Oxide coated cutting tool

摘要

According to the present invention there is provided a body at least partially coated with one or more refractory layers of which at least one layer essentially consist of alpha-Al2O3. Said alpha-Al2O3 layer consists of essentially equiaxed grains with an average grain size of <1 mum and with a bimodal grain size distribution with coarser grains with an average grainsize in the interval 0.5-1 mum and finer grains with an average grainsize of <0.5 mum. The Al2O3 layer further contains striated zones containing titanium (>5 at %) but no nitrogen or carbon. This particular microstructure is obtained by temporarily stopping the gases needed for the growth of the Al2O3 layer and introducing TiCl4.