The important role played by machining processes in the aircraft industry becomes clear when considering the staggering extent of machining involved in the production of aircraft parts. The load-bearing structures of aircraft wings, for instance, are milled from solid stock - a substantial amount of metal is removed in such processes. Aluminium is, essentially, an easily machined material but, being relatively soft and highly ductile, tends to smear when machined. Cold hardening leads to the formation of built-up cutting edges. The resulting change in the cutting edge geometry strictly limits the number of components that can be made with the required quality.
Mecachrome of France was one of the companies to demonstrate that this quantity can be increased by a factor of three by the use of a BALINIT® coating. The extended service life of the tool not only saves tooling costs but also increases productivity significantly through shortened setting up times.
Milling an aluminium alloy
Workpiece material: Aluminium alloy AISI 7175 (AlZnMgCu1.5)
Tool: Carbide inserted milling cutter Diam. 40 mm
Lubrication:
uncoated: wet
coated: dry
Cutting parameter:
vc = 628 m/min
vf = 1,000 mm/min
ap = 37.0 mm
ae = 15.0 mm
Source:
Mecachrome, France
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