High temperature compression behavior of the solid phase resulting from drained compression of a semi-solid 6061 alloy

Abstract

The aim of this work was to determine the high temperature compression behavior of the solid phase found in a semi-solid 6061 alloy by using an original procedure. A drained compressive test has been carried out to drain the majority of the liquid from the semi-solid alloy and obtain a solid representative of the solid phase of the alloy within the solidification range. The drained compressive tests have shown that the behavior of the semi-solid state is viscoplastic and depends on the initial morphology of the solid skeleton and on the accumulated strain. Then, compressive tests at high temperature have been carried out on drained and non-drained 6061 alloy. Results show that: (1) both alloys exhibit a behavior governed by a hyperbolic sine rheological law, (2) the deformation at high temperature of the drained alloy differs from the deformation of the non-drained 6061 alloy.

Modelling flow-induced microstructural segregation in semi-solid metals

“…The flow behaviour of SSMs is determined by the rheological behaviour of SSMs and casting parameters [18][19][20]. Thus far, studies have suggested that SSMs are pseudoplastic (shear thinning) with the most significant feature being the viscosity decrease with the increase in shear rate [21][22][23][24][25][26][27].…”

Time-dependent rheoforging of A6061 aluminum alloy on a mechanical servo press and the effects of forming conditions on homogeneity of rheoforged samples

“…The regions with a lower solid fraction exhibited lower yield strength and higher hardness. The higher hardness of liquid-phase regions resulted from the smaller particles of aluminum with a dendritic-structure, eutectic and intermetallic located in these regions [8]. The lower deformation resistance of the parts with a lower solid fraction was attributed to the defects in the liquid-phase regions, such as porosities and shrinkage.…”

Numerical Simulation of Liquid-Solid Extrusion Process Based on the Mechanical Model Coupled with Solidification

“…Qi et al [13] investigated the constitutive behavior of C /AZ91D composites compressed at elevated temperature and containing a small fraction of liquid. Giraud et al [14] investigated the high temperature compression behavior of a solid representative of the solid phase of the alloy within the solidification range by use of a drained compressive test, and the constitutive equation of the solid phase present in a semisolid 6061 alloy at a given temperature was determined. So the key to the success of simulation of deformation coupled with casting is the treatment to the deformation of the liquid zone.…”