Investigation on Fracture Mechanism of A356 during Thixo-Forging

Abstract:

Transmission electron microscopy (TEM) was used to assess the microstructural changes accompanying semisolid molding of a creep resistant Mg-5%Al-2%Sr alloy. It was revealed that the processing created thixotropic morphologies with globular solids of α-Mg, having well-developed sub-structures. The quickly-solidified liquid fraction, enriched in Al and Sr, led to the formation of increased volumes of a lamellae type Al4Sr phase, surrounding the secondary α-Mg. Traces of Mg17Al12 still existed, predominantly as irregular shape compounds located mainly in grain interiors. Both the primary solid and high melting point precipitates of Mn-Al modified with Sr, acted as nucleation substrates for secondary α-Mg grains.

• Periodical: Solid State Phenomena (Volumes 116-117)
• Pages: 140-144
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.116-117.140
• Online since: October 2006
• Authors: Kai Kun Wang, R. Kopp, Gerhard Hirt
• Keywords: A356 Aluminum Alloy, Fracture Mechanic, SEM Image, Thixoforging

References

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DOI: 10.1016/s1359-6454(01)00015-5