AbstractEutectic structures of AgCu mixtures (71.90 wt% Ag) after melting and solidification in microgravity and on earth have been investigated by Barbieri and Patuelli. Results demonstrate morphological differences between rod-like and lamellar structures in specimens melted and solidified in μ-g and l-g. Spherical, rod-like and lamellar morphologies are also known in block copolymers, the molecules of which consist of lengths of two immiscible polymers attached to each other. We propose that in the absence of attachment between the components of the block copolymers, i.e. in blends (alloys) of the two polymers, the same morphological structures should be observed. In practice, in samples prepared on earth, the three characteristic morphologies are not observed. We suggest that phase separation in microgravity should lead to one or other characteristic morphology and that the observed morphology should correspond to a minimum surface area for the relative volume fractions of the two phases. We are therefore undertaking a series of experiments on polymeric and metallic mixtures to determine if the universality of the principle of minimization of interfacial area determines morphologies in systems not subject to interferences by factors involving gravitational effects.
Morphologies of metals and polymeric alloys in microgravity
Advances in Space Research ; 11 , 7 ; 323-326
1991-01-01
4 pages
Article (Journal)
Electronic Resource
English
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