Abstract The effect of shearing speed on the quality of shape and edge-face of the sheared-off products is studied. The tested material is a commercially pure aluminum. The maximum shearing speed is 10 m/s. It is evidenced that the shape quality of the sheared-off parts is better when a smaller clearance and a higher rate of shearing are applied. A thin ring of almost complete rectangular cross-section, i.e. 1.5 mm in width and 10 mm in height, whose edge-face is glossy, is successfully produced by the high-rate shearing process using a constraint tool set at the outer periphery of the sheet blank. It is demonstrated clearly by the pictures of microstructure that the material flow is concentrated within a very narrow band, showing even a recrystallized structure. A theoretical analysis proves that the band is the so-called adiabatic shear band (ASB), and that even melting of material takes place within it. In the shearing process, first an ASB evolves, followed by melting in the early stage of shearing. The major stroke of the punch is occupied by an easy simple shearing in a melted state.
[1]
Y. Bai,et al.
Width of adiabatic shear bands
,
1985
.
[2]
M. Gotoh.
Improvements of J2-deformation theory and their applications to FEM analyses of large elastic− plastic deformation
,
1990
.
[3]
Yi-long Bai.
Thermo-plastic instability in simple shear
,
1982
.
[4]
A. Molinari,et al.
Analytical Characterization of Shear Localization in Thermoviscoplastic Materials
,
1987
.
[5]
Viggo Tvergaard,et al.
Flow Localization in the Plane Strain Tensile Test
,
1981
.
[6]
J. Duffy,et al.
An experimental study of the formation process of adiabatic shear bands in a structural steel
,
1988
.
[7]
Alain Molinari,et al.
Instability and localization of plastic flow in shear at high strain rates
,
1987
.
[8]
J. Duffy,et al.
Measurement of the temperature profile during shear band formation in steels deforming at high strain rates
,
1987
.