Desempeño de insertos de WC recubiertos con nanomulticapas de [TiN/TiAlN]^sub n^ en el mecanizado del acero endurecido AISI 4340/Performance of WC- inserts coated with nanometric [TiN/TiAlN]^sub n^- multilayer for the cutting processing of hardened AISI 4340 steel

In this paper, wear resistance of 4 μm uncoated tungsten carbide inserts (WC) and coated with (TiN/TiAlN)n multinanolayered or with commercial TiCN-Al2O3-TiN monolayers (TINAL) are examined. Life tests, cutting area temperature analysis, surface roughness measurements on work pieces, roughness measurements on the attacked surface, contact track analysis between chip-insert and chemical composition analysis were carried out. Mechanical tests were conducted on AISI 4340 steel parts using cutting regime and applying high speed cutting. The machining results showed that for a distance of 8,000 m the inserts coated with 300 bilayers exhibited wear values of 0.117 mm, inserts coated with 200 bilayers showed values of 0.138 mm and those coated with TINAL presented wear values of 0.174 mm. Moreover, the temperature values for cutting speed at 176.6 m/mim for 300 bilayers was 522.6°C, for 200 bilayers was 721.4 °C and 1,327.6°C for inserts coated with TINAL. Lower temperatures, caused by a lower friction coefficient and cutting force, contribute to life-time increasing at WC inserts.