Resumen

SOUZA, José Vitor Candido et al. Si₃N₄ ceramic cutting tool sintered with CeO₂ and Al₂O₃ additives with AlCrN coating. Mat. Res. [online]. 2011, vol.14, n.4, pp. 514-518.  Epub 01-Nov-2011. ISSN 1516-1439.  http://dx.doi.org/10.1590/S1516-14392011005000077.

Ceramic cutting tools are showing a growing market perspective in terms of application on machining operations due to their high hardness, wear resistance, and machining without a cutting fluid, therefore are good candidates for cast iron and Nickel superalloys machining. The objective of the present paper was the development of Si₃N₄ based ceramic cutting insert, characterization of its physical and mechanical properties, and subsequent coating with AlCrN using a PVD method. The characterization of the coating was made using an optical profiler, XRD, AFM and microhardness tester. The results showed that the tool presented a fracture toughness of 6.43 MPa.m^1/2 and hardness of 16 GPa. The hardness reached 31 GPa after coating. The machining tests showed a decrease on workpiece roughness when machining with coated insert, in comparison with the uncoated cutting tool. Probably this fact is related to hardness, roughness and topography of AlCrN.

Palabras llave : AlCrN; ceramic cutting tool; mechanical properties; coating.