Study of the Coating-Substrate Interface Layer an A1_2O_3-Coated Cemented Carbide Cutting Tool

摘要

The microstructure of the interface bonding zone of the Al_2O_3 coating and the cemented carbide substrate of a coated tool has been analyzed using transmission electron microscopy. It is concluded that a complex aluminium-tantalum oxide of rutile type AlTaO_4 contributes to the strong bonding owing to the similarity of its crystal structure to TiO_2. Synthesis of experimental tools with other oxides very similar to AlTaO_4 as bonding material confirmed this hypothesis.