Study on the electrodeposition method for Ni-based composite layer coating SiC and Al2O3 particles

• Main Authors: Shih-hua Tseng, 曾士華
• Other Authors: Rong-Tsong Lee
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/26446305601851175619

碩士 === 國立中山大學 === 機械與機電工程學系研究所 === 98 === Abstract In the study, amounts of ceramic particles in coating layer deposited on the surface of cathode specimen are investigated under two kinds of ceramic particles of Al2O3 and SiC mixed in the Nickel sulfate bath during electroplating or electrophoretic depositing process. According to the IEP of the particles, Al2O3 particles which showed the positive charge in the nickel sulfate bath are deposited onto the work-piece of cathode during electrophoretic deposition (EPD)process. And the other hand, SiC particles which showed Neutral ( or zero ) charge in the same bath are deposited onto the work-piece of cathode during electrolytic deposition (ELD)process. Therefore, it is expect that the composite electro - deposition layers on the work-piece have large amount of particles and high strength are fabricated by using the method of ELD–EPD–ELD in sequence (ELEPIS). In the experiment conditions, the bath mixing the SiC particle with average diameter of 3 μm and the Al2O3 particle with average diameter of 1 μm respectively is stirred using the air pump and the magnetic stirrer, concentration of 20 g/L for each particle is seted. EPD is carried out under the apply voltage of 30 V, and ELD is carried out under the current density of 3 ASD. Results show that the amount of Al2O3 particle deposited in the composite coating layer is about 29.25 wt% during EPD, and the amount of SiC particle deposited in the composite coating layer is large and its distribution is uniform during ELD. Moreover, ELEPIS is carried out in the bath mixing 4 g/L of SiC particle and 8 g/L of Al2O3 particle to fabricate the composite coating layer. Result shows that the hardness of composite coating layer is 527 Hv, which is two times of that using traditional ELD method. This indicates that the strength and wear resistance of Ni-SiC- Al2O3 composite coating layer fabricated by ELEPIS method is excellent. Keywords : EPD、ELD、ELEPIS