Performance of PVD AlTiCrN coating during machining of austenitic stainless steel

Abstract

In this study, the experimental results of dry, high speed turning of AISI 304 austenitic stainless steels using nanocrystalline AlTiCrN coated cemented carbide insert are presented. High power pulsed magnetron sputtering (HPPMS) and cathodic arc evaporation (CAE) techniques were used to deposit nanocrystalline AlTiCrN coating on fine grained K grade cemented carbide insert. The composition and microstructure of the deposited nanocrystalline AlTiCrN coatings were analysed using SEM. In addition, the adhesion and microhardness of the coatings were evaluated. Fine grained appearance with dense columnar structure was observed for the coating deposited by HPPMS technique. Microhardness values for nanocrystalline AlTiCrN coating deposited by HPPMS and CAE techniques were found to be 35 and 37 GPa respectively for the thickness of 4·2 μm. The effect of cutting speed and feed on the tool wear was investigated. HPPMS coated tool exhibited tool life of 24 min, whereas CAE coated tool exhibited tool life of 15 min for the same conditions.

Keywords:

• HPPMS
• CAE
• AlTiCrN
• Machining
• SS 304
• Tool life

The authors gratefully acknowledge the funding support that was received from the Department of Science and Technology, Government of India, under DST-FAST TRACK programme for young scientist (sanction no. SR/FTP/ETA-68/2009 dated 21 April 2010). The authors are also thankful to the CemeCon AG, Germany, and IonBond, India, for the coating support.