The experimental research and the numerical modeling of the fracture phenomena in micro scale

• Autorzy: Milenin A. , Byrska D. , Grydin O. , Shaper M.

Warianty tytułu

PL

Badania eksperymentalne i numeryczne modelowanie zjawiska pekania w skali mikro

• Języki publikacji: EN

Abstrakty

EN

Magnesium alloys with increased bio-compatibility are applied in medicine for the sake of high compatibility and solubility in human body. Production of surgical threads to integration of tissue can be example of the application of these types of alloys. The MgCa0.8 magnesium alloy has a low plasticity at cold deformation, therefore, the drawing process of thin wire is difficult. Prediction of wire fracture in a drawing process of MgCa0.8 alloy is very important from theoretical and practical point of view. The macro scale fracture models are not capable to predict the important phenomena, such as cracking in grains boundaries, moment of initiation of micro-cracks, stress relaxation in grain after micro-cracking etc. Present work is dedicated to the development of a numerical model of MgCa0.8 fracture phenomena prediction in micro scale. The first part of the work is focused on experimental studies: tensile tests, which are data source for the flow stress model of MgCa0.8 alloy and metallographic analysis of material for micro scale fracture model. To understand fracture mechanism, physical modeling in 10000 N tensile/compression stage for a SEM for MgCa0.8 magnesium alloy was performed. This analysis shows that the material is cracking at the grain boundaries. Experiments in the chamber of SEM allows understanding of the fracture mechanism in special magnesium alloy MgCa0.8 and determining the empiric coefficients of fracture model in micro scale. The limit of deformation before initiations of micro-cracks was obtained. The second part of the work is focused on the development of the micro scale numerical model of fracture. The boundary element method is proposed for micro scale model. The mathematical model of fracture is developed for the two dimensional domain. The elastic-plastic theory of plasticity is used.

Słowa kluczowe

EN

magnesium alloys; MgCa0.8; drawing process; facture model; boundary element method

• Wydawca: Wydawnictwa AGH
• Czasopismo: Computer Methods in Materials Science
• Rocznik: 2010
• Tom: Vol. 10, No. 2
• Strony: 61--68
• Opis fizyczny: Bibliogr. 12 poz., rys.

Twórcy

autor

Milenin A.

autor

Byrska D.

autor

Grydin O.

autor

Shaper M.

• Faculty of Metal Engineering and Industrial Computer Science, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow, Poland,

Bibliografia

• Bach, Fr.-W., Hassel, T., Golovko, A.N., 2005, The Influece of the Chemical Composition and Extrution Parameters on the Mechanical Properties of Thin-Walled Tubes Made of Magnesium-Calcium Alloys, Suczasni problemy metalurgii, Naukovi visti, 8, Systemni technologii, 379-384.
• Bach, Fr.-W., Milenin, A., Kucharski, R., Borman, D., Kustra, P., 2007, Modelowanie za pomocą MES procesu ciągnienia drutów ze stopu magnezu wykorzystywanych w chirurgii, Hutnik, 1-2, 8-11.
• Crouch, S. L., Starfield, A. M., 1983, Boundary element methods in solid mechanics, GEORGE ALLEN & UNWIN, London, Boston, Sydney
• Diard, O., Leclerca, S., Rousselier, G., Cailletaud, G, 2002, Distribution of normal stress at grain boundaries in multicrystals: application to an intergranular damage modeling, Computational Materials Science, 18, 73-84.
• Haferkamp, H., Kaese, V., Niemeyer, M., Phillip, K., Phan-Tan, T., Heublein, B., Rohde R., 2001, Exploration of Magnesium Alloys as New Material for Implantation, Mat-wiss. u. Werkstofftech, 32: Wiley-VCH Verlag GmbH, Weinheim, 116-120.
• Kustra, P., Milenin, A., Schaper, M., Grydin, O., 2009, Multiscale modeling and interpretation of tensile test of magnesium alloy in microchamber for the SEM, Computer Methods in Materials Science, 9, 2, 207-214.
• Milenin, A., Kustra, P., 2008, The multiscale FEM simulation of wire fracture phenomena during drawing of Mg alloy, Steel Research International, 79, 717-722.
• Milenin, A., Byrska, D., Kustra, P., Heidenblut, T., Gridin, O., Schaper, M., 2010, A model of ductility phenomena of MgCa0.8 alloy in cold forming process, Rudy i Metale Nieżelazne, 4.
• Milenin A., 1997, Comparative analysis of boundary and finite element method possibilities in simulation of metal working processes, Russian metallurgy. Metally, 2, 64-71.
• Milenin, A., 1995, A plastic-deformation simulation of two-phase materials by the boundary-elements method, Metallofizika I Novejshie Tekhnologii, 17, 12, 46-52.
• Thomann, M., Krause, Ch., Bormann, D., N. von der Hoh, Windhagen, H., Meyer-Lindenberg A., 2009, Comparison of the resorbable magnesium alloys LAE442 and MgCa0.8 concerning their mechanical properties, their progress of degradation and the bone-implant-contact after 12 months implantation duration in a rabbit model, Mat.-wiss. u. Werkstofftech, AO, 1-2.
• Yoshida, K., 2004, Cold drawing of magnesium alloy wire and fabrication of microscrews, Steel Grips, 2, 199-202.