【作者】 张跃飞；

【导师】 苏永安； 徐重；

【作者基本信息】 太原理工大学 ， 材料加工工程， 2002， 硕士

【摘要】 纯铜具有高导电、导热性和一定的力学性能，使其成为工业上应用广泛的一种有色金属，但是纯铜又存在着强度低、硬度低、抗氧化性差等不足之处，使纯铜产品寿命短，不能满足某些工况条件下的需求。本文就是针对纯铜这些不足之处利用双层辉光离子渗金属技术在纯铜表面进行离子渗钛；同时为了和纯铜渗铝的抗高温氧化性能做对比，在纯铜表面进行了粉末渗铝。对纯铜表面双层辉光离子渗钛工艺过程、渗层的组织特征、渗层形成的机理等方面进行里详细的研究；对纯铜表面粉末渗铝的工艺，渗层组织特征，渗层形成的机理也进行了研究；对离子渗钛试样和纯铜、纯钛对比试样分别在0.5mol/LH₂SO₄、1mol/LH₂SO₄、1mol/LHCl、10％HNO₃和5％NaCl溶液中进行电化学腐蚀性能的研究；对离子渗钛试样和粉末渗铝试样以及纯铜试样在400℃和700℃高温循环氧化100小时的抗高温氧化性能进行了研究；对离子渗钛试样和纯铜试样在300N、500N和750N不同载荷下的摩擦磨损性能进行了研究；其中渗层的成分分布、显微特征、结构形貌采用了先进的XRD、SEM、BSE，EDS等手段进行了检测分析。 研究结果表明：利用双层辉光离子渗金属技术可以在纯铜表面形成厚度在20—90um之间变化，表面合金含量在30—90％（wt）之间变化的扩散层，是一种新型的梯度材料；用粉末法在纯铜表面也能形成含铝量不同的合金渗层。通过分析发现离子渗钛层中钛是以含钛的固溶体和铜钛金属间化合物Cu₄Ti等的形式存在，弥散分布的Cu₄Ti对铜基体起到强化作用，粉末渗铝的组织以α固溶体和共析体（α+γ₂）太原理工大学硕士论文组成。对离子渗钦试样和纯铜、纯钦对比试样分别在0.smo比HZSO4、lmol/LHZSo4、lmo比HCI、10%HNO3和so/6NaCI中进行电化学腐蚀性能研究，实验结果表明:离子渗钦层在0.smol/L HZSO;的腐蚀速度几乎与纯钦的相当，仅是纯铜的0.01倍;在lmol/L HZSO;是纯铜的0.1倍，是纯钦的3.2倍;在lmol/L HCI中离子渗钦层的腐蚀速度相对较大，但后期发生了钝化，而纯铜和纯钦发生了较为严重的孔蚀;在10%HNO3中离子渗钦层的腐蚀速度是纯铜的0.66倍，是纯钦的10倍;在5%NaCI中离子渗钦层的腐蚀速度是纯铜的2倍，但几乎与纯钦的相当:由于纯铜和纯钦均具有较好的耐蚀性，所以说明离子渗钦层在不同的介质中也均具有较高的耐蚀性。对离子渗钦试样和粉末渗铝试样以及纯铜试样在400℃和700OC高温循环氧化100小时的抗高温氧化性能进行了研究，分别给出了它们的氧化动力学曲线，并氧化机理进行了探讨，结果显示:纯铜离子渗钦后也可以大大提高纯铜的抗高温氧化性能，铜的氧化速率K。值在400‘C和700℃时均比离子渗钦和渗铝试样的几乎大一个数量级;在400℃时离子渗钦层生成的氧化膜致密，氧化速度慢，不容易剥落，比渗铝试样的抗氧化性能有绝对的优势;在700℃离子渗钦层在氧化80小时后才有剥落现象，而渗铝试样在氧化40小时就开始剥落，而且离子渗钦试样的速率常数K，值也比渗铝的小，说明在700℃离子渗钦试样的抗氧化性能要比渗铝的还要好。对离子渗钦试样和纯铜试样在300N、500N和75ON不同载荷下的摩擦磨损性能进行了研究，并对磨损机理进行了分析，结果显示:由于渗钦后表面硬度的提高大大降低了磨损次表面的塑性变形，阻止了磨损裂纹的形成与扩展，从而减小了磨损量，在300N纯铜试样的质量磨损量是离子渗钦试样的5倍多，在500N时约为11倍，在750N太原理工大学硕_1沦文时不考虑时间因素是17倍。更多还原

