Microstructural and mechanical characteristics of AlSiMnFe alloy processed by equal channel angular pressing

In the present research, equal channel angular pressing (ECAP) was conducted. The defectness degree of the alloy for one pass and maximum strain was determined. Ultra fine grained AlSiMnFe alloy was produced by refining grained annealed bulk by multi-pass ECAP at room temperature. The results reveal two regimes: from 1 to 2 passes the microstructure evolves to a equiaxed of ultrafine grains and from 2 to 4 passes there is no strict change in the average grain size

The effect of cross rolling on the microstructure of ferrous and non-ferrous metals and alloys

The cross rolling is the one of most perspective method of refinement microstructure metals by severe plastic deformation method. This method gives ability to get the long length billets. However, deformation and trajectories of the metal is very heterogeneous across the section of the rolled piece. This paper presents the finite element method (FEM) simulation of hot cross rolling and experimental study of the effect of the cross rolling on a different threeroll mills on the microstructure of ordinary structural alloy steel, stainless steel and technical copper in different zones of the bar. Analysis showed significant structure refinement in all cases. The best result was achieved on the stainless steel, and shown the formation of equal-axis ultra-fine-grain structure on the bar periphery

Study of deformation behavior, structure and mechanical properties of the AlSiMnFe alloy during ECAP-PBP

The presented article deals with the effects of equal channel angular pressing (ECAP) with a newly adjusted die geometry on the microstructure and mechanical properties of the Al–Si–Mn–Fe alloy. This alloy was subjected to two modes of heat treatment followed by the ECAP process, which led to partial back pressure (ECAP-PBP). Ultra-fine grained (UFG) structure formed through ECAP-PBP process has been studied by methods of optical as well as electron microscopy. The obtained results indicate that quenched alloys, in comparison to slowly cooled alloys, do not contain large brittle particles which subsequently initiate a premature creation of cracks. It was shown that the mechanical properties of these alloys after such processing depend first and foremost on the selected type of heat treatment and on the number of performed passes. The maximum of ultimate tensile strength (417 MPa) was obtained for quenched alloy after 3 passes. On the other hand, maximum ductility was found in slowly cooled alloy after second pass. Further passes reduced strength due to the brittle behavior of excluded particles. One of the partial findings is that there is only a small dependency of the resulting size of grains on previously applied thermal processing. The minimum grain sizes were obtained after 3 passages, where their size ranged between 0.4 and 0.8 μm. The application of quick cooling after heat processing due to the occurrence of finer precipitates in the matrix seems to produce better results.Web of Science4421721

EXPERIMENTAL STUDY ON POWER PARAMETERS OF “ROLLING - ECA-PRESSING” COMBINED PROCESS

Introduction.  Power  parameters  of  the  “rolling  −  equalchannel angular pressing” (ECA) combined process are studied. The work objective is to determine forces of rolling and pressing in the deformation by the combined method.Materials and Methods. The die strength calculation and the experiment on deformation of AISI 6063 aluminum samples were carried out. During the experiment, the force values were recorded using a strain-gauge station.Research Results. The strength analysis results show that this die design is suitable for creating an experimental stand of the “rolling − ECA-pressing” combined process, since the calculated  safety  margin  is  sufficient  to  implement  the  pressing under extreme conditions. The rolling forces at all stages of the  deformation  exceed  the  corresponding  pressing  forces, which is a necessary condition for the combined process. Discussion and Conclusions. The obtained results can be used in the design of experimental stands that implement the investigated combined  process. Herewith, the given  strain-gauge method for studying strength characteristics is suitable for the case of calibrated rolls

The effect of cross rolling on the microstructure of ferrous and non-ferrous metals and alloys

The cross rolling is the one of most perspective method of refinement microstructure metals by severe plastic deformation method. This method gives ability to get the long length billets. However, deformation and trajectories of the metal is very heterogeneous across the section of the rolled piece. This paper presents the finite element method (FEM) simulation of hot cross rolling and experimental study of the effect of the cross rolling on a different threeroll mills on the microstructure of ordinary structural alloy steel, stainless steel and technical copper in different zones of the bar. Analysis showed significant structure refinement in all cases. The best result was achieved on the stainless steel, and shown the formation of equal-axis ultra-fine-grain structure on the bar periphery