Ni－B超细非晶合金的化学制备、反应机理及性质研究

AN INVESTIGATION OF CHEMICAL PREPARATION,REACTION MECHANISM AND THE PROPERTIES OF Ni-B ULTRAFINE AMORPHOUS ALLOY

本文研究了水溶液中ＮｉＣｌ２与ＫＢＨ４的反应及其产物Ｎｉ－Ｂ超细非晶合金的性质，详细探讨了反应的电化学基础和反应过程及机理．发现Ｎｉ（２＋）与的反应由三个独立的基本反应组成，其中不可避免地存在的分解即与Ｈ２Ｏ的反应，Ｎｉ－Ｂ则产生于Ｎｉ（２＋）的还原（被）和离子内部的氧化还原反应．反应中，反应液的ｐＨ值可自动恒定在３．１８左右．在总包反应中，完全还原１ｍｏｌＮｉ（２＋）需要消耗１．８４ｍｏｌ，其中的分解反应约占４８％．根据反应机理可计算产物的组成，计算结果与实际测定值完全一致．电镜测定表明，反应产物呈非晶态，粒径约４００．

his paper reports the results of our studies on the reaction between NiCl2 and KBH4 in aqueous solution and the properties of the reaction product, Ni-B ultrafine amorphous alloy.The reaction procedure and the mechanism as well as the electrochemistry of the reaction are discussed in detail. It was found that the reaction of Ni(2+) and in aqueous solution can be divided into three independent elementary reactions, one of which is the hydrolysis of . The product Ni-B alloy is produced through the reduction of Ni(2+) by and the disproportionation of (the reduction of B(+3) by H- in ). The pH value of the reaction mixture remains at about 3.18 throughout the reaction. For the complete reduction of 1 mole of Ni(2+), about 1 .84 moles of are needed, in which 48% are actually hydrolyzed. The composition of the Ni-B product can be predicted according to the reaction mechanism we proposed and the results are in good agreement with the experimental values determined by ICP. Electron diffraction and transmission electron microscopy show that the Ni-B product is in the amorphous state with average particle size of about 400.