Physical Modeling of the Hydrodynamic Processes of Casting Molds Pouring Filled With a Locally Oriented Reinforcing Phase

Abstract

In the process of manufacturing reinforced castings by lost foam casting it is important to determine the laws of gas-hydrodynamic processes that occur during mold pouring. The study of liquid metal filling process a mold filled with a locally oriented reinforcing phase was carried out by the method of physical modeling using cold liquids on a special experimental bench that allows superimposing rarefaction to the front of the liquid metal. The video frames of the filling process the mold cavity without the reinforcing phase and with the presence of vertically mounted metal rods are obtained. It was established that the filling process without reinforcing elements occurs in three stages: 1) the flow of a gushing free stream into space; 2) the destruction of the free stream with the capture of the gas phase; 3) filling the form with a continuous stream with the removal of smaller gas inclusions from the liquid volume. It was also established that with an increase in the rarefaction, the character of filling the mold is preserved, only the intervals of existence of the corresponding stages are reduced. In the presence of a reinforcing phase in the cavity, a marked decrease in the height of the gushing of the jet in the initial stage with an increase in the number of installed rods. In addition, crushing by rods of a limited model space creates more favorable conditions for removing the filled gas phase from a moving stream.

Microstructure of Reinforced Cast Iron Produced by Lost Foam Casting

“…Depending on the amount of vacuum, the front of metal interaction with the pattern takes a different configuration [5], which can either contribute to the targeted removal of polystyrene degradation products through refractory coating or their delay on the reinforcement surface and the formation of defects in the casting. The presence in the pattern of reinforcing elements oriented along the direction of movement of the melt during the pouring of the alloy under vacuum creates conditions for leveling the metal front, which helps to remove the gases from the metal [17].…”