Fe粉表面化学镀Ni-P的热力学与动力学

为了改善粉末的表面性状、提高其耐腐蚀及耐磨损性能、降低烧结温度,文中用化学镀法在Fe粉表面包覆了低熔点的Ni-P合金镀层.为了更好地控制粉体化学镀的沉积速率及探讨其沉积机制,引入电化学Bockris方程式、用称量法测定Fe粉表面镀层的沉积量,根据热力学基本方程式求得了热力学函数ΔG㈠dep,ΔS㈠dep,ΔH㈠dep,...

Thermodynamics and kinetics of electroless Ni-P plating on Fe powder

In order to improve the properties of Fe powder such as inoxidability and abrasion resistance,and drop the sintering temperature,the electroless Ni-P plating on Fe powder was prepared successfully.Bockris equation of the electrochemistry was applied to the thermodynamics of Fe powder electroless Ni-P plating for controlling its deposit rate and deposit mechanism.The thermodynamics functions ΔGdepΘ,ΔSdepΘ and ΔHdepΘ were figured out by studying the deposit amount of coating.In addition,the experiential equation of electroless deposition was established.The results show that the optimal temperature of electroless plating is 362 K.If it is higher than such temperature,the plating liquor may easily decompose.Within the range of optimal temperature,the chemical reaction can occur spontaneously.The reaction of this system is endothermic.