| 摘要 |
A cutting tool insert for turning of hardened steels and tool steels includes a textured CVD α-Al2O3 coated cemented carbide body. The cemented carbide body has 4.0-7.0 wt-% Co and 0.25-0.50 wt-% Cr and an S-value of 0.68-0.88 and a coercivity (Hc) of 28-38 kA/m. The α-Al2O3 layer has a thickness ranging from 7 to 12 μm, is composed of columnar grains having a length/width ratio from 2 to 12 and is deposited on an MTCVD Ti(C,N) layer having a thickness from 4 to 12 μm. The alumina layer is characterised by a pronounced (006) growth texture. |
