Study of hot tear of AlCu5MgTi by restraining casting shrinkage in green-sand mold

The aim of this paper is to study hot tearing in aluminum alloy casting by impeding the solidification shrinkage in a sand mold. the instrumented constrained rod apparatus (icr) enables giving real-time measurements of the contraction load developed and temperature variations during solidification. two important parameters were extracted from plotted curves; dendrite coherency point (dcp) and rigidity temperature (tr). on the contrary,when the alloy was cast in the sand mold no cracks were observed because the casting is not hindered during solidification. with a fixed bolt,solidification shrinkage is upset and causes the hot tearing that is visually detected. thermal analysis and force developed curves allowed to elucidate crack initiation mechanism. the experiments clearly show that the rigidity temperature is a crucial parameter in hot tear initiation. © 2017,university of mohammed premier oujda morocco.