铬镀层结构转变的氢效应

THE EFFECT OF HYDROGEN ON THE STRUCTURAL TRANSFORMATION OF ELECTROPLATING CHROMIUM COATINGS

研究了常规六价铬镀铬并同时渗氢对镀层组织结构的影响。发现常规的薄镀铬层是一种不稳定的非晶态结构,在特定的渗氢条件下可以转变为稳定的非晶态结构或微晶结构。

The effect of hydrogen on the structural transformation of Cr coatings plated from the normal six valence chromium bath was studied by a method combined electroplating Cr with penetrating hydrogen.An unsteady amorphous Cr coating was obtained under the normal condition of plating Cr without penetrating hydrogen,at current density 20A/dm2 and bath temperature 60℃,plated for 15min..A steady amorphous Cr coating was obtained when electroplating and penetrating hydrogen were progressed simultaneously,both at current density 20A/dm2 and temperature 60℃,electrolyzed for 15 min..A microcrystlline Cr coating was obtained when penetrating hydrogen was preferably progressed for 1 hour,then electroplating and penetrating hydrogen were progressed at same time for 15 min,all at current density 20A/dm2 and temperature 60℃.It was analysed that the penetrating hytrogen can change the amount of the absorbed hydrogen on the plating surface and the steady amorphous Cr coating can be obtained only when the absorbed hydrogen on the plating surfact keeps a certain amount.