抄録
Microcutting mechanism of amorphous metals is elucidated by means of in-situ SEM observation of chip formation process. Orthogonal microcutting tests are conducted on rapidly quenched Fe-base amorphous alloys, using diamond tools with selected rake angles. The depth of cut is employed in the range of 0.5 to 15 μm. The amorphous metals produce so-called card model type chip exhibiting lamellar slip structure, which has been formed due to periodical occurrence of homogeneous plastic deformation in the primary deformation zone and following catastrophic shear along the localized band. The lamellar slip spacing is found to be proportional to the depth of cut. The size effect on the specific cutting force is not obvious. It is also found that the shear stress along the shear zone is almost independent of the depth of cut, the normal stress, the shear strain and the strain rate. These characteristic features being different from conventional crystalline metals are discussed in terms of inherent deformation properties to the amorphous metals.