【Abstract】 Pure copper is extensively used as high electrical and thermal conductors. But pure copper is relatively soft and possesses a poor strength and hardness and high temperature oxidation resistance , which is not able to meet the need of industry. In order to improve the mechanical strength of copper, in this paper double glow discharge plasma titanizing surface alloying have been carried out on copper substrate. At the same time for contrast of high temperature oxidation resistance powder aluminizing was carried out. The processes of double glow discharge plasma titanizing , surface alloying layer micro-structure and diffusion mechanism were investigated in details also. The processes of powder aluminizing, surface alloying layer micro-structure and diffusion mechanism were also investigated in details. The corrosion resistance of plasma titanizing alloying layer has been investigated by electrochemical method in 0.5mol/LH2SO4, lmol/LH2SO4, Imol/LHCK 10%HNO3 and 5%NaCl solution respectively. The high temperature oxidation resistance of plasma titanizing alloying layer and aluminium alloying layer at 400℃ and 700℃ after oxidation 100 hours were investigated. The friction wear properties and wear mechanism of plasma titanizing alloying layer were studied. The compositions and microstructure of surface alloying layer wereinvestigated by the advanced means of XRD,SEM,BES,EDS.The experimental results show that copper surface can form titanium alloying layer with double glow discharge plasma surface alloying. The thickness of diffusion layer is between 20um and 90um and the surface titanium concentration is between 30% and 90%(wt). Aluminium diffusion layer is also able to form by use of powder aluminizing. In the plasma titanizing alloying layer titanium solute in copper and form the precipitation Cu4Ti. Copper is strengthened by the dispersion of Cu4Ti. The aluminium alloying layer is made of solid solution and precipitate. The corrosion resistance experiment indicated that corrosion rate of plasma titanizing alloying layer was equal to that of titanium,0.01 times that of copper in 0.5mol/LH2SO4 solution, and was 0.1 times that of copper and was 3.2 times of titanium in 0.5mol/LH2SO4 solution.The corrosion rate of plasma titanizing alloying layer was faster than that of copper and titanium in Imol/LHCl solution , but plasma titanizing alloying layer became of passivation at the later stage ,while copper and titanium surface occurred seriously aperture corrosion. The corrosion rate of plasma titanizing alloying layer is 0.66 times that of copper and 10 times that of titanium in 10%HNO3 solution. The corrosion rate of plasma titanizing alloying layer was almost equal to that of titanium and 2 times that of copper in5%NaCl solution. The oxidation kinetics curve is worked out and the oxidation resistance mechanism is studied. The results show that plasma titanizing on copper surface can improve greatly the high temperature oxidation resistance of copper. The oxidation rate of copper is almost 10 times that of plasma titanizing sample and powder aluminizing sample. At 400 ℃ theoxidation film of plasma titanizing sample is very dense and was not easily exfoliated. The oxidation resistance of plasma titanizing sample is much belter than of powder aluminizing sample. At 700℃ the oxidation film of plasma titanizing sample is exfoliated after oxidation 80 hours, but oxidation film of powder aluminizing sample is exfoliated after oxidation 40 hours. The oxidation rate of plasma titanizing sample is less than that of powder aluminizing sample. It is indicated the oxidation resistance of plasma titanizing sample is better than that of powder aluminizing sample. The friction wear properties and wear mechanism of plasma titanizing sample at 300N,500N and 750N are studied. The results show wear quantity of plasma titanizing sample is less .It is due to improve the surface hardness of plasma titanizing sample. The wear quantity of copper is 5 times that of plasma titanizing sample at 300N, 11 times at 500N, 17 ti更多还原