In high pressure casting, most of pouring in pressure chamber is done by a robotic arm. During pouring process, impact of melt and pressure chamber is often accompanied by gas entering pressure chamber, which may cause defects in casting. Therefore, this article will discuss how to pour to avoid a large amount of gas entrainment.

General pouring method is to use a pouring spoon to directly pour melt into pressure chamber. This article proposes a new design to add a sleeve to pouring spoon and use a filter to pour (as shown in Figure 1), and compare entrained air content of the two.

 

Figure 1 A pouring spoon with a sleeve
This paper uses FLOW-3D CAST to simulate pouring in pressure chamber to observe distribution of entrained air during pouring process. Figure 2 shows pouring results of two different methods. From results, it can be seen that general pouring spoon will produce a large amount of entrained air due to impact during pouring, and there will also be large fluctuations in liquid surface. Pouring spoon with a sleeve is directly transferred into pressure chamber to avoid melt impact and entrained air. Table 1 shows results of entrained air volume using different cases. It can be found that general pouring spoon can avoid generation of entrained air by reducing pouring height.

 

(a) General pouring spoon

 

(b) Pouring spoon with sleeve
Figure 2 Analysis results of two pouring methods
Table 1 Entrained air volume under different cases

There is a filter screen in front of pouring spoon with sleeve, but because filter screen needs to be replaced, it will cause inconvenience during production. Therefore, this paper proposes another design to improve it (as shown in Figure 3). During production, roller will be used to drive filter screen to improve filtering effect of filter screen.

 

Figure 3 Pouring spoon with automatic filter screen replacement

It can be found through experimental verification that general pouring spoon has a large number of holes on the surface, and holes are reduced with filter screen. Pouring spoon with sleeve has almost no holes and fewer flow lines on the surface.

 

Figure 4 Experimental verification