Performance Assessment of Coated Cemented Carbide Tools in Turning AISI 1018 Steel

• Main Author: Nouilati, Mohamad
• Other Authors: Efstathios I. Meletis
• Format: Others
• Language: en
• Published: LSU 2004
• Subjects: Industrial & Manufacturing Systems Engineering
• Online Access: http://etd.lsu.edu/docs/available/etd-04142004-073338/

In this study, the machining performance of a series of commercially available coated tungsten based cemented carbides, with 55o diamond shape, were investigated during finish turning of AISI 1018 steel under dry conditions. The inserts tested had a coating of TiN, Al2O3, TiN/Al2O3 and TiC/Al2O3/TiN respectively. For comparison, uncoated cemented tungsten carbide was also tested under the same cutting conditions. The coated tools exhibited superior wear resistance over the uncoated tool. The TiC/Al2O3/TiN coated tool had the lowest flank wear due to the high abrasive resistance of the TiC layer. The Al2O3 coated tool showed superior wear-resistance over the TiN/Al2O3 coated tool due to the TiN coating that deteriorated the effect of the Al2O3 outer layer. The TiN coated tool showed the least wear resistance with respect to the other coated tools. Surface roughness appeared to increase with flank wear while oscillating for all the tested tools except for the TiN coated tool. The TiN coated tool produced a relatively consistent surface roughness that was not significantly affected by the flank wear under the conditions tested. The coated tools produced lower surface roughness compared to the uncoated tool, except for the TiN/Al2O3 coated tool, which produced considerably higher surface roughness. The reason for this however was the geometry of the chip breaker, rather than the coating materials, which produced longer chips that came in contact with the work piece during the machining process. The TiC/Al2O3/TiN coated tool produced the lowest surface roughness of all the tools tested.