LUKÁČ František

Spoluautoři VLČEK Marián, STULÍKOVÁ Ivana, SMOLA Bohumil, KUDRNOVÁ Hana, VLACH Martin, KEKULE Tomáš, SZAKÁCS Gábor, HORT Norbert, KAINER Karl Ulrich

Biodegradable alloys based on magnesium recently receive a lot of public attention due to requests for implants that do not need removing after healing process. Such implants improving quality of life of the individual highly demand proper mechanical properties, biocompatibility and optimal corrosion in bodily fluids. In this work we designed and investigated the properties of magnesium alloy containing rare earth metals, namely yttrium and neodymium, with an addition of silver showing the evidence of antibacterial effects and promising corrosion rate in a body [1]. The as-cast Mg-Y-Nd-Ag alloy (not exceeding 6 wt. % of solutes) exhibits hard regions of eutectics containing Y, Nd and Ag. The eutectic regions continuously dissolve at 500 °C with increasing time while new particles develop in form of discs embedded in the magnesium matrix parallel to each other within a grain. During this process, an overall microhardness decreases to its minimum value. However, after homogenization annealing at 525 °C neither eutectic regions nor disc-shape particles were revealed in scanning electron microscope even though the microstructure development during the prolonged annealing at 525 °C leads to superior microhardness value. Structure and microhardness values are compared to other investigated Mg-Y-Nd-based alloys (e.g. [2,3]). Microhardness measurements, electrical resistivity measurements at low temperature, scanning electron microscopy and in-situ synchrotron diffraction methods were used in this work. References [1] TIE, D., FEYERABEND, F., MÜLLER, W.D., SCHADE, R., LIEFEITH, K., KAINER, K.U., WILLUMEIT, R. Antibacterial biodegradable Mg-Ag alloys. European Cells and Materials 25, 2013, s. 284-298. [2] VLACH, M., SMOLA, B., CÍSAŘOVÁ, H., STULÍKOVÁ, I. Precipitation Processes in Mg-Y-Nd Alloys. Defect and Diffusion Forum, Volumes 334-335, 2013, s.155-160. [3] TOLNAI, D., MENDIS, C.L., STARK, A., SZAKÁCS, G., WIESE, B., KAINER, K.U., HORT, N. In situ synchrotron diffraction of the solidification of Mg4Y3Nd. Materials Letters, Volumes 102-103, 2013, s. 62-64