Influence of nanosize particles and methods of mixing on mechanical abilities of SP-70 powder steel

Resumo

The influence of the mixing method and nature of the administered nanoparticles on the mechanical properties of powder steels is considered. The dependences of hardness and tensile strength under three-point bending on the concentration of nanosized additives and conditions of mixing and sintering were determined. The obtained experimental dependence showed that the maximum values of hardness and strength are achieved at a silicon nitride concentration of 0.1 wt % and under a two-stage mixing technology: mixing in an ultrasonic bath and subsequent mixing in a Turbula mixer for 30 min. It is shown also that, after mixing according to a two-stage scheme and mixing in a planetary centrifugal mill, the mechanical properties almost reached their maximum values already during sintering at the temperature of 1273 K for 120 min, and a further increase in time and temperature of exposure does not have a significant effect on their value.