Discontinuities of Plastic Deformation in Metallic Glasses with Different Glass Forming Ability

AbstractThe metallic ribbons Fe40Ni40B20, Cu47Ti35Zr11Ni6Si1 and Zr65Cu17.5Ni10Al7.5 with different microhardness and glass forming ability were studied at different loading rates from 0.05 to 100 mN/s. We describe in details the differences in elemental discontinuities on the loading curves for the studied alloys. It was found that the discontinuities began at a certain local deformation independently on the macroscopic mechanical properties of a ribbon. More developed discontinuities at higher deformations are created for the materials with lower microhardness and so lower strength

Utilization of poplar wood sawdust for heavy metals removal from model solutions

Some kinds of natural organic materials have a potential for removal of heavy metal ions from wastewater. It is well known that cellulosic waste materials or by-products can be used as cheap adsorbents in chemical treatment process. In this paper, poplar wood sawdust were used for removal of Cu(II), Zn(II) and Fe(II) ions from model solutions with using the static and dynamic adsorption experiments. Infrared spectrometry of poplar wood sawdust confirmed the presence of the functional groups which correspond with hemicelluloses, cellulose and lignin. At static adsorption was achieved approximately of 80 % efficiency for all treated model solutions. Similar efficiency of the adsorption processes was reached after 5 min at dynamic condition. The highest efficiency of Cu(II) removal (98 %) was observed after 30 min of dynamic adsorption. Changes of pH values confirmed a mechanism of ion exchange on the beginning of the adsorption process

Nanoindentation in Metallic Glasses with Different Plasticity

Nanoindentation and thermomechanical experiments on three types of metallic glasses with different glass forming ability were carried out. The nanoindentation behaviour at room temperature was associated with the creep at elevated temperatures. Different discontinuity populations and their shape observed on the nanoindentation loading curves were compared with morphology of plastic deformed indent regions. The influence of the differences in thermal stability of studied alloys on the nanoindentation in these alloys were studied as well

Nanoindentation Study of the Influence of the Loading Rate on the Deformation of Metallic Glasses

Nanoindentation experiments at the loading rates from 0.05 to 100 mN.s-1 on the amorphous FeNiB alloy were executed. We found that the serrations in the load-displacement (P-h) curve are more pronounced at lower loading rates and gradually disappear upon increasing loading rate. We have estimated the contribution of the inhomogeneous plastic deformation from pop-in events on the P-h curves. The pop-in population was compared with the morphology of indents