ALUMINA WOVEN FIBRE-REINFORCED COMPOSITES PRODUCED BY DIRECTED MELT OXIDATION

摘要

Two-dimensional woven Al_2O_3 fibre-reinforced Al_2O_3/Al matrix composites have been produced by directed melt oxidation of Al-Mg alloys. In order to prevent chemical interaction between the fibre and matrix during processing, barrier coatings on the fibres are necessary. In this work, the process of depositing multilayer coatings on the Al_2O_3 woven fibre was investigated. The first deposited layer was ZrO_2 which acted as a reaction barrier and interface debond coating; a further coating of protective aluminia overlayed the ZrO_2 layer to match to the Al_2O_3 matrix during directed melt oxidation process; finally silica was deposited as an outer layer as an initiator for the directed oxidation reaction. This study primarily concentrated on the deposition techniques and the resultant microstructure of the interlayers to evaluate the feasibility of using these methods in the development of all oxide CMCs' by the directed melt oxidation process.