Foam ceramic composite filtering method for high-temperature alloy in centrifugal field

Abstract

The invention discloses a foam ceramic composite filtering method for a high-temperature alloy in a centrifugal field. The method comprises the following steps: (1) prefabricating a special-shape refractory ceramic runner combining a sprue and an outlet channel vertical to the sprue, and placing multiple foam ceramic filtering sheets in the outlet channel of the runner; (2) superposing the axis of the sprue on the rotation axis of a centrifuge device; (3) before pouring, preheating the runner and the foam ceramic sheets to over 1000 DEG C; and (4) starting the centrifuge device to rotate the runner, wherein the rotation speed of the centrifuge device ranges from 10 r / min to 3,000 r / min; and pouring the high-temperature alloy melt which passes through the foam ceramic filtering sheets under the action of centrifugal force. The invention has the advantages that: the method is simple and convenient to operate; and after the high-temperature alloy is purified, the removal rate of oxides larger than 1 mu m can reach over 90%, and the purification requirements on the mother alloy or returns of the high-temperature alloy in the manufacturing of modern aircraft engines are completely met.

Description

technical field [0001] The invention relates to a composite filtration method of foam ceramics, in particular to a composite filtration method of foam ceramics in a superalloy centrifugal force field. Background technique [0002] With the continuous improvement of the performance of modern aero-engines, the requirements for the cleanliness of high-temperature alloy materials for aero-engines are also getting higher and higher. In the existing aero-engine manufacturing technology, foam ceramics are generally used to filter superalloy master alloys and return materials. It is a filter medium with a deep bed filtration mechanism. It relies on a large number of changeable small ceramic channels to capture the inclusion particles in the alloy melt through three mechanisms: mechanical barrier, surface adsorption and speed-down sedimentation, so that the alloy The melt reaches a higher degree of purification. The smaller the porosity of ceramic foam, the finer the ceramic channel...

AI Technical Summary

Problems solved by technology

However, the smaller the ceramic channel, the greater the thickness of the filter element, the greater the resistance to the flow of the alloy melt, and a higher flow pressure head is required to pass through. At the same time, the foamed ceramics with small pore size are easily blocked by larger inclusion particles. Not suitable for direct use

Since there are a variety of active alloying elements in the superalloy, in order to prevent the alloying elements from oxidizing and burning and forming inclusions, the superalloys used in aviation are all vacuum smelted. This smelting method limits the use of increasing the height of the liquid column and increasing the pressure head for the alloy melt. or the possibility of gas pressurization

In the existing high-temperature alloy foam ceramic filtration process, the minimum size of the foam ceramic pores does not exceed 20ppi, and the cleanliness of the master alloy and the returned material cannot meet the requirements of modern aero-engine manufacturing for the purification of high-temperature alloy melts

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