Device “DRECE - Dual Rolls Equal Channel Extrusion” is used for production of metallic materials with very fine grain size (UFG). During the actual forming process the principle of severe plastic deformation is used. Metallic strip with dimensions 57×2×1000 mm is inserted into the device. During the forming process the main cylinder in synergy with the pressure roller extrude the material through the forming tool without any change of cross section of the strip. In this way a significant refinement of grain is achieved by severe plastic deformation. This method is used for various types of metallic materials, non-ferrous metals and their alloys. The DRECE device is also being verified from the viewpoint of achievement of a UFG structure in a blank of circular cross-section (wire) with diameter of ϕ 8 mm × 1000 mm.
S. Rusz, A. Kłyszewski, M. Salajka, O. Hilser, L. Cizek and M. Klos
S. Rusz, L. Cizek, M. Salajka, S. Tylsar, J. Kedron, V. Michenka, T. Donic, E. Hadasik and M. Klos
One of the ways to the more effective use of metallic materials is their processing by forming. At present in this the area the use of the process of severe plastic deformation (SPD process), leading to a refinement of the structure (materials with UFG structure) and thus to achievement of higher level of their utility value, is expanding. AlMn1Cu alloy is commercially produced aluminum alloy by the company Al Invest Bridlicna (the cast strip with a mild reduction by rolling up to 10% to the thickness of 10 and 15 mm, which has its uses especially in engineering. AZ31 alloy is commercially produced aluminum alloy after casting and extrusion at 400°C on final rod with 20 mm diameter. For experimental purposes from the belts of alloys the test samples of the underlying dimensions of 10x10 mm length 40 mm (geometry with channel deflection 20°) and 15x15 mm length 60 mm (geometry with helix matrix) in the direction of rolling were made. All three instruments are made of high tool steel - HOTVAR. For compare the influence of geometry ECAP tool on structure refining was used AlMn1Cu and AZ31 alloys were used three specially made tools ECAP, differing mainly in the construction design.
L. Cizek, S. Rusz, O. Hilser, R. Śliwa, D. Kuc, T. Tański and M. Tkocz
A growing interest in wrought magnesium alloys has been noticed recently, mainly due to development of various SPD (severe plastic deformation) methods that enable significant refinement of the microstructure and – as a result – improvement of various functional properties of products. However, forming as-cast magnesium alloys with the increased aluminum content at room temperature is almost impossible. Therefore, application of heat treatment before forming or forming at elevated temperature is recommended for these alloys. The paper presents the influence of selected heat treatment conditions on the microstructure and the mechanical properties of the as-cast AZ91 alloy. Deformation behaviour of the as-cast AZ61 alloy at elevated temperatures was analysed as well. The microstructure analysis was performed by means of both light microscopy and SEM. The latter one was used also for fracture analysis. Moreover, the effect of chemical composition modification by lithium addition on the microstructure of the AZ31-based alloy is presented. The test results can be helpful in preparation of the magnesium-aluminum alloys for further processing by means of SPD methods.