COATING THICKNESS ANALYSIS OF DEPOSITED FeCrAl SUBSTRATE BY γ-AL2O3 THROUGH NiO-ELECTROPLATING

Abstract

Nickel Oxide (NiO) have widely applied in industrial and automotive to forming oxide layer on the substrate due to it have high thermal stability and corrosion resistant. However, NiO was not directly diffused to the substrate via co-precipitation, spray-pyrolysis and sol-gel methods. Therefore, NiO-electroplating was performed in coating FeCrAl substrate by γ-Al2O3 powder. This method was conducted using various time of 15, 30, 45, 60 and 75 minutes, a current of DC power supply is 1.28A and sulphamate type solution. From the data shows that smallest surface roughness (Ra) of NiO-electroplating (EL) samples located at EL 30 min sample for 0.69 µm. Ra of raw material was lower than coated samples due to it performed by coating activity on the substrate. It supported by coating thickness analysis that treated samples has a higher coating thickness up to 11.3 µm. EDS analysis observed some elements on coated and uncoated samples such as Carbon (C) of 4.62-20.67%, Oxygen (O) of 6.16-19.62%, Nickel (Ni) of 6.76-25.14%, Iron (Fe) of 23.96-48.53%, Sodium (Na) of 2.21-9.95%, Chromium (Cr) of 7.97-15.59% and Aluminum (Al) of 2.17-3.12%. Those elements promote to develop a protective oxide layer on FeCrAl at a high temperature of 1000 0C.

New Method of Fabrication of Fe80Cr20 Alloy: Effect of its Technique on Crystallite Size and Thermal Stability

“…Crystallite size is decreased by mass gain which has decreased. It is relevant with the previous research that growth rate of crystallite size after consolidation process by using hot pressing was observed [3][4][5][6]9]. Growth rate was increased at the larger crystallite size.…”

“…Higher thermal stability shown by smaller mass gain during temperature operation. Other study of Fe80Cr20 alloy powder investigated that the effect of the various sintering process and Lanthanum (La) implantation on the crystallite size [5,6] and the results show that the growth rate of La implanted sample smaller than without La implanted during sintering process. Smaller crystallite size shows the smaller growth rate after sintering process.…”

“…Some previous research above shows that the crystallite size of Fe80Cr20 alloy, clear correlation with temperature operation. Ball milling and ultrasonic technique is shown inconvenience results in growth rate of crystallite size at high temperature operation [3][4][5][6][7][8][9][10][11]. Therefore, this study will combine between ball milling and ultrasonic technique.…”