The structure and phase composition of Fe–Ti–Ni–C alloys produced in situ by thermal synthesis at 1200°C using TiH2, Fe, graphite, and Ni powder mixtures have been studied. The synthesized alloys represent a skeleton of titanium carbide grains of different stoichiometry, with sizes varying from 0.5 to 16 μm, surrounded by metal reinforcement layers. The starting mixtures without nickel or with 5% Ni have coarse TiC grains. When Ni content of the mixture increases to 10–20%, the maximum grain size sharply decreases to 6–7 μm. The microhardness of the synthesized alloys decreases when nickel amount in the mixture increases to 15% but becomes somewhat higher at 20% Ni. The phase composition of the alloys substantially depends on the amounts of starting mixture components and includes titanium carbide, Fe3C cementite, α-iron solid solution, and intermetallic FeNi3 (for ironcontaining mixtures) and Ni3Ti and Ni4Ti (for nickel-containing mixtures). When Ni content of the starting mixture increases to 10–20%, the lattice parameter and stoichiometry of TiCx slightly decrease and carbide particles noticeably refine. The thermally synthesized alloys have been ground to produce reinforced steel composite powders, which can find extensive application in depositing wear-resistant coatings and fabricating bulky parts by compaction followed by sintering, hot pressing, or hot forging.

中文翻译：

---

Fe-Ti-Ni-C合金在热合成中获得的结构和相组成

已经研究了使用 TiH2、Fe、石墨和 Ni 粉末混合物在 1200°C 下通过热合成原位生产的 Fe-Ti-Ni-C 合金的结构和相组成。合成的合金代表不同化学计量的碳化钛晶粒骨架，尺寸从 0.5 到 16 μm 不等，被金属增强层包围。不含镍或含 5% Ni 的起始混合物具有粗大的 TiC 晶粒。当混合物的 Ni 含量增加到 10-20% 时，最大晶粒尺寸急剧减小到 6-7 μm。当混合物中的镍含量增加到 15% 时，合成合金的显微硬度会降低，但在 20% 的镍时会有所提高。合金的相组成主要取决于起始混合物组分的量，包括碳化钛、Fe3C 渗碳体、α-铁固溶体、和金属间化合物 FeNi3（用于含铁混合物）和 Ni3Ti 和 Ni4Ti（用于含镍混合物）。当起始混合物的 Ni 含量增加到 10-20% 时，TiCx 的晶格参数和化学计量略有下降，碳化物颗粒显着细化。热合成合金已被研磨以生产增强钢复合粉末，可广泛应用于沉积耐磨涂层和通过压实、烧结、热压或热锻制造大件零件。