Molten metal supply device and aluminum titanate ceramic member having improved non-wettability

Abstract

An electromagnetic type molten metal supply device having superior accuracy in supplying molten metal. This device is comprised of a rotary vane that rotates in accordance with the movement of molten metal inside a molten metal transport conduit, and the amount of molten metal being transported can be measured by detecting the rotational frequency of the rotary vane.

Description

BACK GROUND OF THE INVENTION 1. Field of the Invention This invention relates to a molten metal supply device that transports / supplies molten metallic aluminum and molten metallic sodium, for example. In addition, this invention relates to a technology for conferring and retaining the non-wettability of a ceramic member that comes into contact with a molten metal such as a molten aluminum alloy. 2. Description of the Related Art For example, a linear induction electromagnetic pump that confers a thrust to a molten metal by means of the electromagnetic induction effect is used to transport molten metals such as molten metallic sodium in a fast breeder reactor or molten metallic aluminum in a casting facility. In a molten metal supply device, in particular a molten metal supply device in a casting facility, it is important to supply a predetermined amount of molten metal to the cavity used for casting, in order to achieve casting accuracy. A molten metal supply device having an ...

AI Technical Summary

Benefits of technology

The present inventors have developed a molten metal supply device that uses an electromagnetic pump and which has good supply accuracy.

According to this device, the amount of molten metal transported by magnetic induction inside the transport conduit can be measured based upon the rotational frequency of the rotary vane that is detected by the detector. In addition, the amount of molten metal transported can also be regulated based upon the rotational frequency of the rotary vane. Because of this, the amount of molten metal supplied can be accurately controlled. In this device, it is preferred that a means for detecting the amount of molten metal inside the transport conduit be provided in the transport conduit. According to this aspect of the invention, accuracy and precision in the detection and control of the amount of molten metal transported, that are caused by changes in the amount of molten metal inside the transport conduit, can be corrected.

According to this method, a highly precise cast metal object can be easily obtained.

In addition, another aspect of the present invention provides, a measuring device for a molten metal supply device that uses an electromagnetic pump having: a rotary vane that is provided in a molten metal transport conduit and which is rotated in accordance with the movement of molten metal; and a detector that detects the rotational frequency of the rotary vane. In this measuring device, it is further preferred that a means of detecting the amount of molten metal inside the transport conduit be provided in the transport conduit. According to this device, the amount of molten metal transported can be measured with a high degree of accuracy.

In addition, the present inventors have studied the decrease in the non-wettability of aluminum titanate ceramic with respect to molten aluminum alloy, and have learned that silica added to aluminum titanate ceramic is reduced by Al and Mg in the molten aluminum alloy, synthesizing Si particles on the surface of the aluminum titanate ceramic and the presence of these Si particles reduces the non-wettability. Furthermore, it was learned that due to the reduction of the silica, MgO and Al2O are produced on the surface of aluminum titanate ceramic, and moreover because of these compounds, MgAlO4 is produced on the surface of aluminum titanate ceramic.

In other words, the present inventors have discovered that a reduction in non-wettability can be controlled or avoided, and non-wettability can be conferred and retained, by avoiding the presence or generation of Si on the surface of aluminum titanate ceramic that come into contact with the molten aluminum alloy.

Problems solved by technology

However, since an electromagnetic pump confers a thrust to the molten metal, which is a fluid, it is difficult to accurately control the transfer volume thereof by means of current control.

Even when a discharge cylinder is provided for supplying a molten metal to the cavity, the molten metal supply accuracy of the electromagnetic pump ultimately becomes a problem.

However, aluminum titanate ceramic only appears to possess low thermal resistance because of cracks that appear at its grain boundaries.

Thus, the fact that the mechanical strength thereof is considerably weakened by these cracks at the grain boundaries is a problem.

As a result, it will be difficult to supply a predetermined quantity of molten metal to the forming machine, and this will cause an increase in the defect rate caused by changes in the weight of cast metal parts.

Furthermore, pieces of aluminum alloy that have been deposited and hardened on the spout of the ladle will come into contact with the casting system equipment, thus damaging the ladle itself or the ladling machine.

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