沉积温度对渗钽层组织与耐蚀性能的影响

<正> 钽是一个负电性强的金属,其平衡电位相当低(E_(Ta/Ta_2O_3)=-0.81V),无论是在氧化性的还是在还原性的含氯化物的酸中(即使氧含量很小)都能生成致密的氧化膜(Ta_2O_5),这种膜的粘着性能好,牢固且稳定,在低于260℃的温度下有很好的保护性。由于钽的提炼和加工困难,价格昂贵。因此,研究和开发渗钽技术有它重要的实际意义。

EFFECT OF DEPOSIT TEMPERATURE ON MICROSTRUCTURE AND CORROSION RESISTANCE OF TANTALUM COATING

The effect of different deposition temperature (1173-1333K) on thickness, hole ratio, phase componets, morphology of surface and corrosion resistance of deposited tantalum layer on low carbon steel was investigated by means of metallographical technique, microhardness testing, X-ray diffraction analysis, scanning electron microscope analysis and corrosion weight loss test. The experimental results showed that the tantalum coating of steel was composed of Ta and Fe_5Ta_3 phases, and with the increase of deposition temperature from 1173K to 1333K, the grain size as well as the thickness of coating layer increased notably. Under 1283-1333K, a denser, thicker tantalum coating could be obtained. The corrosion rate of Ta-coated steel in 37%HCl solution is 2-3 orders lower than that of uncoated steel.