Characterization and experimental evaluation of PVD AlTiN and TiN/TiAlN coatings for dry turning of DSS2205

DSS are more suitable alternatives for the applications requiring vehement resistance to corrosion in severe conditions and to stress corrosion cracking. Work hardening tendency, high toughness, design strength and built-up layer (BUL) formation contribute to machining difficulty of duplex stainless steel (DSS2205). The present investigations are aimed to detail machining performance in terms of tool wear, tool life and cutting temperatures. Comparison of performance of AlTiN coating using two advanced PVD coating deposition techniques, viz. HiPIMS and S3p, with multilayer TiN/TiAlN coating is studied. The coating deposition processes using S3p technique were carried out in a vacuum chamber at a pressure of 1.33 × 10 –2 Pa to 1.33 × 10 –8 Pa. AlTiN-coated tool deposited using S3p technique proved better, exhibiting the highest tool life of 7105 mm, three times more than uncoated tools, and ahead of AlTiN-coated tool deposited by HiPIMS technique (5390 mm). Among the coated tools, TiN/AlTiN-coated tools showed the highest rate of rise in cutting temperatures as 14 and 21%, for rise in cutting speeds from 100 to 140 m/min and from 140 to 180 m/min, respectively. Experimental results of cutting temperatures are found in close agreement with results of Boothroyd model within an error of ± 10%. Graphical abstract