Papers by Author: Engel P. Pechkovsky

Abstract: Regularities, features and mechanisms of deformation and fracture processes of new ceramic materials – porous (=3-35 %) two-phase titanium nanolaminate-composites Ti3SiC2/TiC, Ti3AlC2/TiC, Ti4AlN3/TiN (content of TiC or TiN – 5-70 % vol.) at 20-1300 оС are established. Composites are made by reaction sintering. On increase in mechanical properties and resistance to deformation they settle down in the following sequence: Ti3AlC2/TiC–Ti4AlN3/TiN–Ti3SiC2/TiC. In porous nanolaminate-composites containing less than 20 % TiC the increase in porosity  results in decrease in high-temperature strength pl and increase of plasticity . Appreciable increase of strength of porous composites is marked at content TiC>25-30 % (vol.).

Abstract: The influence of passing from a microcrystalline to a nanocrystalline structure on the mechanical properties of chromium deposited by magnetron sputtering is studied. The possibility of additional strengthening nanomaterials due to enrichment of grain boundaries by “useful” additives elements is established. A wide spectrum of materials in different structural states was investigated by the method of micromechanical tests. The notions of the “theoretical” hardness (largest hardness for the material) and “limit tool” hardness, connected with tool limitations in indentation, are introduced.