Precision turning analysis of Ti-6Al-4V skin produced by selective laser melting using a design of experiment approach

Additive manufacturing (AM) processes are particularly interesting to reduce the weight of a part by associate lattice structures to thin skin. To ensure a finished product with the dimensional and structural requirements of an industrial part, a post-machining is necessary. The proposed work studied the surface integrity after the dry precision turning of a thin wall of Ti-6Al-4V part produced by sintering laser melting (SLM), using uncoated carbide tool with various cutting angles and tool nose radius. A design of experimental approach (DOE) is used. Different techniques are combined to characterize cutting performance and surface integrity including cutting forces, residual stresses, micro-hardness, and SEM microscopy. Observation reveals that the finish-cutting of near net shape part obtain by SLM induces a minimal effect on surface integrity. Even the dry condition, the low thermal conduction of titanium alloys and the 1 mm skin thickness obtained after cutting operation, damages on surface and subsurface are negligible (< 1 μm).