First-of-a-kind endeavour exploiting the effects of nanoparticles on the performance and emission spectra of biodiesel derived from waste cooking oil.

Super-duplex stainless steel (SDSS) is a class of materials that possess excellent mechanical properties with enhanced corrosion resistance. Given the presence of several alloying elements and the existence of a two-phase microstructure, it can be argued that it is one of the few materials that are difficult to machine. Therefore, the present study attempts to establish an improved understanding of the state-of-the-art development in insert coatings capable of providing excellent tribological and thermal resistance properties. In this work, monolayers of AlTiN and AlCrN are PVD coated on commercial carbide inserts so as to compare and contrast the performance of nitride coatings in the dry turning of SDSS. This study evaluates the machining performance in terms of tool wear, chip characteristics, tool life and surface finish. The coated surfaces were observed through optical microscope, profilometers, scanning electron microscope and energydispersive X-ray spectroscopy to evaluate the morphological changes. The results of the work indicate that machining with PVD-coated AlTiN insert showed longer tool life, better surface finish and smaller chip thickness when compared to AlCrN-coated and uncoated inserts at low to moderate cutting speeds. The dominant wear mechanism was found to be adhesion, where during turning long continuous chips were formed for uncoated inserts and small segmented chips were formed for coated inserts at different machining parameters. Contrarily, the study also purportedly explores the improved performance of AlCrN-coated inserts over AlTiN-coated inserts at high cutting speed.