Adiabatic shear banding and scaling laws in chip formation with application to cutting of Ti-6Al-4V
Alain Molinari (University of Lorraine), Henar Miguelez (), Xavier Soldani ()
Symposium in honor of Rod Clifton on the occasion of his 75th Birthday
Mon 10:45 - 12:15
Salomon 101
The phenomenon of adiabatic shear banding is analyzed theoretically in the context of metal cutting. The mechanisms of material weakening that are accounted for are: (i) thermal softening and (ii) material failure related to a critical value of the cumulated plastic strain. Orthogonal cutting is viewed as a unique configuration where adiabatic shear bands can be experimentally produced under well controlled loading conditions by individually tuning the cutting speed, the feed (uncut chip thickness) and the tool geometry. The role of cutting conditions on adiabatic shear banding and chip serration is investigated by combining finite element calculations and analytical modeling. This leads to the characterization and classification of different regimes of shear banding and the determination of scaling laws which involve dimensionless parameters representative of thermal and inertia effects. The analysis gives new insights into the physical aspects of plastic flow instability in chip formation. The originality with respect to classical works on adiabatic shear banding stems from the various facets of cutting conditions that influence shear banding and from the specific role exercised by convective flow on the evolution of shear bands.