The influence of process parameters on micro electrodeposition Ni-Fe alloy column morphology, mechanical property and corrosion resistance

• Main Authors: Chun-chiang Huang, 黃俊強
• Other Authors: Jing-chie Lin
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/42525141283437932638

碩士 === 國立中央大學 === 機械工程研究所 === 98 === The effect of operational parameters (including voltage employed, composition of the bath and bath temperature in the micro anode guided electroplating) on the morphology, mechanical property and corrosion behavior of Ni-Fe alloy micro columns was of interest. The surface morphology was examined by scanning electron microscope. The mechanical property was tested by using a micro&nano-scale mechanical testing system to estimate the elastic modulus (Young’s modulus) and the corrosion behavior was evaluated by polarization resistance technique in 3.5 wt% NaCl solution. The results revealed that the micro columns have the smooth surface composed of tiny particles as the deposited from the bath with lower temperature (40℃) under lower voltage employed (4.0V). Their mechanical property was found to be better (with elastic modulus at 162.12GPa) than those (in the range from 106.32GPa to 23.62GPa) fabricated in a bath with higher temperature (i.e. in the range from 40 to 55℃) under higher voltage (in the range from 4.0V to 4.4V). In addition, the corrosion resistance for the micro columns deposited at lower temperature (40℃) and lower voltage (4.0V) is much better (with polarization resistance at 2.28×105Ω) than those (in the range from 1.82×105Ω to to 8.91×104Ω) obtained at higher temperatures (i.e. in the range from 40 to 50℃) and higher voltages (in the range from 4.0V to 4.4V). The variation of the morphology, mechanical property of the micro columns deposited depends upon the voltage, electrode separation and bath temperature those determined by distribution of electric field strength. The micro column appears in smooth surface consisting of tiny particles and dense internal structure. The columns with smooth surface and dense internal were arisen from a uniform, stable and weaker strength of electric field as the deposition taken place in a bath with lower temperature and lower voltage chosen in the electroplating. The micro columns with rough morphology containing, many imperfections in the crystal structure were ascribe to be electrodeposited under non-uniform, less stable and stronger strength of the electric field determined by the deposition conducted in a bath with higher temperature and higher voltages selected. According to the measurement of electroplating current density. When the current density is stable and uniform to maintain at 0.875±0.079mA (electrodeposition at 40℃ and 4.0V), Therefore, a micro columns with smooth morphology and dense internal (containing less imperfections) could be fabricated. Those micro columns revealed better mechanical property and corrosion resistance. Key words：Ni-Fe alloy, micro-anode guide electrodeposition, Young’s modulus