可控气氛喷涂钛涂层及涂层电化学性能

Electrochemical performance of Ti coating by controlled atmosphere thermal spraying

为了研究在低度真空环境中所获得的钛涂层的组织和性能,以氩气为载气,在压力为0.4MPa、载气温度为室温、不同的喷涂条件下,用热喷涂方法在Q235钢基体上制备了钛金属涂层.经扫描电子显微镜(SEM)观察,发现在真空中用氩气为载气喷涂的钛涂层组织致密,缺陷与孔隙相对较少.x-射线衍射分析仪(XRD)分析表明,在空气中喷涂的钛涂层有较多的氧化物和氮化物;在真空中喷涂的钛涂层基本上没有氧化物和氮化物,其衍射图谱与纯钛十分接近;在空气中用氩气为载气喷涂的钛涂层含有一些氧化物,涂层中的缺陷和孔隙数量介于前两种状态之间.采用动电位极化法研究了在不同条件下热喷涂钛涂层的电化学腐蚀行为,并与纯钛试样进行比较.结果表明:在真空条件下喷涂的钛涂层腐蚀电位高于在空气中喷涂的钛涂层和在空气中用氩气为载气喷涂的钛涂层,但略低于纯钛的腐蚀电位.

In order to investigate the microstructure and properties of Ti coating prepared in low vacuum atmosphere,Ti coating was deposited on Q235 steel substrate using thermal spraying technique under the argon gas pressure of 0.4MPa and different thermal spraying conditions. It is noted through the SEM observation that the microstructure of the Ti coating sprayed in low vacuum is dense,and both porosity and defect in the coating are fewer. The XRD analysis shows that the Ti coating prepared in air contains much more oxide and nitride,while almost no oxide and nitride can be noted in the Ti coating prepared in vacuum. Some oxides can be observed in the Ti coating sprayed in argon,where the amount of porosity and defect is intermediate between that in the Ti coatings sprayed in air and in vacuum. In addition,the electrochemical behavior of the Ti coating prepared under different spraying conditions was analyzed,and compared with that of pure titanium. The results show that the corrosion potential of the Ti coating sprayed in vacuum is much higher than one of the Ti coatings sprayed in air and in argon,but a little lower than one of pure titanium.