Please use this identifier to cite or link to this item:
標題: 電解沉積氧化鋁陶瓷薄膜/無電鍍鎳在模具鋼SKD61之研究
The Study of Electrolytic Al2O3 Coating on Post Electroless Nickel Plating on SKD61 Mold Steel
作者: 何文賢
關鍵字: electrolytic Al2O3 coating;電解氧化鋁薄膜;electroless Nickel plating;SKD61 mold steel;無電鍍鎳;模具鋼
出版社: 材料工程學研究所
(1) 電解硝酸鋁溶液後所得氧化鋁粉之相變化過程為
(2) 電解沉積氧化鋁陶瓷薄膜之相變化過程為

The electrolytic deposition of alumina(Al2O3) coatings on post electrolytic Ni deposited SKD61 was conducted in an aqueous solution of alumina-nitrate[Al(NO3)3]. The better condition of alumina coatings on Ni alloy was determined by controlling different electrical-chemical parameter (solvent
、concentration、potential、time) and different sintering conditions. The followed characterizations were conducted by using Potentiostat、SEM/EDS、XRD、wear test and scratch test.
From the left shifting of the polarization curves, it was known that the diffusing of Al+3 ions in solvent is decreased with decreasing water content in electrolyte. A thicker alumina-film without cracks can be deposited in the electrolyte containing less water.
XRD diagrams indicate that the phase transformations of alumina are
(1) for alumina-powder
(2) for alumina-film
The above difference between alumina-powder and alumina-film is controlled by the water-contained amount of alumina-hydrate.
Through the cycle polarization test in 3.5%NaCl, it was found that the corrosion potential、corrosion current and protection potential of both Al2O3 deposited specimens are better than Ni alloy and substrate, except ta deposited specimen which showed a lower protection potential due to the cleavage of Al2O3 films after pitting.
The wear tests with a load of 24.5N show that the wear loss of alumina-films by Al alloy pin is lower than both that of Ni and SKD61. The least one is only 1/28 of SKD61 substrates.
SEM/EDS observations and the scratch tests, revealed that Ni layer was first detached from SKD61 under shear stress of 2.23GPa. This also means that the adhesion between Al2O3 and Ni is better than that between Ni and SKD61.
Appears in Collections:材料科學與工程學系

Show full item record

Google ScholarTM


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.