Experimental verification of numerical predictions for the optimum plunger speed in the slow phase of a high-pressure die casting machine

Improving the quality of die castings through optimal plunger motion planning: analytical computation and experimental validation

“…Indeed, since acceleration measurements are usually not provided, the effect of acceleration is rarely accounted for in the literature, except for vibrocasting processes [24] or in some works focusing on [13,14].…”

“…Nonetheless, although no statistical correlation has been found between the static mechanical properties and the first stage speed v 1 (see [22]), the method here suggested can account also for constraints on v 1 that have already appeared in the literature. The first constraint is related to the existence of an upper bound on v 1 [12][13][14]. As demonstrated in the work of Zamora et al [13], if the plunger reaches a speed higher than a certain threshold value during the first stage, the wave of the molten metal will reflect against the chamber ceiling and its forward face might roll over, by causing air entrapment.…”

“…The first constraint is related to the existence of an upper bound on v 1 [12][13][14]. As demonstrated in the work of Zamora et al [13], if the plunger reaches a speed higher than a certain threshold value during the first stage, the wave of the molten metal will reflect against the chamber ceiling and its forward face might roll over, by causing air entrapment.…”

“…those adopted to define the plunger motion, since modifying the motion profile of the plunger is usually straightforward and costless. Some papers focus on the slow shot stage, by investigating the dynamic of the liquid metal flow as a function of the plunger speed and the possibility of air entrapment in the injection chamber of the die casting machine [12][13][14]. Indeed, the overall porosity in castings is considerably affected by the amount of air entrapped during the slow shot stage.…”

Equipo de fusión al vacío para la determinación cuantitativa del gas atrapado en piezas fundidas

“…Las dimensiones de la pieza, de 4 mm de espesor, y una fotografía del molde empleado se pueden ver en la figura 10. El proceso de inyección se efectúa del modo que se indica a continuación (una descripción detallada del sistema de inyección de esta máquina se puede encontrar en la literatura [23] ). Un pistón empuja desde la cámara de inyección horizontal al metal fundido para introducirlo en la cavidad del molde.…”