Workpiece surface integrity when slot milling γ-TiAl intermetallic alloy

Slot milling is presented as a potential manufacturing route for aerospace component feature production when machining γ-TiAl intermetallic alloy Ti–45Al–2Mn–2Nb + 0.8 vol.% TiB2XD using 2 mm diameter AlTiN coated WC ball nose end milling cutters. When operating with flood cutting fluid at v = 88 m/min, f = 0.05 mm/tooth, d = 0.2 mm, maximum flank wear was ∼65 μm after 25 min. SEM micrographs of slot surfaces show re-deposited/adhered and smeared workpiece material to a length of ∼50 μm. Brittle fracture of the slot edges was restricted to <10 μm with sporadic top burr formation observed up to ∼20 μm. Cross sectional micrographs of the slot sidewalls showed bending of the lamellae limited to within 5 μm.