Mo-MoSi2梯度层的制备及显微组织腐蚀方法

Preparation of Mo-MoSi_2 gradient layer and etching method for its microstructure

以Mo为基体,利用KCl-NaCl-NaF-SiO2熔盐体系电沉积出的硅作为渗硅硅源,电沉积硅和在Mo基体上渗硅同时进行,制备出了Mo-MoSi2梯度层,并对该梯度层显微组织腐蚀方法进行了研究。结果表明,Mo-MoSi2梯度层硅、钼含量呈渐变形式,在靠近试样表面部分,硅含量沿深度下降率较大;中间部分,硅含量基本保持不变;在梯度层靠近Mo一侧,硅含量的下降速率介于前两者之间;用氢氟酸10 mL、硝酸20 mL、40 mL的蒸馏水构成的腐蚀剂,硝酸12 mL、氢氟酸12 mL、甘油18 mL构成的腐蚀剂对纯钼板断面显微组织腐蚀效果良好;用过二硫酸铵15 g、蒸馏水100 mL构成的腐蚀剂对纯钼板表面显微组织腐蚀效果较好;用硝酸12 mL、氢氟酸12 mL、甘油18 mL构成的腐蚀剂对Mo-MoSi2梯度层断面显微组织腐蚀效果好。

Mo-MoSi2 gradient layer was made on Mo substrate using silicon electrodeposition in KCl-NaCl-NaF-SiO2 mixed salt system as silicon source and the etching method for microstructure of Mo-MoSi2 gradient layer were researched. The results are as following, the silicon content in gradient layer appears three changing regularity. The silicon content declines rapidly along depth direction near the gradient layer surface. The silicon content is almost invariable in middle section of gradient layer. The declining rate of silicon content is slow comparatively in the section near Mo substrate. The effect of etching to Mo sheet cross section microstructure by the agent made of hydrofluoric acid 10 mL, nitric acid 20 mL and distilled water 40 mL, or the agent made of hydrofluoric acid 12 mL, nitric acid 12 mL and glycerin 18 mL is very good. The effect of etching to Mo sheet surface microstructure by the agent made of peroxysulphuric ammonium 15 g and distilled water 100 mL is better. The effect of etching to Mo-MoSi2 gradient layer cross section microstructure by the agent made of hydrofluoric acid 12 mL, nitric acid 12 mL and glycerin 18 mL is also good.