In-situ Reaction Synthesis of Structural Ceramic Nanocomposites
纳米复相结构陶瓷的原位反应合成

The principle and feasibility of in-situ reaction synthesis process for the preparation of structural ceramic nanocomposites is briefly introduced. It is considered that the in-situ reaction synthesis process is an effective method for the preparation of structural ceramic nanocomposites. Meanwhile, the features and ways for property improvement of h-BN composites are discussed. It is suggested that high performance BN composites are difficult to be produced by conversional process. In this work, a series of in-situ chemical reactions are proposed, fine and homogeneously distributed nonoxide-boron nitride (Nobn) composites were obtained by hot pressing or pressureless sintering. The in-situ formed nanosized BN flakes were distributed at the grain boundaries of the SiC matrix. A new concept of composites called Partially Weakened Interfaces Composites (PWIC) is suggested and a PWIC is obtained in this SiC-BN composite when the BN content is less than a certain value. Such PWICs demonstrate excellent comprehensive mechanical properties.