The performance of PCD tools in high-speed milling of Ti6Al4V

Abstract

Tool performance of conventional tools is poor and a major constraint when used in milling titanium alloys at elevated cutting speeds. At these high cutting speeds, the chemical and mechanical properties of Ti6Al4V cause complex wear mechanisms. In this paper, a fine-grain polycrystalline diamond (PCD) end mill tool was tested, and its wear behavior was studied. The performance of the PCD tool has been investigated in terms of tool life, cutting forces, and surface roughness. The PCD tool yielded longer tool life than a coated carbide tool at cutting speeds above 100 m/min. A slower wear progression was found with an increase in cutting speeds, whereas the norm is an exponential increase in tool wear at elevated speeds. Observations based on scanning electron microscope (SEM) and energy dispersive spectroscopy (EDAX) analysis suggest that adhesion of the workpiece is the wear main type, after which degradation of the tools accelerates probable due to the combined effect of high temperature degradation coupled with abrasion.

OVERVIEW OF WORK PIECE TEMPERATURE MEASUREMENT TECHNIQUES FOR MACHINING OF Ti6Al4V#

“…Ti6Al4V combines an exceptionally low thermal conductivity, high chemical reactivity at the temperatures encountered in contemporary high productivity machining, and a low modulus of elasticity [1]. So the cutting speeds (v c ) are limited to relatively low values [2]. When Ti6Al4V is milled, high temperatures at the cutting tool/work piece interface and prominent friction phenomena are encountered.…”

“…Ultimately it presents a very real risk factor in aerospace manufacture [4]. In civil aviation, scheduled inspections to detect early fatigue crack are extensive.…”

Finite element analysis and modeling of temperature distribution in turning of titanium alloys

“…This may be due to the formation of the serrated chip and vibration (chattering). The cutting force and temperature from turning of titanium workpiece with PCD tool are validated with the research findings of Oosthuizen et al [22] and Pan [23] respectively. From the validation test, the cutting force and temperature show the maximum variation of 22.34% and 34.86% respectively.…”

Tool wear behaviour and workpiece surface integrity when turning Ti–6Al–2Sn–4Zr–6Mo with polycrystalline diamond tooling

“…Recent publications when milling titanium with PCD tooling have also shown favourable results at higher speeds than used for WC. When cutting Ti-6Al-4V, Oosthuizen et al [15] reported on tool life/wear when operating at 100-300 m/min, with slower wear progression and reduced cutting force occurring at 200 m/min. Similarly, Li et al [16] identified 250 m/min cutting speed as providing the lowest flank wear in face milling tests operating at up to 1000 m/min with a feed and axial depth of cut of 0.05 mm/tooth and 0.5 mm respectively.…”