Page 34 - machining_titanium_05_2019

MILLING TITANIUM

Fig. 15 MULTI-MASTER face milling head MM FM

In this case starting feed per tooth fz can be found with the use of equation (7a):
fz=fzo×Kf×1/sinχ ×Ks (7a)
Here: fzo – basic feed per tooth (Table 20),
Kf – tooth-strength factor (Table 17)
χ – cutting edge (entering) angle.

Example

A producer of titanium components needs to machine a plane surface of a large-size part, which is
made from Ti-6Al-4V. 200 mm dia. milling cutter SOF45 8/16-D200-14-60R carrying inserts
ONHU 050500-PL IC830 is intended for applying in finish milling the surface. The depth of cut and the
width of cut are 1.5 mm and 160 mm correspondingly. Which cutting speed and feed should be set?

Cutting edge angle χ=45°, ae/d=0.8, the type of machining is considered as light (Table 6),
and operational stability is assumed as sufficient.

For carbide grade IC830 Vo=55 m/min or 180 sfm (Table 7), Km=1 (Table 9),Ke≈0.92 (Table10), Ks=1.
Hence, from equation (1) Vc=55×1×0.92×1=50.6 (mm/min) ≈51 m/min (167 sfm).
n=1000×51/π/200=81 (rpm).

Table 18 gives fzo=0.125 mm/tooth (.0049 ipt), 1/sin45°=1.4 (Table 19); and using equation (7)
fz=0.125×1.4×1=0.175 (mm/tooth) (.0069 ipt).
Vf=0.175×14×81=198 (mm/min) (7.82 ipm).

Table 20 Basic Feed per Tooth fzo and Chip Thickness Data for
Face Milling by Solid Carbide and MULTI-MASTER Tools
Fzo, hm and hmax for carbide grade
Main grades
IC900 IC300
Parameters IC908 IC308
hm 0.049 (.0019) 0.052 (.002)
hmax 0.057 (.0022) 0.06 (.0024)
fzo 0.057 (.0022) 0.06 (.0024)
* The table values are given in metric units with their US customary equivalents
in italic brackets: fz in mm/tooth (ipt), hm and hmax in mm (in)

32 ISCAR