Using severe plastic deformation to prepare of ultra fine-grained materials by ECAP method

• Autorzy: Rusz S. , Malanik K.
• Języki publikacji: EN

Abstrakty

EN

Purpose: The purpose of the paper is to design a tool and propose a procedure for verification of development of structure at equal channel angular pressing. The goal is to obtain after extrusion the semi-products of AlCuMg alloys a fine-grain structure which one hand increases strength properties and plasticity, and on the other hand is possible to use it at selected cases for subsequent deformations under conditions of "super-plastic state". Design/methodology/approach: The experiments were aimed the verification of functionality of the proposed equipment, determination of deformation resistance, deformability and change of structure at extrusion of the alloy AlCu4Mg2. Deformation forces were measured at extrusion. The average grain size in cross direction was determined by quantitative metallographic methods. TEM analysis of the structure of AlCu4Mg2 were also made. Findings: The structural analysis of AlCu4Mg2 alloy made by TEM has demonstrated a perfect suitability of the ECAP die design. The process results in a very fine grain structure (100-200 nm) throughout the sample overall volume, at which the starting average grain size was 150 µm. Practical implications: Aluminium alloys of super fine granularity structure are basic intermediate products realised by ECAP technologies. The state of super fine granularity facilitates forming of material in the so-called 'superplastic state'. The achievement of the desired structure depends primarily on the tool geometry, number of passages through the die, magnitude and speed of deformation, process temperature, and lubrication mode. Originality/value: It has been demonstrated that the extrusion technology is suitable for attaining of grain nano-structure in the material investigated in order to determine the number of extrusion cycles needed and the appropriate canal angle with corresponding internal and external bend radii. The obtained results make for success of further investigative efforts in the area.

Słowa kluczowe

EN

severe plastic deformation; die geometry; microstructures analyse; ECAP technology

PL

intensywne odkształcenia plastyczne; analiza mikrostruktury; technologia ECAP

• Wydawca: International OCSCO World Press
• Czasopismo: Archives of Materials Science and Engineering
• Rocznik: 2007
• Tom: Vol. 28, nr 11
• Strony: 683--686
• Opis fizyczny: Bibliogr. 15 poz., il., wykr.

Twórcy

autor

Rusz S.

autor

Malanik K.

• Faculty of Mechanical Engineering, VSB-Technical university of Ostrava, 17 listopadu 15, 708 33 Ostrava-Poruba, Czech Republic,

Bibliografia

• [1] Y. Iwahashi, J. Wang, Z. Horita, M. Nemoto, T. Langdon, Principle of equal-channel angular pressing for the processing of ultra-fine grained materials, Scripta Materialia 35 (1996) 143-146.
• [2] R. Z. Valiev, Some new trends in SPD Processing for fabrication of bulk nanostructured materials, Proceedings of the 3rd International Conference on Nanomaterials by severe plastic deformation, Fukuoka, Japan, 2005, 3-10.
• [3] V. M. Segal, Materials processing by simple shear, Materials Science and Engineering A197 (1995)157-164.
• [4] X. Cheng, M. Furukawa, Z. Horita, T. G. Langdon, Developing a model for grain refinement in Equal-Channel angular Pressing, Proceedings of the 3rd International Conference on Nanomaterials by severe plastic deformation, Fukuoka, Japan, 2005, 19-24.
• [5] H. C. Shin, T. K. Ha, Y. W. Chang, Kinetics of deformation induced martensitic transformation in a 304 stainless steel Scripta Materialia 45 (2001) 823-829.
• [6] Z. Horita, M. Furukawa, M. Nemoto, T. G. Langdon, Development of fine grained structures using severe plastic deformation, Materials Science and Technology 3 (2002) 1239-1245.
• [7] T. Hebesberger, A. Vohauer, R. Wadsak, H. P. Stúwe, R. Pippan, Production, structure and properties of nanocrystalline materials, BHM 147 (2002) 358-363.
• [8] L. I. Saiyi, I. J. Beyerlein, C. T. Necker, D. J. Alexander, Heterogeneity of deformation texture in equal channel angular extrusion of copper, Acta Materialia 52 1459-1475.
• [9] X. Cheng, T. G. Langdon, Influence of a round Conner die on flow homogeneity in ECA pressing, Scripta Materialia 48 (2002) 1-4.
• [10] M. Gutkin, I. A. Ovidko, C. S. Pande, Theoretical models of plastic deformation processes in nanocrystalline materials, Reviews on Advanced Materials Science 2 (2001) 80-102.
• [11] L. A. Dobrzański, R. Maniara, J. H. Sokolowski, The effect of cast Al-Si-Cu alloy solidification rate on alloy thermal characteristics, Journal of Achievements in Materials and Manufacturing Engineering 17 (2006) 217-220.
• [12] L. A. Dobrzański, W. Borek, R. Maniara, Influence of the crystallization condition on Al-Si-Cu casting alloys structure, Journal of Achievements in Materials and Manufacturing Engineering 18 (2006) 211-214.
• [13] I. J. Beyerlein, R. A. Lebensohn, C. N. Tome, Ultrafine Grained Materials II, TMS, Seattle, 2002.
• [14] M. Furukawa, Z. Horita, H. G. Langdon, Factors influencing the shearing patterns in equal-channel angular pressing, Materials Science and Engneering A332 (2002) 97-109.
• [15] J. H. Lee, I. H. Son, Y. T. Im, Finite element investigation of equal channel angular extrusion process, Materials Transactions, The Japan Institute of Metals 45 (2004) 2165-2171.