An earlier study demonstrated the feasibility of effectively scaling the ECAP
process to include billets having diameters from 6 to 40mm [9] and in these experiments some tensile specimens, having gauge lengths of 5 mm, were cut from the 40mm billet with their gauge lengths oriented in two mutually orthogonal directions perpendicular to the pressing direction. Although the subsequent curves of stress versus strain were essentially identical for all of these tensile specimens and for other specimens cut parallel to the pressing direction, thereby
suggesting a reasonably homogeneous microstructure, the results are insufficient to provide detailed information on either the degree of homogeneity within the cross-sections or the changes in any inhomogeneities with increasing numbers of passes through the die. This information is necessary because the microstructure may change in the vicinity of the die walls if, for example, frictional effects become important.
An earlier study demonstrated the feasibility of effectively scaling the ECAPprocess to include billets having diameters from 6 to 40mm [9] and in these experiments some tensile specimens, having gauge lengths of 5 mm, were cut from the 40mm billet with their gauge lengths oriented in two mutually orthogonal directions perpendicular to the pressing direction. Although the subsequent curves of stress versus strain were essentially identical for all of these tensile specimens and for other specimens cut parallel to the pressing direction, therebysuggesting a reasonably homogeneous microstructure, the results are insufficient to provide detailed information on either the degree of homogeneity within the cross-sections or the changes in any inhomogeneities with increasing numbers of passes through the die. This information is necessary because the microstructure may change in the vicinity of the die walls if, for example, frictional effects become important.
การแปล กรุณารอสักครู่..
