C17200铍铜合金表面等离子制备Ta涂层的组织及耐腐蚀性能

用双层辉光等离子渗金属技术在C17200铍铜合金表面制备Ta涂层，以提高其抗腐蚀性能。用X射线衍射仪、扫描电子显微镜、划痕仪等分别研究Ta涂层组织结构、成分以及与基体的结合强度，并用三电极体系测量C17200合金及其制备Ta涂层后的腐蚀性能。研究表明，保温0.5~3 h后，在C17200表面形成表面Ta沉积层/Ta-Cu-Be过渡层的复合Ta涂层，该复合涂层由Ta、Ta₂Be、Cu （Be）等相组成。涂层由岛状组织融合生长，Ta涂层随保温时间的延长而增厚。保温2 h的Ta涂层表面平整致密，与基体结合良好，在10% H₂SO₄溶液中较未处理C17200基材的自腐蚀电位升高，自腐蚀电流下降，腐蚀速率降低，表现出良好的耐蚀性能，有效地保护铍铜基体不受腐蚀液侵蚀。

Microstructure and Corrosion Resistance of Plasma Ta-coated C17200 Beryllium Copper Alloy

In order to improve the corrosion resistance, Ta coatings were prepared on C17200 beryllium copper alloy by double glow plasma surface alloying technology. The microstructure, composition of the Ta coatings and the bond strength between Ta coating and substrate were analyzed by X-ray diffraction, scanning electron microscopy and scratch tester respectively. The corrosion properties of Ta-coated samples and C17200 alloy were measured by the standard three-electrode system. The results show that a Ta deposition layer/Ta-Cu-Be diffusion layer is formed on C17200 alloy after depositing Ta coating for 0.5-3 h, and it is composed of Ta, Ta₂Be, Cu(Be) etc. Ta coatings are formed by the island growth mode, and the coating thickness increases with the alloying time. The coating alloyed for 2 h is compact, smooth and well bonded with the substrate, exhibiting a good corrosion resistance due to the higher self-corrosion potential, lower self-corrosion current and corrosion rate, which effectively protects the beryllium copper substrate from erosion.