| abstract |
The present invention introduces a new, precise method for producing an α-Al 2 O 3 layer having substantially better wear resistance and toughness than the prior art. The α-Al 2 O 3 layer of the present invention is formed on a bonding layer of (Ti, Al) (C, O, N) having an aluminum content which is increased toward the skin surface. Nucleation of α-Al 2 O 3 is achieved by a nucleation step comprising both an aluminising and an oxidation step. Α-Al 2 O 3 layer according to the present invention has a thickness in the range of 1 to 20㎛ and consists of columnar particles. The length / width ratio of the alumina particles is 2 to 12, preferably 5 to 9. The layer is characterized by strong (012) growth tissue, as measured by XRD, and also characterized by almost total (104), (110), (113) and (116) diffraction peaks. |