Tool Wear Performance of CVD-Insert during Machining of Ti-6%Al-4%V ELI at High Cutting Speed

Abstract

Machining of titanium alloys as aerospace material that has extremely strength to weight ratio and resistant to corrosion at high-elevated temperature, become more interested topic. However, titanium alloys have low thermal conductivity, relative low modulus elasticity and high chemical reactivity with many cutting tool materials. The turning parameters evaluated are cutting speed (55, 75, 95 m/min), feed rate (0.15, 0.25, 0.35 mm/rev), depth of cut (0.10, 0.15, 0.20 mm) and tool grade of CVD carbide tool. The results that pattern of tool life progression is rapidly increase at the initial stage. It was due to small contact area between the cutting tool and the workpiece. At the first step of machining, the chip welded at the cutting edge but some chip removed away from the cutting edge. Wear mechanism produced are abrasive wear, adhesive, flaking, chipping at the cutting edge and coating delamination.

Research of Surface Finish during Titanium Alloy Turning

“…Error sources occurring in turning of titanium and its alloy can be divided into two classes: error sources depending on the load (cutting force, cutting heat causes part distortions, tool wear, insufficient static rigidity of the machining system) and error sources independent of the load, e.g. uneven allowances cause force fluctuation and form error and release stresses, inhomogeneity of the work piece material, and construction of the clamping device [12,13].…”