APPLICATION OF DIAMOND-COATED CUTTING TOOLS

Today, diamond-coated cutting tools are used primarily for machining n on-ferrous materials such as aluminium-silicon alloys, copper alloys, fibre-reinforced polymers, green ceramics and graphite. The tool life of cemented carbide cutting tools is greatly improved by diamond coati ng, and typically more than 10 times the tool life is obtained. In thi s report we will present cutting performances of diamond-coated insert s, twist drills, square end mills and ball nose end mills. Diamond fil ms are usually deposited more than 10 mu m thick to make tool life lon ger, since tool life is directly related to him thickness. However, in creased film thickness caused many problems with cutting performance. The most severe problem was the decrease in the transverse rupture str ength of the diamond-coated substrates. Because of this effect, the di amond-coated insert used under high speed and intermittent cutting con ditions was supposed to suffer chipping easily.