Fabrication of Al/Al_3Ni Matrix Composites with a Low Coefficient of Thermal Expansion

摘要

The present work describes the fabrication of PM aluminium based 20 and 56 v/100SiC composites with a 25 wt/100 Ni powder addition to the Al matrix to promote in situ formation of the intermetallic Al_3Ni. For the higher loaded composite, the Ni addition was also alternatively obtained using Ni-coated SiC particles. The expected benefits from the formed Al_3Ni were to obtain a low Coefficient of Thermal Expansion (CTE) with a SiC content low enough for adequate powder metallurgy processing and to have the densification facilitated by the transient liquid phase formed due to the heat released by the exothermal reaction between Al and Ni.