Ni-W基納米復(fù)合鍍層的制備及性能研究
發(fā)布時間：2018-07-14 22:32
【摘要】：性能優(yōu)異、制備工藝簡單的鎳-鎢(Ni-W)合金鍍層,常被用于機(jī)械、電子及軍工等領(lǐng)域。目前,將具有獨(dú)特性質(zhì)的納米顆粒摻雜入金屬基體所制備的納米復(fù)合鍍層材料日益受到重視。不同于直流電沉積,脈沖電沉積具有降低濃差極化、增加陰極活性極化的特點(diǎn)。因此利用多元材料復(fù)合的協(xié)同優(yōu)勢和脈沖電沉積的技術(shù)優(yōu)勢,能制備出具有優(yōu)異的耐腐蝕性能、機(jī)械性能、電催化性能的納米復(fù)合鍍層。本論文采用脈沖電沉積的方法,成功制備了鎳-鎢/多壁碳納米管(Ni-W/MWCNTs)、鎳-鎢/氮化硅(Ni-W/Si3N4)、鎳-鎢/氮化硼(Ni-W/BN(h))納米復(fù)合鍍層,系統(tǒng)地研究了鍍層的制備工藝及性能。對于Ni-W/MWCNTs納米復(fù)合鍍層,探討了電流密度、攪拌速度以及鍍液中MWCNTs的加量等工藝條件對MWCNTs復(fù)合量的影響,得到最佳制備工藝:MWCNTs 加量 3 g/L、電流密度 5 A/dm2、攪拌速度 200 rpm。Ni-W/MWCNTs 納米復(fù)合鍍層的顯微硬度隨著鍍層中納米粒子含量的增加而升高,而磨損率隨之降低。Ni-W/MWCNTs納米復(fù)合鍍層的摩擦系數(shù)明顯低于Ni-W合金鍍層。鍍層的耐腐蝕性能利用開路電位測試、電化學(xué)阻抗譜測試、極化曲線測試和腐蝕浸泡實(shí)驗(yàn)進(jìn)行分析。研究發(fā)現(xiàn),Ni-W/MWCNTs納米復(fù)合鍍層在中性、酸性及堿性的3.5wt%NaCl溶液中的抗腐蝕性均明顯優(yōu)于Ni-W合金鍍層。對于Ni-W/Si3N4納米復(fù)合鍍層,研究了脈沖頻率、占空比以及鍍液中Si3N4納米顆粒加量等因素對表面形貌、結(jié)構(gòu)以及Si3N4納米顆粒含量的影響。結(jié)果表明,最佳工藝條件為:Si3N4納米顆粒加量30 g/L、脈沖頻率1000 Hz、占空比60%。Ni-W/Si3N4納米復(fù)合鍍層的顯微硬度最高可達(dá)到Ni-W合金鍍層的兩倍。與Ni-W合金鍍層相比,Ni-W/Si3N4納米復(fù)合鍍層的自腐蝕電流密度更小,自腐蝕電位更高,耐腐蝕性能更好,同時表現(xiàn)出良好的耐摩擦磨損性能,磨損率隨著Si3N4納米顆粒加量的增加而呈現(xiàn)先減小后增大的趨勢。對于Ni-W/BN(h)納米復(fù)合鍍層,考察了脈沖頻率、鍍液溫度、鍍液中BN(h)納米粒子加量對顯微硬度、沉積速率以及表面形貌的影響。結(jié)果表明,最佳工藝條件為:BN(h)納米粒子加量5 g/L、脈沖頻率1000 Hz、鍍液溫度70℃。Ni-W/BN(h)納米復(fù)合鍍層的耐腐蝕性能高于Ni-W合金鍍層,且隨著鍍液中BN(h)納米粒子加量的增大而增大。Ni-W/BN(h)納米復(fù)合鍍層的磨損率和摩擦系數(shù)遠(yuǎn)遠(yuǎn)低于Ni-W合金鍍層。提高復(fù)合鍍層中BN(h)納米粒子的含量,鍍層的摩擦系數(shù)和磨損率隨之降低。
[Abstract]:Nickel-tungsten (Ni-W) alloy coatings with excellent properties and simple process are often used in mechanical, electronic and military industries. At present, nano-composite coating materials prepared by doping nano-particles into metal substrates have been paid more and more attention. Unlike DC electrodeposition, pulse electrodeposition has the characteristics of decreasing concentration polarization and increasing cathodic active polarization. Therefore, nanocomposite coatings with excellent corrosion resistance, mechanical properties and electrocatalytic properties can be prepared by using the synergistic advantages of multicomponent materials and the technical advantages of pulse electrodeposition. In this paper, Ni-W / MWCNTs, Ni-W / Si _ 3N _ 4 and Ni-W / W / BN (h) nanocomposite coatings were successfully prepared by pulse electrodeposition. For Ni-W / MWCNTs nanocomposite coating, the effects of current density, stirring speed and the amount of MWCNTs in bath on the composite amount of MWCNTs were discussed. The results show that the microhardness of the nano-composite coating increases with the increase of the content of nano-particles in the coating, the optimum preparation technology is 3 g / L, the current density is 5A / dm2and the stirring speed is 200rpm.Ni-W / MWCNTs nano-composite coating. The friction coefficient of Ni-W / MWCNTs nanocomposite coating is obviously lower than that of Ni-W alloy coating. The corrosion resistance of the coating was analyzed by open-circuit potential test, electrochemical impedance spectroscopy, polarization curve test and corrosion immersion test. It is found that the corrosion resistance of Ni-W / MWCNTs nanocomposite coating in neutral, acidic and alkaline 3.5 wtNaCl solution is obviously better than that of Ni-W alloy coating. For Ni-W / Si _ 3N _ 4 nanocomposite coating, the effects of pulse frequency, duty cycle and the amount of Si _ 3N _ 4 nanoparticles in the bath on the surface morphology, structure and content of Si _ 3N _ 4 nanoparticles were studied. The results show that the optimum conditions are as follows: 30 g / L, pulse frequency 1000 Hz, duty cycle ratio 60%. Ni-W / Si 3N 4 nanocomposite coating has the highest microhardness twice as high as Ni-W alloy coating. Compared with Ni-W