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利用双层辉光等离子渗金属技术,在20号钢表面进行钨-钼-钇和钨-钼共渗,并获得合金渗层。利用扫描电镜(SEM)和能谱仪(EDS)进行微观组织分析和成分分布检测,用X射线衍射仪(XRD)进行结构分析,用Fick第二扩散定律分别计算上述二元共渗和三元共渗渗层的钨、钼扩散系数以及扩散激活能。研究表明:钨-钼-钇和钨-钼共渗渗层组织均为柱状晶,渗层与基体之间有一条分界线。稀土钇的加入细化了渗层的组织;钨-钼-钇共渗层物相主要为:Fe(W,Mo,Y),Fe3Mo,Fe17Y2,W,Y等;钨-钼共渗渗层物相主要为:Fe(W,Mo);钇的加入使渗层中钼在距表面12~15,24~25,35~36μm处的扩散系数分别提高了1.72,1.85,2.10倍,平均增大1.89倍。而钨原子的扩散系数在加入稀土元素后减小了0.92,0.99,0.76,平均降低了0.89倍;稀土钇的加入降低了钼原子的扩散激活能,说明了稀土钇对钼具有催渗作用,但对钨没有催渗作用。
Tungsten-molybdenum-yttrium and tungsten-molybdenum co-permeation was achieved on the surface of No. 20 steel by double glow plasma infiltration metal technology, and the alloy infiltrated layer was obtained. The microstructure and composition distribution of the samples were analyzed by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The structures of the samples were analyzed by X-ray diffraction (XRD). The binary diffusion and ternary Infiltration of tungsten, molybdenum diffusion coefficient and diffusion activation energy. The results show that the microstructure of tungsten - molybdenum - yttrium and tungsten - molybdenum infiltration is columnar crystal, and there is a dividing line between the infiltrating layer and the matrix. The addition of rare earth yttrium refined the microstructure of the infiltrated layer. The main phases of the tungsten-molybdenum-yttrium common doped layer were Fe (W, Mo, Y), Fe3Mo, Fe17Y2, W, Y and so on. The main phases are Fe (W, Mo). The addition of yttrium increases the diffusivities of molybdenum in the infiltrated layer by 12.7, 18.5 and 25.5 times from the surface at 12-15, 1.89 times larger. However, the diffusion coefficient of tungsten atoms decreased by 0.92, 0.99 and 0.76 after adding rare earth elements, and decreased by an average of 0.89 times. The addition of rare earth yttrium reduced the diffusion activation energy of molybdenum atoms, However, there is no role of reminding tungsten infiltration.