目的 研究一种钛合金化学转化工艺,增强钛合金表面防护能力及其与涂层的结合能力。 方法通过单因素实验确定 TC1 钛合金氟化物-磷酸盐转化工艺,采用 SEM,EDS,XRD 分析膜层的微观形貌及成分,同时测试转化膜的有关性能。 结果 在 Na3PO4 40 g/ L,NaF 15 g/ L,酸度调节剂 A 25 mL/ L,pH 控制在 4. 4 ~4. 6 之间,温度 30 ℃条件下,可在 TC1 钛合金表面获得均匀一致的灰色转化膜。 转化膜由许多细小的球状晶粒组成,主要相成分为 Na3TiOF5 及 Na2TiF6。 转化膜的摩擦系数仅为 0. 3 ~ 0. 5,明显低于 TC1 基体。 转化膜与 TB06-9 底漆的干性附着力为0 级,浸泡48 h 后的湿态附着力仍可达1 级,远远好于 TC1 基体。 结论 氟化物-磷酸盐转化膜可以降低 TC1 钛合金的摩擦系数,提高其与有机涂层的附着力。

Objective A chemical conversion technique was researched to enhance the protective ability of titanium alloy surface and the adhesion between titanium alloy and organic coating. Methods The preparation technique of fluoride-phosphate conversion coating formed on TC1 alloy was determined by the single-factor experiments. The microstructure and composition of conversion coating were analyzed by SEM, EDS and XRD. Besides, the related properties of the conversion coating were researched. Results A uniform, coherent and gray conversion coating could be obtained on the surface of TC1 alloy when Na3PO4, NaF, Acidity Regulator A, pH and temperature were 40 g/ L, 15 g/ L, 25 mL/ L, 4. 4 ~4. 6 and 30 ℃, respectively. The microstructure of the coating showed many small spherical grains. The main phase components were Na3TiOF5 and Na2TiF6. The friction coefficient of the fluoride-phosphate conversion coating was only 0. 3 ~0. 5, which was significantly lower than that of TC1 alloy. The dry adhesion level between conversion coating and TB06-9 organic coating was 0, and the wet adhesion level after 48 h immersion could still reach 1, both were far better than those of the TC1 alloy substrate. Conclusion Fluoride-phosphate conversion coating could reduce the friction coefficient TC1 titanium alloy, and improve the adhesion between TC1 alloy and organic coating.