Patent ID: 8025991

Claim:
A cutting tool comprising a base body, which supports a layer system comprising at least one mono-phase metastable at least ternary oxide layer, wherein the at least one mono-phased metastable at least ternary oxide layer is produced using a physical vapor deposition process (PVD), wherein the at least one mono-phased metastable at least ternary oxide layer is a substitution mixed crystal, wherein the at least one mono-phased metastable at least ternary oxide layer includes a main component and at least one minor component, wherein the main component forms a predominant proportion and the at least one minor component forms a smaller proportion of more than 1 atomic percent and up to 4 atomic percent, wherein the main component is aluminum and the at least one minor component is chromium, titanium, or zirconium, and wherein the at least one mono-phased metastable at least one ternary oxide layer has the structure of a γ-aluminum oxide layer.