No abstract

No abstract

No abstract

No abstract

The effect of addition of submicrometer-sized B 4 C (5,10 and 15 wt%) on microstructure, phase composition, hardness, fracture toughness, scratch resistance, wear resistance, and thermal behavior of hot-pressed ZrB 2 -B 4 C composites is reported. ZrB 2 -B 4 C (10 wt%) composite has V H1 of 20.81 GPa and fracture toughness of 3.93 at 1 kgf, scratch resistance coefficient of 0.40, wear resistance coefficient of 0.01, and ware rate of 0.49 9 10 À3 mm 3 /Nm at 10N. Crack deflection by homogeneously dispersed submicrometer-sized B 4 C in ZrB 2 matrix can improve the mechanical and tribological properties. Thermal conductivity of ZrB 2 -B 4 C composites varied from 70.13 to 45.30 W/m K between 100°C and 1000°C which is encouraging for making ultra-high temperature ceramics (UHTC) component.

No abstract

No abstract

Excited states of 127Xe were populated in the 122Sn(9Be, 4nγ) fusion-evaporation reaction at a beam energy of 48 MeV. A sequence of ΔI = 2 γ-transitions has been observed above the Iπ = 19/2+ state at 2307 keV. Spin and parity of the states belonging to this band have been assigned firmly. The dynamic moment of inertia of this band is found to be low and almost constant as a function of angular momentum. Observed experimental features along with the results of theoretical semiclassical model calculation suggest an antimagnetic rotational character for this band.