alloy coating, Ni-W / Si _ 3N _ 4 nanocomposite coating has lower corrosion current density, higher corrosion potential, better corrosion resistance and better friction and wear resistance. The wear rate decreases first and then increases with the increase of the amount of Si _ 3N _ 4 nanoparticles. The effects of pulse frequency, bath temperature and amount of BN (h) nanoparticles on microhardness, deposition rate and surface morphology of Ni-W / BN (h) nanocomposite coatings were investigated. The results show that the optimum conditions are as follows: adding 5 g / L of (h) nanoparticles, pulse frequency 1000 Hz, bath temperature 70 鈩，
本文編號：2123168
[Abstract]:Nickel-tungsten (Ni-W) alloy coatings with excellent properties and simple process are often used in mechanical, electronic and military industries. At present, nano-composite coating materials prepared by doping nano-particles into metal substrates have been paid more and more attention. Unlike DC electrodeposition, pulse electrodeposition has the characteristics of decreasing concentration polarization and increasing cathodic active polarization. Therefore, nanocomposite coatings with excellent corrosion resistance, mechanical properties and electrocatalytic properties can be prepared by using the synergistic advantages of multicomponent materials and the technical advantages of pulse electrodeposition. In this paper, Ni-W / MWCNTs, Ni-W / Si _ 3N _ 4 and Ni-W / W / BN (h) nanocomposite coatings were successfully prepared by pulse electrodeposition. For Ni-W / MWCNTs nanocomposite coating, the effects of current density, stirring speed and the amount of MWCNTs in bath on the composite amount of MWCNTs were discussed. The results show that the microhardness of the nano-composite coating increases with the increase of the content of nano-particles in the coating, the optimum preparation technology is 3 g / L, the current density is 5A / dm2and the stirring speed is 200rpm.Ni-W / MWCNTs nano-composite coating. The friction coefficient of Ni-W / MWCNTs nanocomposite coating is obviously lower than that of Ni-W alloy coating. The corrosion resistance of the coating was analyzed by open-circuit potential test, electrochemical impedance spectroscopy, polarization curve test and corrosion immersion test. It is found that the corrosion resistance of Ni-W / MWCNTs nanocomposite coating in neutral, acidic and alkaline 3.5 wtNaCl solution is obviously better than that of Ni-W alloy coating. For Ni-W / Si _ 3N _ 4 nanocomposite coating, the effects of pulse frequency, duty cycle and the amount of Si _ 3N _ 4 nanoparticles in the bath on the surface morphology, structure and content of Si _ 3N _ 4 nanoparticles were studied. The results show that the optimum conditions are as follows: 30 g / L, pulse frequency 1000 Hz, duty cycle ratio 60%. Ni-W / Si 3N 4 nanocomposite coating has the highest microhardness twice as high as Ni-W alloy coating. Compared with Ni-W alloy coating, Ni-W / Si _ 3N _ 4 nanocomposite coating has lower corrosion current density, higher corrosion potential, better corrosion resistance and better friction and wear resistance. The wear rate decreases first and then increases with the increase of the amount of Si _ 3N _ 4 nanoparticles. The effects of pulse frequency, bath temperature and amount of BN (h) nanoparticles on microhardness, deposition rate and surface morphology of Ni-W / BN (h) nanocomposite coatings were investigated. The results show that the optimum conditions are as follows: adding 5 g / L of (h) nanoparticles, pulse frequency 1000 Hz, bath temperature 70 鈩，
本文編號：2123168
本文鏈接：http://sikaile.net/kejilunwen/huaxuehuagong/2123168.html
最近更新
教材專著
