稀土对电沉积镍基复合镀层高温抗氧化性的影响

Effects of Rare Earth on Anti-Oxidized Behaviour of Electrodeposited Ni Matrix Gomposite Coatings at High Temperature

研究了稀土加入三种电沉积镍基复合镀层Ni—B_4C、Ni—TiC、Ni—ZrO_2前后,在850℃时的氧化行为。通过金相观察、ESCA(光电子能谱)分析及X射线衍射等方法研究表明:镀层中不同的复合颗粒和稀土两者对镀层的抗氧化能力均有影响。其小不同种类的颗粒对镀层抗氧化能力所产生影响的差别很明显;而稀土对镀层抗氧化能力影响的差别较小,且影响的程度比较接近。另外,两者影响的机理也不同。颗粒是通过分解、扩散等过程改变表面膜的组成来影响的,而稀土则是从提高膜的致密度和膜与基体的粘附性来影响的。作者认为,它们的影响既互相独立,而又互相补充。

The oxidized behaviours of three eletrodeposited Ni Matrix composite coatings Ni-B4C, Ni-TiC and Ni-ZrO2 -with and without the addition of rare earth have been investigated at 850℃. By using metallographic observation, ESCA and X-ray diffraction methods, experimental results show that both the composite particles and rare earth all have effects on anti-oxidized ability of coatings. The difference of the effects therein produced by various particles is evident, but the difference of the effects of rare earth on various coatings is small and relatively close. Furthermore, the mechanism of both effects is different too. Effects of the particles are carried out by decomposition and diffusion to change the composition of the surface film, but the effects of rare earth are carried out by the improvement of the meticulous degree and adherence of the film. The authors believe that the effects of particles and rare earth are independant of but complementary to each other.