Abstract

In this work, a comparative study of the methods of boriding, carboboronizing, and borosiliconizing of VT-1.0 titanium is carried out in order to increase the wear resistance in aggressive environments at elevated temperatures. The microstructure of diffusion coatings is investigated, and their thickness and microhardness are determined. Diffusion saturation of VT-1.0 titanium specimens with dimensions of 10 × 10 × 25 mm was carried out from saturating mixtures based on boron carbide. Saturation mode: process temperature of 950°C, saturation time of 1.5 h. At the end of the high-temperature exposure, the samples were removed from the furnace and cooled in air to room temperature, the saturating coating was cleaned from the samples with wooden spatulas, and the samples were boiled in soap and soda solution for 1 h. A continuous diffusion layer 80–100 µm thick forms on the titanium surface. The borosilicized diffusion layer obtained by saturation of titanium from a mixture of 45% B₄C–5% Na₂B₄O₇–22% Si–5% NaF–3% NaCl–20% CrB₂ has a higher microhardness: 1520 HV_0.1 versus 1280 HV_0.1 for carboboronizing one and 1120 HV_0.1 for boriding. In this case, boriding and carboboronizing coatings obtained, respectively, by saturation from daubs of the composition 45% B₄C–5% Na₂B₄O₇–5% NaF–25% Al₂O₃–20% CrB₂ and 70% B₄C–5% Na₂B₄O₇–5% NaF–20% CrB₂ have a pronounced zonal structure. The upper zone of these coatings, having a high microhardness, also has high brittleness indicators, which does not allow accurately measuring the microhardness distribution indicators because of chipping and cracking in the places where the microhardness is measured. X‑ray diffraction studies of the qualitative composition of coatings on titanium were carried out on a DRON-6 X-ray diffractometer in filtered CuK_α radiation (λ = 1.5418 Å) in the angle range 2θ = 20°–80°. The diffusion coating exhibits reflections of titanium carbide, chromium and titanium borides, and a certain amount of Cr₂Ti intermetallic compound. Boride phases of chromium and titanium refer to high boron phases with a high specific boron content: TiB, CrB, Ti₂B₅, Ti₃B₄, and Cr₂B₃.

中文翻译：

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涂层形式的含硼活性介质的组成对钛零件扩散层结构和性能的影响

摘要

在这项工作中，对 VT-1.0 钛的渗硼、碳硼化和硼硅化方法进行了比较研究，以提高在高温腐蚀性环境中的耐磨性。研究了扩散涂层的微观结构，并确定了它们的厚度和显微硬度。从基于碳化硼的饱和混合物中进行尺寸为 10 × 10 × 25 mm 的 VT-1.0 钛样品的扩散饱和。饱和模式：工艺温度950℃，饱和时间1.5小时。在高温暴露结束时，将样品从炉中取出并在空气中冷却至室温，用木铲从样品上清除饱和涂层，并将样品在肥皂和苏打溶液中煮沸 1 h . 在钛表面上形成一个 80–100 µm 厚的连续扩散层。由 45% B 的混合物中的钛饱和得到的硼硅化扩散层₄ C–5% Na ₂ B ₄ O ₇ –22% Si–5% NaF–3% NaCl–20% CrB ₂具有更高的显微硬度：1520 HV _0.1对 1280 HV _0.1用于碳硼化 1 和 1120 HV _0.1用于硼化。在这种情况下，硼化和碳硼化涂层分别通过从 45% B ₄ C–5% Na ₂ B ₄ O ₇ –5% NaF–25% Al ₂ O ₃ –20% CrB ₂和70% B ₄ C–5% Na ₂ B ₄ O ₇ –5% NaF–20% CrB₂具有明显的带状结构。这些涂层的上层具有较高的显微硬度，脆性指标也很高，由于在测量显微硬度的地方出现碎裂和开裂，因此无法准确测量显微硬度分布指标。钛涂层定性成分的 X 射线衍射研究是在 DRON-6 X 射线衍射仪上在2θ = 20°–80° 角度范围内过滤的 Cu K _{α辐射 (λ = 1.5418 Å) 中进行的。}扩散涂层表现出碳化钛、铬和硼化钛的反射，以及一定量的Cr ₂钛金属间化合物。铬和钛的硼化物相是指具有高比硼含量的高硼相：TiB、CrB、Ti ₂ B ₅、Ti ₃ B ₄和Cr ₂ B ₃。