(1. 南京航空航天大學(xué) 機(jī)電學(xué)院，南京 210016；
2. 中國直升機(jī)設(shè)計(jì)研究所，景德鎮(zhèn) 333001)
摘 要: 采用以酒石酸鈉為成膜劑的電解體系對(duì)0.5 mm厚的TB8鈦合金薄板進(jìn)行陽極氧化處理，采用掃描電鏡(SEM)觀察疲勞斷口及氧化膜的顯微形貌，采用X射線衍射儀(XRD)、能譜分析儀(EDS)對(duì)覆在鈦合金基體上的陽極氧化膜進(jìn)行物相分析，研究以酒石酸鈉為成膜劑的TB8鈦合金薄板陽極氧化疲勞斷裂機(jī)理。結(jié)果表明：陽極氧化處理后，表面形成了一層厚2 μm左右的均勻致密的氧化膜，氧化膜主要由金紅石型與銳鈦型TiO2混合晶體組成；陽極氧化處理可有效去除表面缺陷，降低了裂紋源的萌生及疲勞裂紋的擴(kuò)展速率，使疲勞條紋更加均勻細(xì)致；以酒石酸鈉為成膜劑制備的TB8鈦合金薄板經(jīng)陽極氧化處理，在疲勞壽命為1×104下，其疲勞強(qiáng)度相對(duì)于母材的提高了44%左右。
關(guān)鍵字: TB8鈦合金；陽極氧化；疲勞性能；斷口形貌
（1. College of Mechanic and Electronic Engineering, Nanjing University of Aeronautics and Astronautics,
Nanjing 210016, China;
2. China Helicopter Research and Development Institute, Jingdezhen 333001, China）
Abstract:Anodic oxidation of 0.5 mm-thickness TB8 titanium alloy sheet in the electrolyte system with sodium tartrate as film-forming agent was investigated. The microstructures of the fatigue fracture and the anodic oxide films were observed by scanning electron microscopy (SEM). Meanwhile, the phase composition of the oxide films on the titanium alloy substrate was determined by X-ray diffractometry (XRD) and energy dispersive spectrometry (EDS).The fatigue fracture mechanism of both unanodized and anodized TB8 titanium alloy sheet was investigated in the film-forming agent of sodium tartrate. The results show that, a uniform dense oxide film about 2 μm-thickness forms on the surface after anodic oxidation, the coating is composed of rutile TiO2 and anatase TiO2. The surface defects are eliminated effectively, the initiation and propagation rate of the crack source reduce, resulting in the fatigue striations more uniform and detailed. The fatigue strength of TB8 titanium alloy sheet after anodic oxidation in the film-forming agent of sodium tartrate, increases by about 44%, compared with the base metal at the fatigue life of 1×104 cycles.
Key words: TB8 titanium alloy; anodic oxidation; fatigue property; fracture morphology
