关键词: 电镀, 镍铁, 分析, 穆斯堡尔谱法

The formation process of electrodeposited NiFe alloy, the influence of cationic impurities Al3+, Mn2+, Cr3+, Zn3+ and Cu3+ in the bath on the composition and texture of plating layers and the texture and corrosion resistance of electrodeposited NiFe alloy at various ways of chromium treatment were investigated by Mossbauer spectroscopy. The results obtained are as follows: (1) Under normal operating conditions, only a single γ-NiFe phase plating layer was found in the process of Ni75Fe25 electroplating. (2) The formation of the lamellar microstructure is a consequence of the periodic incorporation of minor amount of organic additives with NiFe alloy in the plating layer. (3) As the concentration of cationic impurites Al, Cr, Mn, Zn and Cu presented in the bath exceeds 10-2M, it is found that the grain size of the plating layer increases and the crystal shows preferential orientation. Some cationic impurities may cause local environmental effect and change the angle between the direction of a magnetic field and the direction of the emitted γ-ray. (4) In order to improve the corrosion resistance of electrodeposited NiFe alloys, a NiFe/conventional chromium plating is preferable to a NiFe/microporous chromium plating.

Key words: ELECTROPLATING, FERRONICKEL, ANALYSIS, MOSSBAUER SPECTROMETRY