Microstructure—Property Relationship for Molded Alloys
The properties of alloys manufactured by semisolid forming are controlled by a unique microstructure that is essentially different from that obtained after processing using both conventional and novel technologies. Although the alloy phase composition is similar to that formed during die casting or rapid solidification, the phase morphology, and in particular the presence of primary solid particles, makes the difference in creating a kind of composite. A specific nature of the composite arises from the spherical particles imbedded in the matrix of solidified liquid fraction. As opposed to typical composites where the reinforcement particles have increased strength, in alloys processed in semisolid state, the primary particles of αMg are generally softer than the matrix. As a result, the mechanisms developed for conventional composites cannot be adopted here and a rule of mixtures does not explain the properties of molded alloys.
KeywordsMagnesium Alloy Solid Fraction Property Relationship Semisolid State AZ91D Magnesium Alloy
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