ISSN: 1003-6326
CN: 43-1239/TG

Vol. 24    No. 11    November 2014

Effect of pore structures on corrosion resistance of porous Ni3Al intermetallics
Liang WU1,2, Yue-hui HE2, Yao JIANG2, Yi ZENG2, Yi-feng XIAO1, Bo NAN2
(1. Key Laboratory of Materials Design and Preparation Technology of Hunan Province,
School of Mechanical Engineering, Xiangtan University, Xiangtan 411105, China;
2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China
Abstract: Porous Ni3Al intermetallics were fabricated by elemental powder reactive synthesis method, using carbamide powders as space holders. Corrosion behavior of porous Ni3Al intermetallics was investigated in a 6 mol/L KOH solution using electrochemical methods and immersion test. Effect of porous structures on the corrosion behavior of the porous Ni3Al intermetallics was studied. The results indicate that the porous Ni3Al intermetallics with higher porosities suffer more serious corrosion than the ones with lower porosities because the complicated interconnected porous structures and the large true surface areas exist in the samples with a higher porosity. But the corrosion rates of the porous Ni3Al intermetallics are not proportional to the true surface areas. The reason is that the pore size, pore size distribution and pore shape of the porous Ni3Al intermetallics change with the increasing porosity. All the porous Ni3Al intermetallics with different porosities exhibit excellent corrosion resistance in a strong alkali solution.
Key words: nickel aluminide intermetallic; corrosion; pore structure
Superintended by The China Association for Science and Technology (CAST)
Sponsored by The Nonferrous Metals Society of China (NFSOC)
Managed by Central South University (CSU)