Preparation of (Cr1-x, Mox)2(C, N) infinite solid solution powders

Abstract

(Cr1-x,Mox)2(C,N) (x = 0–1) infinite solid solution powders were successfully prepared through carbothermal reduction nitridation method, for the first time. The phase and morphology evolutions, with the various synthesis temperature, isothermal time and Mo content, were systematically discussed by using TG-DSC, XRD, SEM and chemical composition analysis. The results show that phase evolution follows the sequences of (Cr2O3, MoO3) → (Cr2O3, MoO2) → (Cr2O3, Mo2C) → (Cr2O3, Cr3C2, (Cr1-x,Mox)2(C,N)) → (Cr2O3, (Cr1-x,Mox)2(C,N)) → single-phase (Cr1-x,Mox)2(C,N). Properly elevating synthesis temperature and prolonging isothermal time benefit the reduction of oxygen and nitridation of (Cr1-x,Mox)2(C,N). The optimal preparation temperature and isothermal time should be 1200 °C and 1 h, respectively. Increasing Mo content enlarges the lattice parameters of (Cr1-x,Mox)2(C,N) by obeying the Vegard's law, meanwhile, refines the particles from ~5 μm (x = 0) to ~100 nm (x = 1).