阳极氧化膜厚度对TB8钛合金表面特性及其粘结性能的影响

采用以酒石酸钠为主盐的电解体系对TB8钛合金进行阳极氧化,研究阳极氧化膜厚度对TB8钛合金表面特性及其与环氧树脂粘结性能的影响。采用SEM、XRD和EDS分析了阳极氧化膜的微观形貌和晶体结构,采用角接触测量仪和三维视频显微镜分别对阳极氧化膜的表面润湿性和粗糙度进行测量。研究了不同厚度TB8钛合金阳极氧化膜的粘结性能与表面形貌、相组成、润湿性及粗糙度的关系。结果表明:采用以酒石酸钠为主盐的电解体系对TB8钛合金进行阳极氧化处理,氧化时间为15 min,电压为1~30 V时,能够在钛合金表面形成一层1~4μm厚的阳极氧化膜;氧化膜主要由金红石型和锐钛型TiO₂混合晶体组成,其表面具有微纳多孔的粗糙结构;随着厚度的增加,阳极氧化膜对水的润湿性能逐渐增强。当氧化膜厚度为3μm时,可获得最大粘结强度为19.6 MPa,相对于母材提高了88.5%,同时,水接触角为43.2°,相对于其母材减少了56.1%;粗糙度为2.14μm,相对于母材提高了137.8%。

Effects of anodic oxide film thickness on surface characterization and adhesive strength of TB8 titanium alloy

The TB8 titanium alloy is anodized in the sodium tartrate electrolyte to investigate the effects of anodic oxide film thickness on the surface characterization and adhesive strength between the anodic oxide nanostructures and the epoxy resin. SEM, XRD and EDS are used to evaluate the morphology and crystalline structure of the anodic oxide films. The wettability and roughness of the anodic oxide films are measured using a contact angle meter and a digital video microscope. The correlation between the adhesive strength, surface morphology, phase composition, roughness and wettability of the anodic oxide film of TB8 titanium alloy is investigated. The results show that an anodic oxide film about 1-4 μm thick is formed on the surface after anodic oxide in the sodium tartrate electrolyte at the voltage of 1-30 V for 15 min. The anodic oxide film, which is mainly composed by rutile TiO₂ and anatase TiO₂, has a micro-and nano-porous rough structures and the wettability of water increases with the increase of the anodic oxide film thinkness. The maximum shear strength (19.6 MPa) is obtained when the thickness of the anodic oxide film is about 3 μm, which is improved by 88.5%, and the water contact angle is 43.2°, decreased by 56.1%; the surface roughness is 2.14 μm, improved by 137.8%.