WEAR-RESISTANCE IN CERAMIC SILICON-NITRIDE CUTTING TOOLS BEARING CONTINUOUS OR DISCRETE TITANIUM NITRIDE COATINGS

Measurements have been made on the wear resistance of ceramic cutters based on silicon nitride and bearing titanium nitride coating during t he continuous machining of ShKh15 steel. The coatings were deposited b y cathode sputtering. Use was made of continuous coatings and discrete ones in the form of ordered fragments. The continuous TiN coatings ra ise the wear resistance by a factor of 1.7, while the factor is 2.2 fo r the discrete TiN coatings. The performance of the tool is also impro ved in the case of the discrete coatings as the cutting speed and feed can be raised by comparison with tools with continuous coating.