Ni-Al-W活性材料的界面扩散动力学

采用粉末冶金法制备Ni-Al-W活性材料Ni37.5 Al42.5 W20,研究了材料中Ni-Al、Al-W、Ni-W 3种不同界面处的扩散动力学.结果表明:在400℃保温不同时间下该材料表观激活能变化不大;扩散层厚度Δx随时间t的增加而增加,且lnΔx与lnt呈线性关系,在3种不同界面处只发生了扩散而未产生金属间化合...

Interfacial diffusion kinetics of Ni-Al-W active materials

Ni-Al-W active material Ni_37.5Al_42.5W₂₀ was prepared by powder metallurgy method, and the diffusion kinetics of Ni-Al, Al-W and Ni-W interfaces in the material were studied. The results show that the apparent activation energy of the material has little change when annealing at 400 ℃ for different time. The thickness of diffusion layer Δx increases with the increase of time t, and lnΔx has a linear relationship with lnt, but no intermetallic compounds are produced. The relationship between the Ni-Al interface layer thickness and annealing time is Δx_Ni-Al=4.5210^-8t^1/2.635, the interface diffusion mode is volume diffusion in lattice. The relationship between the Al-W interface layer thickness and annealing time is Δx_Al-W=9.5610^-8t^1/4.050, the interface diffusion mode is surface diffusion. The relationship between the Ni-W interface layer thickness and annealing time is Δx_Ni-W=2.3310^-7t^1/6.534, the interface diffusion mode is surface diffusion.