圧縮ねじり加工における試料内せん断ひずみ分布に対する回転回数の影響

抄録

Compressive torsion processing (CTP) can cause huge shear strain in a cylindrical workpiece by simultaneous compressive and torsional loading without changing the cylindrical shape. In the present work, the distribution of shear strain in a specimen subjected to CTP was measured in a model experiment using two kinds of aluminum alloys, and the effect of the number of revolutions on the strain distribution was investigated. Internal shear strain of the worked specimen can be quantified by measuring the displacement of the interface between the two kinds of alloys in the cross section. The shear strain in the worked specimen has a gradient distribution not only in the radial direction owing to the geometric feature, but also in the axial direction because of the frictional constraint of the container. However, the measured shear strain was almost in agreement with value predicted by geometric calculation. The shear strain distributions were proportional to the radius and number of revolutions in the part of less than 15 mm in radius of a cylindrical specimen 41 mm in diameter and 10 mm in height.