The effect of TaC on grains and packets coarsening in the reduced activation ferritic/martensitic(RAFM)steels was investigated.It was found that the combined effect of the austenitizing temperature and heating rate resulted in the heterogeneous austenite grain growth.When the austenitizing temperature was raised above 1423 K,the TaC particles disappeared,and the homogenous grains abruptly increased.The thermodynamic model for dissolution of TaC particles during austenitizing was applied to interpret the results.
Electronic and magnetic properties of CeN are investigated using first-principles calculations based on density functional theory(DFT) with the LDA + U method.Our results show that CeN is a half-metal.The majority-spin electron band structure has metallic intersections,whereas the minority-spin electron band structure has a semiconducting gap straddling the Fermi level.A small indirect energy gap occurs between X and W.The calculated magnetic moment is 0.99 μB per unit cell.
The structural,elastic,electronic,and thermodynamic properties of Zr x Nb1-x C alloys are investigated using the first principles method based on the density functional theory.The results show that the structural properties of Zr x Nb1-x C alloys vary continuously with the increase of Zr composition.The alloy possesses both the highest shear modulus(215 GPa)and a higher bulk modulus(294 GPa),with a Zr composition of 0.21.Meanwhile,the Zr0.21Nb0.79C alloy shows metallic conductivity based on the analysis of the density of states.In addition,the thermodynamic stability of the designed alloys is estimated using the calculated enthalpy of mixing.
