Paper Title:

Investigation on Fracture Mechanism of A356 during Thixo-Forging

Periodical Solid State Phenomena (Volumes 116 - 117)
Main Theme Semi-Solid Processing of Alloys and Composites
Edited by C.G. Kang, S.K. Kim and S.Y. Lee
Pages 140-144
DOI 10.4028/www.scientific.net/SSP.116-117.140
Citation Kai Kun Wang et al., 2006, Solid State Phenomena, 116-117, 140
Online since October, 2006
Authors Kai Kun Wang, R. Kopp, Gerhard Hirt
Keywords A356 Aluminum Alloy, Fracture Mechanic, SEM Image, Thixoforging
Price US$ 28,-
Article Preview
View full size
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.