电沉积Fe-P非晶镀层的受热转变

Transformation of electrodeposited Fe-P amorphous coatings during process of heat-treatment

采用电沉积工艺制备了Fe-P非晶镀层,并研究了Fe-P非晶镀层在加热过程中镀层结构与硬度的变化趋势,结果表明:该镀层在300℃左右开始晶化,在330℃左右Fe-P合金开始转变为-αFe(P)固溶体,到370℃左右铁磷化合物FexP(x=1,2,3)从α-Fe(P)固溶体中脱溶析出,由于固溶强化和弥散强化的作用导致镀层硬度增大,并在370℃达到最大值,当热处理温度继续增高至460℃后,镀层中弥散相粒子逐渐长大,即发生Ostwald熟化现象,从而导致镀层硬度快速下降。

Fe-P amorphous coatings were prepared by electrodeposition, and the transformation of structure and hardness of the coatings after heattreatment at different temperatures were investigated. The results show that Fe-P amorphous coating begins to crystallize when heated at 300℃, α- Fe（P） solid solution appears when heated at 330℃, and Fe, P（ x = 1,2,3） compound separates out from the solid solution when heat-treatment temperature is up to 370℃. During the process of heat-treatment, hardness of the Fe-P coatings increases due to strengthening of solid solution and dispersed phase in the coatings, and the hardness reaches the maximum at 370℃. When heat-treatment temperature is higher than 460℃, dispersed phase in the coatings grows up, which is called Ostwald coarsening phenomenon, and hardness of the coating decreases quickly.