الفهرس 
EXPERIMENTAL PROCEDUREOnly 14 pages are availabe for public view
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Abstract
The present work is a study of the variation of
Young’s modulus of aluminium-base alloys in the AI-rich
corner of the AI-Cu-Ni ternary phase diagram. 58 different
alloys were prepared and tested. These alloys can be divid-
ed into wrought and cast alloys. The structure of these
alloys consisted of a solid solution matrix with different
combinations of dispersed phases, CuAI2(8), AI3Ni(E),
Cu4AI7Ni(T) and (CUNi)2AI3(O).
The Young’s modulus was measured using a dynamic
technique based on measuring the resonance frequency in
transverse vibrations of the specimen. An apparatus was
designed and constructed for this purpose. All measurements
were carried out at room temperature.
The results of this work showed that the dynamic
Young’s modulus is a structure-sensi tive property wh i ch is
affected by the size and morphology as well as the volume
fraction of the phases present in an alloy. Most of the
theoretical formulae used to predict Young’s modulus do not
take the structure into account which could lead to
inaccuracies.
A major mechanism which causes Young’s modulus to be
structure-sensitive is the constraint imposed on the
matrix by the dispersed phases. This constraint increases with the decrease in particle size and mean free path
between phases. This was considered to be the main reason
why the cast alloys have lower Young’s modulus than the
wrought alloys.