电沉积Ni81.32Mo18.68非晶/纳米晶镀层的晶化动力学

在碱式碳酸镍为主的盐溶液中用电沉积法制备出含Mo原子分数为18.68%的Ni-Mo合金镀层. X射线衍射(XRD)表明该镀层为非晶/纳米晶混合结构; 用差示扫描量热法(DSC)对这种非晶/纳米晶混合结构的合金进行了晶化动力学研究, 测得其晶化激活能(E)为3.84×105 kJ·mol-1; 晶化开始温度约为440 ℃, 与非晶态结构Ni-Mo合金镀层相比, 晶化温度提高了约13 ℃. 热处理过程发现, 非晶/纳米晶混合结构镀层中少量纳米晶的存在阻止了非晶态相转变的可能性, 提高了混合结构镀层的热稳定性和晶化温度; 镀层在450 ℃热处理过程中有新相产生, 其不仅提高了镀层的密实度, 同时也阻止了非晶态相的转变, 提高了镀层的热稳定性.

Crystallization Kinetics of Electrodeposited Amorphous/Nanocrystalline Ni81.32Mo18.68 Alloy Coating

An electrodeposited Ni-Mo alloy coating with 18.68% (atomic fraction) Mo content was obtained in an alkaline nickel carbonate solution. It was found from X-ray diffraction (XRD) that the deposition was composed of amorphous and nanocrystalline phases and compounds. Crystallization dynamics fromdifferential scanning calorimetry (DSC) showed that the deposition crystallization activation energy (E) was about 3.84×105 kJ·mol-1 and the crystallization temperature was 440 ℃. Compared with amorphous Ni-Mo alloy depositions, the deposition crystallization temperature was increased by about 13 ℃. It was found from the heat treatment process that a small amount of nanocrystallines in the deposition could prevent the possibility of crystallization and improve the thermal stability and increase the crystallization temperature of the co-composite. New phases would take on in the deposited Ni81.32Mo18.68 alloy during the heat treatment process when annealed at 450 ℃. This improved the density of the deposition coating and prevented a change in the amorphous phase. The thermal stability of the co-deposited coating was also improved.