Prediction of rheological behaviour and segregation susceptibility of semi-solid aluminium–silicon alloys by a simple back extrusion test

Liquid segregation behavior of semi-solid AZ91 alloy during back extrusion test

“…The initial microstructure of the SSM billet has also been mentioned to play a role in liquid segregation [3,5]. This parameter is directly related to the production method of SSM billet [3,6]. Efforts have been dedicated to lower the manufacturing cost of SSM billet and provide an appropriate microstructure.…”

“…By choosing appropriate solid fractions and forming speeds during thixoforming, liquid segregation can be eliminated [2,4]. The initial microstructure of the SSM billet has also been mentioned to play a role in liquid segregation [3,5]. This parameter is directly related to the production method of SSM billet [3,6].…”

“…Kang and Jung [8] showed that in a series of Al alloys, by using adequate strain rate and solid fraction in compression test, liquid segregation can be avoided. Vieira and Ferrante [3] demonstrated that segregation behavior is strongly related to microstructure, obtained from different processes for SSM billet manufacturing. Yoshita et al [9] reported that the distribution of the solid globules in the matrix was improved with increasing of ram velocity in Al-4.5%Cu alloy during forging.…”

“…Liquid segregation is the major practical problem in semi-solid processes which leads to heterogeneous mechanical properties in a final product [2,3]. This phenomenon is a result of different flow behaviors of the solid globules with liquid phase; therefore a precise prediction of deformation behavior in semi-solid state is complicated.…”

Mechanical and Wear Properties of Friction Stir Welded 0–6Wt% nAl2O3 Reinforced Al-13Wt%Si Composites

“…The Welding Institute (TWI) UK [1] patented a solid-state joining method "friction stir welding" which has been used widely to produce high quality welds in many materials like aluminium, nickel, magnesium, titanium and steel for applications in automobiles Friction stir welding has an advantage over fusion welding of metal matrix composites owing to the absence of any kind of segregation and/or reaction to the reinforcements, hot cracking and porosity during the solid phase welding process. Al-Si alloy is one of the most popular materials for aerospace, automobile, and marine industries due to its high fluidity and castability, low density, high specific strength and good corrosion properties [13,14]. Silicon is known for reducing thermal expansion and increasing wear and corrosion resistance of the alloy [15].…”