Abstract:

Orientation, hardness and Young's modulus of Al₃Sc single crystal were analyzed by using the electron back scatter diffraction (EBSD) and nanoindentation techniques. The results show that the Al₃Sc single crystal of about 1 mm in scale can be obtained by cooling eutectic Al-Sc alloy at rate of 60 ℃/h after heating to liquid. The hardness of the Al₃Sc single crystals orientated in (567), (139), (124), (113) and (144) directions is found to be between 3.7 and 4.3 GPa, and the composite elastic response modulus is between 143.6 and 146.1 GPa. By comparing the experimental and theoretical values of Young's modulus in each orientation under different Poisson's ratio, it can be concluded that the difference is the smallest when the Poisson's ratio is 0.188. The experimental Young's modulus in different orientations is between 157.5 and 160.6 GPa.

Key words: single crystal, nanoindentation, Young's modulus, anisotropy