| 摘要 |
<p>According to the present invention there is provided a body coated with refractory single- or multilayers, wherein specific layers are characterized by a controlled microstructure and phase composition with crystal planes preferably grown in a preferential direction with respect to the surface of the coated body. Said coating comprises one or several refractory layers of which at least one layer is a dense, fine-grained layer of α-Al2O3 textured in the (104) direction. The Al2O3-coating is obtained by control of the oxidation potential of the CVD-reactor atmosphere prior to the nucleation of Al2O3, which is initiated by a controlled sequencing of the reactant gases. During the growth of the Al2O3 a sulphur dopant is added, preferably H2S. The coated tool according to the invention exhibits excellent surface finish and shows much improved wear and toughness properties compared to prior art objects when used for machining steel, cast iron and, particularly, when machining nodular cast iron.</p> |
