【作者】 张健；

【导师】 朱永福； 张继堂；

【作者基本信息】 吉林大学 ， 材料工程（专业学位）， 2020， 硕士

【摘要】 在金属材料领域,铜（Cu）由于其优良的导电导热性、机械加工性以及抗菌性而广泛应用于电子电器、家电机械和医疗设备领域之中。但在长期服役的过程中,由Cu及其合金制作的部件通常面临被氧化的问题。一般的抗氧化方法诸如表面钝化、电镀喷漆等都不可避免的带来酸碱废液、废渣等环境问题。近年来,有人提出通过在铜中添加少量合金元素并在惰性气氛中对其进行热处理的方法,在铜表面自生形成一层抗氧化薄膜从而达到阻止铜进一步被氧化的目的。该方法因其能有效提高铜的抗氧化能力且对环境没有破坏作用而备受人们的关注。钛（Ti）作为一种储量丰富的耐蚀金属,通常可作为合金元素与Cu形成合金使用。为改良铜合金氧化现象,优化处理工艺,本论文以添加少量合金元素Ti（0.2、0.5、1.0 wt.%）的Cu Ti合金作为研究对象,将其在氩氢混合保护气氛下进行退火处理。本文运用电子扫描电镜、热重分析等方法,对经过不同温度,不同时间退火处理后的合金样品的氧化行为进行了探讨。实验结果表明,通过添加少量Ti合金元素形成的Cu Ti合金,在保护气氛下经过退火工艺处理后,在合金表面生成了相对致密的金红石型的Ti O₂氧化膜。在1 atm氧气、400oC的氧化条件下,通过对比不同退火条件获得的Cu Ti样品的氧化增重曲线,我们发现,随着合金元素Ti含量的增加、退火温度的升高以及退火时间的延长,相对于纯铜,Cu Ti合金的抗氧化性能均逐渐得到提高。尤其当合金元素含量高于0.5 wt.%、退火温度超过800oC、退火时间超过12 h时,我们所获得的Cu Ti合金样品氧化后的增重幅度已不明显。经实验分析,退火后在表面形成的相对致密的金红石型Ti O₂保护膜对提高铜的高温抗氧化能力有明显的促进作用。此外,我们还研究了相同退火条件下,合金元素Al的添加对Cu Ti合金抗氧化能力的影响。研究发现,Al元素能诱导Ti O₂氧化膜的生成,降低其形成温度和时间,并在基体和金红石型Ti O₂之间,形成了Al的氧化物,阻碍了O元素与基体的接触,进一步地提高了Cu Ti合金的抗氧化能力。更多还原

【Abstract】 Pure copper（Cu）,because of its excellent conductivity,thermal conductivity,mechanical processing and antibacterial properties,is widely used in electronic appliances,household appliances machinery and medical equipment and some other fields.Howevet,during the process of long-term service,components made of Cu and its alloys are usually faced with the problem of oxidation.General anti-oxidation methods,surface passivation or electroplating paint,inevitably bring acid and alkali waste liquid,waste residue and other environmental problems.In recent years,a popular method has been put forward to improve oxidation resistance of copper with the formation of an anti-oxidation film on the surface of alloys by adding alloying elements and then proper heating treatment in inert atmosphere.An increasing attention has been paid to this method for it effectively improves the oxidation resistance and reduces environmental pollution.Moreover,as an abundant anti-corrosion metal,titanium（Ti）can also be utilized as an alloying element to add into Cu.In order to ameliorate the oxidation properties of copper alloys and optimize the treatment process,Cu Ti alloys added with a small amount of Ti（0.2,0.5,1.0 wt.%）were taken as the research object in this work and annealed in argon-hydrogen mixed protective atmosphere.Also,SEM,TG and other analytical methods were used to investigate the oxidation resistance of Cu Ti alloy samples annealed at different temperatures for different time.The experimental results show that after annealing treatment under a protective atmosphere,a relatively dense rutile-type Ti O₂ protective film is formed on the surface of the Cu Ti alloys with a small amount of Ti.Under the oxidation condition of 400oC and 1 atm O₂ pressure,the oxidation weight gain curves of Cu Ti samples annealed under different conditions were compared.It was figured out that with the increasing of Ti content,annealing temperature and the extension of holding time,the oxidation resistance of Cu Ti alloys was gradually improved compared with pure copper.Especially,the Cu Ti alloy samples with content higher than 0.5 wt.%have almost no obvious weight gain when they are annealed above 800oC for over 16 h.This manifests again that the relatively dense rutile-type Ti O₂ oxide film formed on the surfaces of alloys after proper annealing procedure can obviously improve the oxidation resistance of Cu at elevated temperature.Under the same annealing condition,furthermore,the effect of Al on the oxidation resistance of Cu Ti alloy has also been discussed in this study.It was found that Al element is able to induce the formation of Ti O₂ oxide film,which reduces its formation temperature and time.Besides,there are Al oxides formed between the matrix and rutile-type Ti O₂,which effectively obstructs the contact between O element and the matrix,further improving the oxidation resistance of Cu Ti alloys.更多还原