C在铝熔体中极低的溶解度使原位生成SiC极其困难，国内外还未提出简便有效的原位生成SiCp/Al复合材料制备工艺。本项目提出了一种通过主导原子（Si、Al等）掺杂碳质粒（固体含碳物）诱导其结构演变与渐进式反应来制备该复合材料的新方法，并以碳质粒在铝熔体中的结构演变规律与原位反应过程为研究对象，借助液态金属X射线衍射仪等系列结构分析手段深入系统地研究铝熔体原位生成SiC的渐进式反应机制。研究碳质粒种类、铝熔体状态及工艺参数对该反应过程的影响规律，分析其反应热力学和临界反应条件；研究碳质粒中原子掺杂与迁移以及结构演变规律，探明渐进反应过程中碳质粒、过渡相与SiC间的结构相关性；建立液-固原位反应生成SiC等物相的"原子掺杂→结构演变→原位生成"普适性渐进式反应模型；掌握SiC在铝熔体中的生长规律、原子掺杂及其调控技术，为研制高强耐热抗疲劳SiCp/Al复合材料提供科学依据。

It is really difficult to produce SiC by in-situ synthesis method due to the extremely low solubility of C atoms in aluminum melt. Up to now, there is no report about the feasible technology for the in-situ synthesis of SiCp/Al composites. Based on the structural evolution and gradual reaction principle induced by doping carbon-bearing particles with dominant atoms (such as Al and Si, etal), a novel method to synthesize the in-situ SiCp reinforced aluminum matrix composites is proposed in the project. The structural evolution rule of the carbon-bearing particles and the subsequent gradual reaction process in Al melt are the main research objects, and the gradual reaction mechanisms of the in-situ synthesizing SiC particles in such situation will be systematically studied using a series of structural analysis means, such as the Liquid Metal X-ray Diffractometer (LMXRD) and so on. The influences of varietes of carbon-bearing particles, the Al melt state and technological parameters on the reaction process will be studied and then the reaction thermodynamics and the critical reaction conditions will be analyzed. The atom doping and migrating, the structural evolution mechanism in a carbon-bearing particle, and the structural correlation among carbon-bearing particles, transient phases and SiC particles will be revealed. It is an important aim of the project to establish a gradual reaction model of "atom doping→structural evolution→in-situ reaction", which is wide applicable to the synthesis of other compounds. The growth mechanism, atom doping and controlling technique of SiC in the Al melt will be mastered, which will provide key scientific basis for the preparation of SiCp/Al composites with high strength, excellent heat and fatigue resistant properties.