A micromechanics study of lamellar TiAl

作者：Chang S^*; Chiang FP; Rosenberger AH

来源：Experimental Mechanics, 2006, 46(2): 173-178.

DOI：10.1007/s11340-006-5866-1

• computer aided speckle interferometry
• full-field strain mapping
• nondestructive evaluation
• scanning electron microscopy
• speckle interferometry with electron microscopy

Microdeformation patterns of lamellar TiAl specimens with various grain sizes under uniaxial tension are mapped using the micro/nano experimental mechanics technique called SIEM (Speckle Interferometry with Electron Microscopy). The stress-strain relationships were obtained from deformations within decreasing areas ranging from mm to mu m(2). We found that the stress-strain relationship of the material depends on the size of strain measuring area in relation to the grain size. The stiffness at a grain boundary can be as large as 7-10 times more than that of the grain itself. From the data obtained so far, it seems that the traditional way of using PST (polysynthetically twinned) single crystal to predict polycrystalline behavior may not be appropriate.

• 出版日期2006-4