【摘要】：為了滿足鈦及鈦合金在航空航天、船舶制造、生物醫(yī)學(xué)、生活等領(lǐng)域中的廣泛應(yīng)用,且減少由于腐蝕而產(chǎn)生的損耗,提高鈦及鈦合金的耐腐蝕性能及改善表面性能,達(dá)到高效性生產(chǎn)、長久性使用的目的,本文以TA2工業(yè)純鈦為實(shí)驗(yàn)樣品,以0.5mol/L的硫酸為電解液,采用陽極氧化的表面改性處理方法,研究了陽極氧化的工藝流程及其影響參數(shù),并且通過大量的實(shí)驗(yàn)確定了工藝參數(shù)電壓、時(shí)間、溫度對氧化膜層表面宏觀特征、顯微組織特性及耐腐蝕性能的影響。其次,在一次陽極氧化所得樣品的基礎(chǔ)上,再次施加高電壓進(jìn)行第二次陽極氧化,并且研究了經(jīng)二次陽極氧化后試樣的微觀形貌特征、化學(xué)組成及耐蝕性能。陽極氧化工藝的實(shí)驗(yàn)結(jié)果表明:在優(yōu)化的工藝參數(shù)和控制條件下,獲得的TA2陽極氧化膜層能呈現(xiàn)五彩斑斕的顏色,且色澤均勻、鮮亮。膜層組織具有較好的穩(wěn)定性,結(jié)構(gòu)致密,且抗腐蝕性能得到顯著的增強(qiáng),陽極氧化在一定程度上實(shí)現(xiàn)了材料功能性與美觀性的統(tǒng)一。此外,該工藝操作簡單且極具效果,能滿足金屬表面陽極氧化改性處理及工程化實(shí)際生產(chǎn)應(yīng)用的要求。陽極氧化工藝條件(電壓、時(shí)間、溫度)對著色膜層的性能起著非常重要的作用,其中電壓是最重要的影響因素。隨著電壓的改變,氧化膜層的厚度發(fā)生變化,由于光的干涉作用使膜層色澤呈規(guī)律性的變化。在適當(dāng)?shù)臅r(shí)間和溫度下,膜層表面隨電壓的升高變的更加致密、平整,并均勻的覆蓋在基體上,對金屬基體起著很好的保護(hù)作用,腐蝕介質(zhì)由于由于膜層的屏障作用對金屬的腐蝕能力減弱。在同樣的電壓和溫度下,改變時(shí)間,膜層色澤率變化不大,但當(dāng)時(shí)間超過30min,膜層會出現(xiàn)“起粉”現(xiàn)象,導(dǎo)致膜層色澤不均勻。當(dāng)時(shí)間超過1Omin,膜層的致密度和耐腐蝕性會隨著時(shí)間的延長下降。當(dāng)溫度超過40℃,膜層開始出現(xiàn)“起粉”現(xiàn)象,隨著溫度的繼續(xù)升高,膜層表面微孔數(shù)量增多且耐腐蝕性能下降。當(dāng)溫度低于20℃,由于溫度的降低會影響原子和離子的擴(kuò)散速度,導(dǎo)致陽極氧化進(jìn)程變得緩慢,效率降低。因此,可以得出最佳時(shí)間為5min-10min,最佳溫度為20℃-30℃,對于電壓可根據(jù)具體需要進(jìn)行選擇。對TA2工業(yè)純鈦進(jìn)行恒電位模式二次陽極氧化,分別采用掃描電子顯微鏡(SEM)、X射線光電子能譜(XPS)及電化學(xué)工作站研究膜層表面色澤、形貌特征、成分及其動電位極化曲線。研究結(jié)果表明:二次陽極氧化促使膜層在一次陽極氧化的基礎(chǔ)上再次生長,導(dǎo)致膜層厚度增加,膜層色澤進(jìn)一步加深。TA2工業(yè)純鈦經(jīng)過陽極氧化所得到的氧化膜層均為多孔形貌,經(jīng)二次陽極氧化后形成的膜層,表面形貌更加致密平整,微孔數(shù)量進(jìn)一步減少;二次陽極氧化所獲得的膜層較一次陽極氧化含有更多穩(wěn)定性的金紅石型TiO2,膜層表面活性降低,自腐蝕電流密度下降,耐腐蝕性得到較大的提升。
[Abstract]:In order to satisfy the extensive application of titanium and titanium alloys in aerospace, shipbuilding, biomedicine, life and other fields, and reduce the loss caused by corrosion, improve the corrosion resistance and surface properties of titanium and titanium alloys, To achieve the purpose of high efficiency production and long-term use, the surface modification method of anodic oxidation was adopted in this paper, in which TA2 industrial pure titanium was used as experimental sample and 0.5mol/L sulfuric acid as electrolyte. The technological process and its influence parameters of anodic oxidation were studied. The effects of process parameters, such as voltage, time and temperature, on the surface macroscopical characteristics, microstructure and corrosion resistance of the oxide film were determined by a large number of experiments. Secondly, on the basis of the sample obtained by primary anodization, the second anodization was carried out by applying high voltage again, and the microstructure, chemical composition and corrosion resistance of the sample after secondary anodization were studied. The experimental results of anodic oxidation process show that the TA2 anodic oxide film can show colorful color under the optimized process parameters and control conditions, and the color is uniform and bright. The structure of the film is relatively stable, the structure is compact, and the corrosion resistance is obviously enhanced. To some extent, the anodization realizes the unification of the functional and aesthetic properties of the material. In addition, the process is simple and effective, and can meet the requirements of anodic oxidation modification of metal surface and practical application of engineering. Anodic oxidation process conditions (voltage, time, temperature) play a very important role in the performance of colored film, among which voltage is the most important factor. The thickness of the oxide film changes with the change of voltage, and the color of the film changes regularly due to the interference of light. At the appropriate time and temperature, the film surface becomes denser, flatter, and more evenly covered on the substrate with the increase of voltage, which plays a good protective role on the metal substrate. The corrosion resistance of the corrosion medium to metals is weakened due to the barrier effect of the film. Under the same voltage and temperature, the color rate of the film will not change much when the time is changed, but when the time exceeds 30 min, the phenomenon of "powdering" will appear, which will lead to the uneven color of the film. When the time exceeds 1 O min, the density and corrosion resistance of the film will decrease with the prolongation of time. When the temperature is above 40 鈩，

本文編號：2384300