Kinetics of the changes in the mechanical properties of the samples from the Cu-0.5Cr copper alloy and Grade 4 Ti during alternating bending
Abstrakt
In this work, we study the features of the deformation processing by alternating free bending of axisymmetrical billets aimed at increasing the mechanical properties of long-length metallic billets without changing their cross-section. As the materials for the study, we selected a chromium bronze for electrical engineering applications and commercially pure (CP) titanium.
Using mathematical modeling in the DEFORM-3D software package, we studied the stress-strain state of the samples of the investigated materials during multi-cycle alternating bending. It is established that an increase in the number of processing cycles provides a more symmetrical distribution of accumulated strain in the billet section.
By means of a physical experiment we investigated the character of strengthening and found some regularities during the processing by alternating bending. It is shown that an increase in the number of processing cycles provides a gradient and more symmetrical microhardness distribution in the billet section, which correlates with the data for the strain state, obtained by computer simulation.
The strengthening intensity of the Cu alloy is twice as high as that of CP Ti, the other conditions being the same. For instance, in the Cu-0.5Cr copper alloy billets the peripheral layers experience a more intensive strengthening, and already after a single processing cycle their hardness is almost 1.5 times higher than that in the central region, and after 8 processing cycles, irrespective of the processing route, microhardness is on average 1.8 times higher than that in the initial state.
Processing routes. and. produce a more symmetrical microhardness distribution field in the billet section. The most efficient, in terms of strengthening, bending routes are determined.
For the investigated alloys the most efficient route is route. which ensures a higher level of strengthening of both billets on the whole and their peripheral regions.