纯钛不同温度热氧化处理组织与耐蚀性研究

纯钛不同温度热氧化处

理组织与耐蚀性研究 Document number：PBGCG-0857-BTDO-0089-PTT1998

学号：05430205

江苏工业学院

毕业论文

（2009届）

题目纯钛不同温度热氧化处理组织与耐蚀性研究

学生倪静

学院材料科学与工程学院专业班级金材052 校内指导教师胡静专业技术职务教授

二○○九年六月

纯钛不同温度热氧化处理组织与耐蚀性研究

摘要：钛及钛合金由于其高的比强度、优异的耐腐蚀性和良好的生物相容性，广泛应用于航空航天、化工、航海、医疗器械、国防领域。但钛及钛合金在一些介质中较差的耐腐蚀性限制了它的应用。热氧化处理是一种简单、环保的工艺，可强化钛合金的表面，改善钛在一些介质中的耐腐蚀性能。

本研究选取了TA2为研究对象，将TA2置于箱式电阻炉中进行温度为500℃、600℃、650℃、700℃、750℃和850℃，时间为210min热氧化。利用光学显微镜（OM）对不同温度热氧化试样表层和截面的组织分析；用扫描电子显微镜（SEM）对不同温度热氧化试样的表层和截面、腐蚀前后进行组织形貌进行分析；利用EDS 分析了微区成分和截面元素分布情况；采用X射线（XRD）对不同温度热氧化试样的表层进行物相分析；利用维氏硬度计对不同温度热氧化试样的表层进行显微硬度分析。最后研究了TA2经不同温度热氧化后在36-38%的HCl和30%的H2O2中的耐腐蚀性。

研究结果表明，600℃以上热氧化在表面形成了TiO2氧化膜，整个氧化渗层由表层TiO2氧化膜和氧扩散层构成，热氧化温度越高，表面形成的TiO2氧化膜越厚，表面硬度越高。热氧化后试样表面硬度随温度升高而提高；耐腐蚀性在一定温度范围内，随温度升高而提高，本研究中，210min、700℃生成的氧化膜的耐腐蚀性最好。

关键词：纯钛；热氧化；氧化层；显微硬度；耐腐蚀性

The effect of thermal oxidation at different temperature on the microstructure and corrosion-resistance for CP-Ti Abstract: Titanium and its alloys have a wide range of applications in the fields of aerospace，chemical industry，marine，biomedical devices and defense because of their combination of properties in terms of high strength to weight ratio, exceptional resistance to corrosion and excellent biocompatibility.However, the poor tribological properties and undesirable corrosion-resistance in certain mediums of titanium alloys are still a limit for their use in some applications. Thermal oxidation (TO) treatment is an easy and environmental friendly technique that can be used to harden the surface of titanium alloys， and hence improve the poor tribological properties of these materials.

TA2 samples were subjected to TO treatment at 500℃、600℃、650℃、700℃、750℃、850℃ for 210min. The effects of different TO temperature on microstructure、hardness、corrosion resistance in 36-38% HCl、30% H2O2 of TA2 were systematically studied. OM， SEM&EDS， XRD etc were employed for the microstructure, morphology and phases analysis; The hardness was measured by Vickerhardness tester. As reference, all the tests above were carried out on untreated TA2 as both counterparts.

The results showed that the hardness of TA2 surface increases accompanied by significant improvement in wear resistance. The higher the TO temperature is，the thicker the oxidized film is. The oxidized film consists of titanium dioxide layer and oxygen diffusion zone beneath it. The best corrosion resistance was obtained after 210min700℃TO treatment.

Key words: CP-Ti；Thermal oxidation；Oxidation layer；Micro-hardness；Corrosion-resistance