Experimental Investigations on the Formation of Rosettes during Shear

In this work, the effect of stirring conditions on agglomeration and coalescence-coarsening in isothermal, globulitic, semisolid AlCu10%wt was investigated. It is shown that for the investigated system, a shear rate regime exists which promotes crystallographic alignment of the agglomerated grains, leading to a rapid coalescence process, thereby the formation of rosettes. It is also experimentally validated that for lower shear rates, the size and porosity of aggregates are increased compared to that at higher level of shear.