电解液组成及电参数对Ti_6Al_4V表面微弧碳氮化改性的影响

EFFECTS OF ELECTROLYTE COMPOSITION AND ELECTRICAL PARAMETER ON TITANIUM CARBONITRIDE FILMS BY PLASMA ELECTROLYTIC CARBONITRIDING OF Ti_6Al_4V ALLOY

采用电解液微弧碳氮化技术在Ti6Al4V合金表面合成了纳米结晶多微孔的Ti(CxN1-x)改性层,探讨了电解液组成及电参数对改性层形貌和相组成的影响。结果表明:增加电解液中甲酰胺的含量有助于Ti(CxN1-x)膜的生长,增加电解液中KCl的含量会加剧渗氢反应,导致TiH2的生成。电参数中电压是最重要的控制因素,降低电压、占空比或者提高频率均不利于Ti(CxN1-x)膜的形成。较佳的电参数是:电压600V、占空比40%、频率100Hz。

Porous nanocrystalline Ti（CxN1-x） films on a Ti6Al4V alloy surface were prepared in an electrolytic solution by plasma electrolytic carbonitriding （PECN） with a pulse power supply.The effects of electrolyte composition and electrical parameter on the morphologies and phase compositions of the modified layers were investigated.The results show that the increase of the formamide concentration in the electrolyte can favor the growth of the Ti（CxN1-x） films.The increase of potassium chloride can affect the permeation of hydrogen,leading to the formation of TiH2.The applied voltage is a dominant effect on the electrical parameters.The decrease of the applied voltage and duty cycle or the increase of the pulse frequency could have a negative effect on the development of Ti（CxN1-x） films.The applied voltage of 600 V,the duty cycle of 40% and the pulse frequency of 100 Hz were determined as the optimal electrical parameters according to the experimental results.