激光熔覆原位合成TiC/Al复合材料的化学反应机制

Chemical Reaction Mechanism of In-situ Synthesis of TiC/Al Composite by Laser Cladding Process

通过突然停止激光发射的实验方法,研究了经高能球磨活化的Al、Ti和C粉末在激光熔覆条件下TiC合成反应的过程及规律。结果表明:激光辐射的前沿区的组织可以被分为未反应原始粉末区、合成反应过渡组织区及TiC/Al复合材料区。依据组织及结构的分析,活化粉末在激光条件下的合成反应过程及机制得以揭示:原始粉末首先在过渡区发生了3Al+Ti→Al3Ti反应,所有的Ti都参与了这一反应,形成了块状的Al3Ti/Al组织,所有的C元素都包裹在了这种块状的组织中;随后发生了Al3Ti+C→TiC+3Al反应而形成TiCp/Al复合材料。

With suddenly shutting off laser beam in cladding process, the TiC synthesis mechanism of Al,Ti,C powder with laser cladding was discussed. The experimental results show that the microstructure with ahead of laser irradiation region can be divided into unreacted region, transitional region and TiCp/Al composite region. Through the analysis on the microstructure, the synthesis procedure of activated Al, Ti, C powder is confirmed in condition of laser effecting. The reaction of 3 Al+ Ti → Al3Ti occurs in transitional region at first, then the reaction of Al3Ti+ C → TiC+3Al happens to form TiCp/Al composite. 