【摘要】 研究了Na₂B₄O₇-SiC型共渗剂中添加铁粉、铁丝和扎铁丝方式对TC4钛合金表面盐浴硼氧共渗的影响。采用金相显微镜（OM）、扫描电子显微镜（SEM）及其配备的能谱仪（EDS）、X射线衍射仪（XRD）以及显微硬度计,分析了共渗层表面形貌、物相组成和表面硬度;采用化学热力学分析讨论了铁粉型和铁丝型共渗剂无明显催渗作用的原因,采用电化学模型解释了扎铁丝对盐浴硼氧共渗的催渗机理。结果表明,各组共渗层具有较好的表面形貌,组织均匀;渗层主要由TiB、TiB₁₂、Ti₂B₅和TiB₂₅等钛硼化合物以及TiO₂和TiC相组成;硼砂—碳化硅型、铁粉型和铁丝型共渗层表面硬度依次为677、673和680 HV,性能相似;而扎铁丝型共渗剂中形成电化学效应,具有更好的表面质量,主要由TiB、TiB₁₂、TiC和Al₂O₃相组成,更高的表面硬度（989 HV）,比TC4钛合金基体硬度提高了2.75倍,比碳化硅型表面硬度提高了46.04%。更多还原

【Abstract】 Effects of the addition of iron powder,iron wire and tying iron wire on samples in Na₂B₄O₇-SiC salt bath on oxygen-boronizing of TC4 titanium alloy were investigated.Microstructure,phases and micro-hardness of the oxygen-boronized layer were examined by optical microscope（ OM）,scanning electron microscopy（ SEM） with energy dispersive spectrometer（ EDS）,X-ray diffraction（ XRD） and microhardness test,respectively.No obvious catalyzing effect of the addition of the iron powder and iron wire in the salt bath was observed and analyzed using chemical thermodynamics.The significant catalysis of tying iron wire on samples in the salt bath was obtained and explained using electrochemical model.The results show that the oxygen-boronized layers present good surface morphology and uniform microstructure,which consists of TiB,TiB₁₂,Ti₂B₅,TiB₂₅,TiO₂ and TiC phases.The surface micro hardness of the oxygen-boronized layer prepared by Na₂B₄O₇-SiC agent with iron powder and iron wire is 677.4,672.5 and 680 HV.The electrochemical reaction occurs for the addition of iron by tying iron wire on samples and the microstructure of the boronized layer is refined,which is mainly composed of TiB,TiB₁₂,TiC and Al₂O₃,with the surface micro-hardness of 989.3 HV,which increase by 46.04% than that of the Na₂B₄O₇-Si C oxygen-boronized layer.更多还原