Effect of Surface Roughness on the Oxidation Behavior of a Directionally Solidified Ni-Based Superalloy at 1,100 °C

doi:10.1007/s40195-015-0211-2

Abstract

Abstract:

The effect of surface roughness on the oxidation behavior of a directionally solidified Ni-based superalloy was investigated by surface mapping microscope, scanning electron microscope and X-ray diffraction. It was found that specimens with surface roughness of 0.05 µm exhibit the best oxidation resistance, while specimens with surface roughness of 0.14 µm behave worse than specimens with surface roughness of 0.83 µm. The specimens with surface roughness of 0.05 µm have the best oxidation resistance, which is mainly due to the smallest surface area exposed in air and thinnest work-hardening layer. The Al₂O₃ layer alleviates the oxidation process of the specimens with surface roughness of 0.83 µm, and this is the possible reason for the better oxidation resistance of samples with surface roughness of 0.83 µm than samples with surface roughness of 0.14 µm.

Key words: Superalloy, Oxidation, Surface roughness, Surface area, Work hardening

Li Wang, Wei-Guo Jiang, Xiang-Wei Li, Jia-Sheng Dong, Wei Zheng, Hui Feng, Lang-Hong Lou. Effect of Surface Roughness on the Oxidation Behavior of a Directionally Solidified Ni-Based Superalloy at 1,100 °C[J]. Acta Metallurgica Sinica (English Letters), 2015, 28(3): 381-385.

Figures/Tables 8

Fig. 1 Schematic diagram of the cutting of oxidation samples Optical interferometry was performed by a surface mapping microscope (MicroXAM) to obtain 3D images to evaluate the surface roughness of samples with different finishes.

Fig. 2 Schematic illustration of the Knoop hardness test points on the sample surface

Fig. 3 Three-dimensional surface images and corresponding cross-sectional profiles of tested samples with surface roughness of a, b 0.83 µm, c, d 0.14 µm, e, f 0.05 µm

Fig. 4 Knoop hardness depth profiles of samples with different surface roughness

Fig. 5 Changes of mass gain versus exposure time during 1,100 °C oxidation of samples with different surface roughnesses

Fig. 6 XRD patterns of the samples with different surface roughnesses (Ra) after 30-min a, 300-min b exposure at 1,100 °C

Fig. 7 Surface morphologies of samples with surface roughnesses of 0.83 µm a, 0.14 µm b, 0.05 µm c after exposure in air at 1,100 °C for 300 min, and high magnification view of ABCD rectangle area in c, d

Fig. 8 The cross sections of specimens with surface roughnesses of a 0.83 µm, b 0.14 µm, c 0.05 µm after 1,100 °C, 300-min exposure in air

References 21

[1]	Z.Q. Hu, L.R. Liu, T. Jin, X.F. Sun, Aeroengine 31, 1 (2005)
[2]	A. Karabela, L.G. Zhao, B. Lin, J. Tong, M.C. Hardy, Mater. Sci. Eng. A 567, 46 (2013)
[3]	N. Czech, M. Juez-Lorenzo, V. Kolarik, W. Stamm,Surf. Coat. Technol. 108-109, 36(1998)
[4]	L. Huang, X.F. Sun, H.R. Guan, Z.Q. Hu,Surf. Technol. 200, 6863(2006)
[5]	K. Kawagishi, H. Harada, A. Sato, T. Kobayashi, J. Met. 58, 43(2006)
[6]	F.J. Liu, M.C. Zhang, J.X. Dong, Y.W. Zhang, Acta Metall. Sin. (Engl. Lett.) 20, 102(2007)
[7]	Q. Feng, B. Tryon, L.J. Carroll, T.M. Pollock, Mater. Sci. Eng. A 458, 184 (2007)
[8]	Y. Wu, T. Narita,Surf. Coat. Technol. 202, 140(2007)
[9]	C.T. Liu, J. Ma, X.F. Sun, J. Alloys Compd. 491, 522(2010)
[10]	A. Karabela, L.G. Zhao, J. Tong, N.J. Simms, J.R. Nicholls, M.C. Hardy, Mater. Sci. Eng. A 528, 6194 (2011)
[11]	Z.X. Shi, J.R. Li, S.Z. Liu, Trans. Nonferr. Met. Soc. China 22, 534 (2012)
[12]	A.M. Huntz, B. Lefevre, F. Cassino, Mater. Sci. Eng. A 290, 190 (2000)
[13]	Z.G. Zhang, P.Y. Hou, F. Gesmundo, Y. Niu,Appl. Surf. Sci. 253, 881(2006)
[14]	C. Ostwald, H.J. Grabke,Corros. Sci. 46, 1113(2004)
[15]	C. Liu, K.W. Li, J. Shen, J. Zhang, L.H. Lou, Metall. Mater. Trans. A 43A, 405 (2012)
[16]	N. Birks, G.H. Meier, F.S. Pettit, Introduction to the High-temperature Oxidation of Metals (Cambridge University Press, New York, 2006)
[17]	C.S. Giggins, B.H. Kear, F.S. Pettit, J.K. Tien, Metall. Mater. Trans. B 5, 1685 (1974)
[18]	Z.M. Li, S.Q. Qian, W. Wang,Appl. Surf. Sci. 257, 10414(2011)
[19]	L. Wang, X.G. Liu, J. Zhang, L.H. Lou,J. Iron Steel Res. 23, 353(2011)
[20]	J.A. Nychka, D.R. Clarke, G.H. Meier, Meier, Mater. Sci. Eng. A 490, 359 (2008)
[21]	J. Chao, J.L. Gonzalez-Carrasco, Meier, Mater. Sci. Eng. A 230, 39 (1997)