Investigation of Cryogenically Treated Physical Vapor Deposition TiAlN/NbN-Coated Carbide Inserts in End Milling of Hard Titanium Alloy

Abstract Cryogenic-treated inserts (CTIs) are playing a vital role in the significant improvement of tool life and the enhancement of mechanical properties of the cutting tools during conventional machining process. This work addressed the upshot of cryogenic treatment of physical vapor deposition TiAlN/NbN-coated carbide insert on the machinability of a Ti-6Al-4V alloy workpiece. It is weighed in terms of surface roughness, chip morphology, and tool wear in the cutting tool insert. Surface roughness was measured by a noncontact type 3-D laser scan microscope system. The observed average surface roughness in CTI reduction is between 13 and 32 % over that of the untreated insert (UTI) machining condition. The multisurface chip characteristics of free surface and back surface were identified and broken down by scanning electron microscopy. The experimental results demonstrated that the favorable chips and the reduction in tool wear were better achieved under the CTI machining condition than under the UTI machining condition.