Article Periodicals » Materials Evaluation » Article
Micro Deformation Testing of Cast AM60B Mg Alloy Based on Scanning Electron Microscope and Digital Image Correlation Method

For the two phases of most cast magnesium alloys, cracks mainly occurred in the second phase, in which there were obvious black and white optical characterizations in scanning electron microscope (SEM) images. Quantitative evaluation of the effects of main phase deformation on cracking behavior was carried out based on SEM in-situ observation and the digital image correlation method (DICM). Crack initiation and previous propagation behaviors mainly depended on the plastic deformation of the αMg phase. There were sufficient plastic deformations, or displacement, of the main phase prior to the cracking in the boundary for most cast magnesium alloys. The effect of the applied direction on the micro deformation of all αMg grain boundaries was different. The rotational and inhomogeneous deformation fields in the local position were identified based on SEM in-situ observation and DICM.

References
Chasiotis, I. and W.G. Knauss, “A New Microtensile Tester for the Study of MEMS Materials with the Aid of Atomic Force Microscope,” Experimental Mechanics, Vol. 42, No. 1, 2002, pp. 51-57. Dahle, A.K., Y.C. Lee, M.D. Nave, P.L. Schaffer and D.H. St. John, “Development of the As-Cast Microstructure in Magnesium-Aluminum Alloys,” Journal of Light Metals, Vol. 1, 2001, pp. 61-72. Eberl, C., R. Thompson, D.S. Gianola, W.N. Sharpe and K.J. Hemker, Jr., “Digital Image Correlation and Tracking,” MATLAB File Exchange Server, 2006, www.mathworks.com. Gall, K., G. Biallas, H.J. Maier, P. Gullett, M.F. Horstemeyer, D.L. McDowell and J.H. Fan JH, “In-Situ Observations of High Cycle Fatigue Mechanisms in Cast AM60B Magnesium in Vacuum and Water Vapor Environments,” International Journal of Fatigue, Vol. 26, 2004, pp. 59-70. Hild, F., B. Raka, M. Baudequin, S. Roux and F. Cantelaube, “Multiscale Displacement Field Measurements of Compressed Mineral-Wool Samples by Digital Image Correlation,” Applied Optics, Vol. 41, No. 3, 2002, pp. 6815-6828. Kadiri, H.E., Y.B. Xue, M.F. Horstemeyer, J.B. Jordon and P.T. Wang, “Identification and Modeling of Fatigue Crack Growth Mechanisms in a Die-Cast AM50 Magnesium Alloy,” Acta Materialia, Vol. 54, 2006, pp. 5061-5076. Kleiner, S., O. Beffort, A. Wahlen and P.J. Uggowitzer PJ, “Microstructure and Mechanical Properties of Squeeze Cast and Semi-Solid Cast Mg-Al Alloys,” Journal of Light Metals, Vol. 2, 2002, pp. 277-280. Li, W.F. and X.P. Zhang, “Investigation of Initiation and Growth Behavior of Short Fatigue Emanating from a Single Edge Notch Specimen Using In- Situ SEM,” Materials Science and Engineering, Vol. 318, No. 1-2, 2001, pp. 129-136. Ma, S.P. and G.C. Jin, “Digital Speckle Correlation Method Improved by Genetic Algorithm,” Acta Mechanica Solida Sinca, Vol. 16, No. 4, 2003, pp. 366-373. Mordike, B.L. and T. Ebert, “Magnesium Properties: Applications – Potential,” Materials Science and Engineering, Vol. 302, No. 1, 2001, pp. 37-45. Peters, W.H. and W.F. Ranson, “Digital Imaging Techniques in Experimental Stress Analysis,” Optical Engineering, Vol. 21, No. 3, 1982, pp. 427- 431. Roux, M., F. Hild and Y. Berthaud, “Correlation Image Velocimetry: A Spectral Approach,” Applied Optics, Vol. 41, No. 1, 2002, pp. 108-115. Sonsino, C.M. and K. Dieterich, “Fatigue Design with Cast Magnesium Alloys Under Constant and Variable Amplitude Loading,” International Journal of Fatigue, Vol. 28, 2006, pp.183-193. Sutton, M.A., N. Li, D. Garcia, N. Cornille, J.J. Orteu, S.R. McNeill, H.W. Schreier and X.D. Li, “Metrology in a Scanning Electron Microscope: Theoretical Developments and Experimental Validation,” Measurement Science and Technology, Vol. 17, No. 10, 2006, pp. 2613-2622. Tang, B., S.S. Li, X.S. Wang, D.B. Zeng and R. Wu, “Effect of Ca/Sr Composite Addition into AZ91 Alloy on Hot-Crack Mechanism,” Scripta Materialia, Vol. 53, No. 9, 2005, pp. 1077-1082. Vendroux, G. and W.G. Knauss, “Submicron Deformation Field Measurement: Part 2. Improved Digital Image Correlation,” Experimental Mechanics, Vol. 38, No. 2, 1998, pp. 86-92. Wang, H., H. Xie, Y. Ju and Q. Duan, “Error Analysis of Digital Speckle Correlation Method Under Scanning Electron Microscope,” Experimental Techniques, Vol. 30, 2006, pp. 42-45. Wang, H.W., and Y.L. Kang, “Improved Digital Speckle Correlation Method and its Application in Fracture Analysis of Metallic Foil,” Optical Engineering, Vol. 41, No. 11, 2002, pp. 2793–2798. Wang, H.W., Y.L. Kang, Z.F. Zhang, et al., “Size Effect on Fracture Toughness of Thin Metallic Foil,” International Journal of Fracture, Vol. 123, No. 3-4, 2003, pp. 177-185. Wang, X.S. and J.H. Fan, “SEM Online Investigation of Fatigue Crack Initiation and Propagation in Notched Cast Magnesium Specimens,” Journal of Materials Science, Vol. 9, No. 7, 2004, pp. 2617-2620. Wang, X.S. and J.H. Fan, “An Evaluation on the Growth Rate of Small Fatigue Cracks in Cast AM50 Magnesium Alloy at Different Temperatures in a Vacuum Environment,” International Journal of Fatigue, Vol. 28, No. 1, 2006, pp. 79-86. Wang, X.S. and J.H. Fan, “Growth Rate of Small Fatigue Cracks of Cast Magnesium Alloy at Different Conditions,” Materials Science Forum, Vol. 546-549, 2007, pp. 77-80. Wang, X.S., F. Liang, J.H. Fan and F.H. Zhang, “Investigations on Low- Cycle Fatigue Small Crack Initiation and Propagation Mechanism of Cast Magnesium Alloys Based on SEM In-Situ Observation,” Philosophical Magazine, Vol. 86, No. 11, 2006, pp.1581-1596. Wang, X.S., X. Lu and H.D. Wang, “Investigation of Surface Fatigue Microcrack Growth Behavior of Cast Mg-Al Alloy,” Materials Science and Engineering, Vol. 364, 2004, pp. 11-16. Yamaguchi, I., “A Laser Speckle Strain Gage,” Journal of Physics, Vol. 14, No. 11, 1981, pp. 1270-1273.
Metrics
Usage Shares
Total Views
13 Page Views
Total Shares
0 Tweets
13
0 PDF Downloads
0
0 Facebook Shares
Total Usage
13