温度和气氛对锰稳定氧化锆立方相稳定性的影响

Effect of Temperature and Atmosphere on Stabilities of Cubic Mn-Stabilized Zirconia

研究了采用传统的固相反应法制备具有单一立方相结构的锰稳定氧化锆陶瓷,并对影响锰稳定立方氧化锆稳定性的温度和气氛进行了分析.结果表明:当锰的掺杂量(原子分数)为20%时,氧化锆为单一立方相结构.对于具有立方相结构的氧化锆固溶体的相稳定研究发现,在1 000℃以上的高氧分压条件下,立方相易发生向单斜相相变;在1 000℃低氧分压的条件下,立方相结构相对稳定;在温度低于800℃条件下,无论氧分压的高低,立方相均能稳定存在,只是在高分压氧下伴随立方相晶格常数的减小及Mn元素价态的变化.

The stability of cubic Mn-stabilized zirconia prepared by traditional solid-state reaction was investigated at different annealing temperatures and atmospheres, lhe results showed that when the concentration of Mn element is 20at. %, the zirconia is a cubic structure. For the single phase Mn-stabilized zirconia, the cubic phase is unstable and changes into a monoclinic structure at high oxygen partial pressure at the temperature higher than 1 000 ℃, but relative stable at the lower partial pressure. When annealed at the temperature lower than 800 ℃, the cubic structure does not change, and it is not affected by the partial pressure. The differences are that when the cubic samples annealed at 800 ℃ for longer time in O2, the lattice parameters of cubic zirconia become smaller and the valence state of Mn changes into higher valence.