In-situ SiC reinforced Si-SiC 3D skeletons in SiC/Al-Si composites

For Al-Si alloys, the three-dimensional (3D) network structure of Si plays a key role on their mechanical properties. In order to improve the microstructure and elevate the strength of the network, in-situ SiC was introduced into Al-Si alloys and four kinds of composites and their Si-SiC 3D skeletons were obtained. The microstructures especially the interfacial characteristics were studied in detail. Due to the heterogeneous nucleation role of in-situ SiC, effective interface was formed between in-situ SiC and Si. Moreover, in-situ SiC can grow epitaxially at the surface of external SiC and form a stable Si/SiCin/SiCex sandwich structure with in-situ SiC as the interlayer. As a result, the Si-SiC 3D skeletons became more intact and stable, and their compressive strength was remarkably elevated. (C) 2019 Elsevier B.V. All rights reserved.