STUDY ON WEAR MECHANISM OF COATED CARBIDE TOOLS WHILE MACHINING TITAN-31

Abstract

Titanium alloys are widely used in aerospace industry due to their attractive property of high strength to weight ratio, but they have certain unique properties which make them difficult to be machined compared to other conventional materials. Some of their inherent properties which affect the machinability are low thermal conductivity, small chip tool contact area, strong affinity to chip welding, low modulus of elasticity and high chemical reactivity during machining. These properties of the work material have posed serious problems in its machining. Most of the tool materials, as ceramics, diamond and cubic boron nitride are highly reactive with titanium alloys and consequently are not used to machine these alloys. However, coated carbide tools are said to reduce the cutting forces and improve wear resistance. ecently; WIDALON; a multicoated tool,-has been - deer-e-1-©ped- by WIDIA.-In-this-work,_the._wear_mechanism and performance of h s =tools in~nachin-ing--.TITAN-31- (Ti_-6A3 . +V)=have been _studied— The results show that for the conditions investigated the principal wear mechanism of WIDALON T(15 leading to flank and crater wear is attrition. Grooving and chip notching are absent. Uncoated carbide tool TTX fails mainly because of plastic deformation of cutting edge. WIDALON TK15 can be used effectively at higher cutting speeds (60-110 m.min 1). TiC-coated insert TG gives always poor performance than TK15. The uncoated carbide insert T'I'X shows good performance at low cutting speeds only (40 m.min-1) but fails because of plastic deformation at 60 m.min.