Numéro |
J. Phys. Colloques
Volume 48, Numéro C8, Décembre 1987
Fifth European Conference on Internal Friction and Ultrasonic Attenuation in Solids
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Page(s) | C8-559 - C8-565 | |
DOI | https://doi.org/10.1051/jphyscol:1987888 |
J. Phys. Colloques 48 (1987) C8-559-C8-565
DOI: 10.1051/jphyscol:1987888
INTERNAL FRICTION IN MANGANESE-COPPER AND MANGANESE-COPPER-ALUMINIUM ALLOYS
T.S. KÊ, L.T. WANG et H.C. YIInstitute of Solid State Physics, Academia Sinica, Hefei, China
Abstract
Internal friction and elastic modulus of Mn-Cu alloys
containing 60 and 70 wt % Mn and of Mn-Cu-Al alloys containing about 40 wt %
Cu, 1.92-3.59 wt % Al were measured with acoustic frequency in the temperature
range of -150 to 150°C. The martensitic transformation peak and the twin
boundary relaxation peak which did not appear before ageing were observed above
room temperature after a definite ageing time in the temperature range under
the spinodal curve within the miscibility gap. It is shown that the
transformation peak proper is originated from the stress-induced movement of
the interface boundaries between the parent phase and the transformation
product, and the internal friction background at the low-temperature side of
the transformation peak which exhibits a very strong amplitude effect and shows
a strong non-linear behaviour, is originated from the hysteretic movement of
the martensite-martensite interfaces. It has also been found that the addition
of aluminium enhances the strength but reduces the internal friction of the
specimen. A choice of suitable ageing time and temperature can give an optimum
compromise of high strength and high internal friction.