Abstract Chemical vapor deposition (CVD) process is an effective way to fabricate highly pure ultra-fine powders; however commercial fabrication of high quality TiC powders through conventional CVD (TiCl4–H2–CH4) system remains a great challenge. The main obstacle is that the conversion of chemically stable TiCl4 to TiC is too low (theoretically 13.3% at 1000 °C) to provide sufficient supersaturation to form powders but only coating. To tackle this problem, relatively unstable TiCl3 was proposed as a novel precursor, which is easier to achieve homogeneous nucleation due to the higher conversion of TiCl3 to TiC in the TiCl3–CH4–H2 system (theoretically 37.7% at 1000 °C). In addition, a fluidized bed reactor (FBR) with fluidized TiC seeds providing local turbulence was employed to boost the homogeneous nucleation. Based on the novel idea, for the first time, high purity nano-sized TiC powders (about 77.1 nm, purity 99.46 at.%) were successfully fabricated by a fluidized bed chemical vapor deposition (FBCVD) process. More importantly, an advanced simple and effective process was successfully developed to activate the common TiCl4 raw material to synthesize nano-sized TiC powders by designing the reactor.

中文翻译：

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流化床反应器化学气相沉积系统合成纳米TiC粉末

摘要 化学气相沉积（CVD）工艺是制备高纯度超细粉末的有效途径；然而，通过传统的 CVD (TiCl4–H2–CH4) 系统商业化制造高质量的 TiC 粉末仍然是一个巨大的挑战。主要障碍是化学稳定的 TiCl4 转化为 TiC 的转化率太低（在 1000 °C 时理论上为 13.3%），无法提供足够的过饱和度以形成粉末而仅形成涂层。为了解决这个问题，相对不稳定的 TiCl3 被提出作为一种新的前驱体，由于在 TiCl3-CH4-H2 体系中 TiCl3 向 TiC 的转化率更高（理论上在 1000°C 时为 37.7%），它更容易实现均匀成核。此外，采用流化床反应器 (FBR) 和流化 TiC 晶种提供局部湍流来促进均匀成核。基于新颖的想法，首次通过流化床化学气相沉积（FBCVD）工艺成功制备了高纯度纳米级 TiC 粉末（约 77.1 nm，纯度 99.46 at.%）。更重要的是，通过设计反应器，成功开发了一种先进的简单有效的工艺，将常见的TiCl4原料活化合成纳米级TiC粉末。