【作者】 穆高林；

【导师】 姚素薇；

【作者基本信息】 天津大学 ， 应用化学， 2007， 硕士

【摘要】 随着纳米科学的不断发展,复合镀技术迎来了新的契机。纳米粒子具有小尺寸效应、表面效应以及宏观量子隧道效应等,使其表现出独特的物理化学性能。将纳米粒子引入化学镀Ni-P合金镀液制备的Ni-P基纳米复合镀层,显示出优越的机械性能、电催化性能等,正日益成为科技工作者研究的重点。本论文通过向化学镀Ni-P合金镀液中加入纳米α-Al₂O₃粒子和纳米SiC粒子,利用化学沉积的方法,制备出Ni-P-纳米Al₂O₃复合镀层和Ni-P-纳米SiC复合镀层,考察了镀液中纳米粒子添加量、镀液温度、pH值等工艺参数对微粒复合量和镀速的影响。采用扫描电镜（SEM）和X射线衍射（XRD）对镀层表面形貌及结构进行了表征,同时研究了热处理前后镀层的耐磨性、显微硬度以及耐蚀性。实验结果表明:随着镀液中纳米微粒添加量的增大,镀层中纳米微粒的复合量先增大后减小,纳米Al₂O₃的复合量最高可达到10.1%（wt）,纳米SiC的复合量最高可达到13.1%（wt）。Ni-P-纳米Al₂O₃复合镀层和Ni-P-纳米SiC复合镀层的硬度、耐磨性以及耐蚀性均高于Ni-P合金镀层,而且随着纳米微粒复合量的增大,镀层硬度、耐磨性以及耐蚀性增大。当纳米Al₂O₃复合量为10.1%（wt）时,Ni-P-纳米Al₂O₃复合镀层的硬度达到627Hv,较Ni-P合金镀层增大28%,磨损失重减少20%以上。当纳米SiC复合量为13.1%（wt）时,Ni-P-纳米SiC复合镀层的硬度达到788Hv,较Ni-P合金镀层增大59%,磨损失重减少23%,在3.5% NaCl溶液中的耐蚀性也较Ni-P合金镀层有较大提高。400℃热处理后,复合镀层结构由非晶态转变为晶态,镀层硬度和耐磨性提高,但耐蚀性下降。更多还原

【Abstract】 With the development of nano science, the composite deposition receives a new opportunity. Nano particles have particular physical and chemical characterizations because of small dimension effect, surface effect, and macroscopical quanta tunnel effect etc. The Ni-P matrix nano composites that are obtained by incorporating nano particles into Ni-P bath show superior mechanism performance, electrical catalysis performance etc and are increasingly causing more and more attention of researchers.In this paper, nano-α-Al₂O₃ and nano-SiC powders were incorporated into Ni-P alloy matrix by electroless deposition to obtain nano Ni-P/Al₂O₃ and Ni-P/SiC composite coatings. The influence of concentration of particles in bath, temperature, pH and other technique parameters on nano particles content in coatings and rate of deposition was investigated. Scanning Electron Microscope （SEM） and X-ray diffraction （XRD） were used to figure the surface and microstructure of coatings. The wear resistance, micro-hardness and corrosion resistance of coatings before and after heat treatment were also studied. The results showed that with the increase of nano particle content in the electroless plating solution, the nano particle content in deposits increased first and then decreased, the nano-Al₂O₃ particle content in deposits can reached the maxium value in 10.1%（wt）, and the nano-SiC particle content in deposits can reached the maxium value in 13.1%（wt）. With the increase of nano particle content in deposits, the wear resistance, micro-hardness and corrosion resistance were developed and better than Ni-P alloy. Compared with Ni-P coatings, the hardness of Ni-P/nano-Al₂O₃ composite coating increased by 28%, while the wear loss decreased by over 20% when the nano-Al₂O₃ particle content in deposits reached 10wt.%, and the hardness of Ni-P/nano-SiC composite coating increased by 59%, while the wear loss decreased by over 23% when the nano-SiC particle content in deposits reached 13wt.%. Compared with Ni-P coatings, the corrosion resistance of Ni-P/nano-SiC composite was enhanced obviously. After 400℃heat treatment, the amorphous composite coating transforms to crystalline structure , the wear resistance and micro-hardness were increased, but corrosion resistance was decreased.更多还原