Numéro
J. Phys. Colloques
Volume 48, Numéro C3, Septembre 1987
4th International Aluminium Lithium Conference
Page(s) C3-365 - C3-372
DOI https://doi.org/10.1051/jphyscol:1987342
4th International Aluminium Lithium Conference

J. Phys. Colloques 48 (1987) C3-365-C3-372

DOI: 10.1051/jphyscol:1987342

STUDIES ON EARLY AND LATE STAGES OF FORMATION OF δ' PHASES IN Al-Li ALLOYS BY NEUTRON SMALL ANGLE SCATTERING

S. FUJIKAWA1, M. FURUSAKA2, M. SAKAUCHI1 et K. HIRANO1

1  Tohoku University, Department of Materials Science, J-Sendai 980, Japan
2  Tohoku University, Physics Department, J-Sendai 980, Japan


Abstract
The phase separation process in Al-9.5 and 11.4 at.% Li alloys aged at 423 K has been studied over a wide q ( = ( 4πsinθ)/λ) range (0.06 < q <; 6 nm-1) witht the pulsed cold neutron small angle scattering instrument at National Laboratory for High Energy Physics. At very early stage, scattering function at the high q side is not only proportional to q-2, q-4 and q-6, but it obeys non-integer power of q. The power changes continuously from q-1.5 or q-2 to q-6 in very short time. At the laste stage, the scattering function consists of q-4 and q-5 dependences. The very interesting results can not be satisfactorily explained by the existing theories. The phase separation at the very early stage takes place by the spinodal mechanism, but some deviations are observed from the linear spinodal theory. At the late stage, the dynamic scaling law proposed by Furukawa and Lebowitz describes well the experimental results.