms are absorbed by titanium substrate, resulting in the Ti content decrease and the B content increase significantly over the horonizing layer. The micro-hardness of the horonizing layer, which is higher than TA2 matrix, decreases from the outer to the inner layer ranging from 7500MPa to 23000MPa.