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CN-117358885-B - Slag-free pouring structure and method for single crystal or directional solidification casting

CN117358885BCN 117358885 BCN117358885 BCN 117358885BCN-117358885-B

Abstract

The invention discloses a slag-free pouring structure and a slag-free pouring method for a monocrystalline or directionally solidified casting, which aim to effectively prevent scum from flowing into a casting cavity and reduce impurities in the casting. Therefore, the slag-free pouring structure of the monocrystalline or directionally solidified castings provided by the invention comprises a directionally solidified furnace and a ceramic mould shell, wherein the ceramic mould shell is arranged on a lifting platform of the directionally solidified furnace, the directionally solidified furnace is provided with a hot chamber and a cold chamber, a pouring cup is arranged at the top of the ceramic mould shell, a tundish funnel is arranged right above the pouring cup at the top of the hot chamber, a plug is arranged in a funnel mouth of the tundish funnel, a top block aligned with the plug is arranged on the ceramic mould shell, the lifting platform drives the ceramic mould shell to lift the plug in the rising process of the hot chamber, and purified alloy liquid in the tundish funnel flows into the pouring cup through the funnel mouth.

Inventors

  • WEI JIANHUI
  • MA DEXIN
  • ZHAO YUNXING
  • WU GANG
  • GONG XIAOYI
  • LIN WEIGUANG

Assignees

  • 深圳市万泽中南研究院有限公司
  • 深圳市万泽航空科技有限责任公司

Dates

Publication Date
20260512
Application Date
20230912

Claims (6)

  1. 1. The slag-free pouring structure of the monocrystalline or directionally solidified casting comprises a directional solidification furnace and a ceramic mould shell (1), wherein the ceramic mould shell (1) is arranged on a lifting table (2) of the directional solidification furnace, the directional solidification furnace is provided with a hot chamber (3) and a cold chamber (4), and is characterized in that a pouring cup (5) is arranged at the top of the ceramic mould shell (1), a tundish funnel (6) is arranged right above the pouring cup (5) at the top of the hot chamber (3), a plug (7) is arranged in a funnel mouth of the tundish funnel (6), a top block (8) aligned with the plug (7) is arranged on the ceramic mould shell (1), and the lifting table (2) drives the ceramic mould shell (1) to lift up in the hot chamber (3), so that alloy liquid in the tundish funnel (6) can flow into the pouring cup (5) through the funnel mouth; When the lifting table (2) drives the ceramic mould shell (1) to move downwards in the hot chamber (3), the plug (7) can be automatically reset to plug the hopper mouth; A plug rod (9) which extends out of the hopper mouth and is matched with the top block (8) is formed below the plug (7), the plug (7) is in conical surface contact with the hopper mouth, and a liquid leakage gap is formed during separation; The top block (8) is fixedly arranged in the pouring cup (5); The plug (7) is a conical ceramic plug, and the top block (8) is a strip-shaped ceramic block.
  2. 2. The slag-free pouring structure of single crystals or directionally solidified castings according to claim 1, characterized in that the top of the hot chamber (3) is provided with a furnace cover (10) which can be opened and closed and can cover the tundish funnel (6).
  3. 3. The slag-free pouring structure of single crystal or directional solidification castings according to claim 1, wherein the ceramic mold shell (1) is integrally formed with the pouring cup (5).
  4. 4. A slag-free pouring structure for single crystal or directionally solidified castings according to any of the claims 1-3, characterized in that the ceramic mold shell (1) is provided with a pouring channel (11) and a casting cavity (12), and the pouring opening of the pouring cup (5) is communicated with the casting cavity (12) through the pouring channel (11).
  5. 5. The slag-free pouring structure of single crystal or directional solidification castings according to claim 4, wherein the pouring opening of the pouring cup (5) is directly aligned with a vertical middle column pipe (13) communicated with the ceramic formwork (1), a plurality of casting cavities (12) are uniformly distributed around the vertical middle column pipe (13), and each casting cavity (12) is communicated with the upper end side part of the vertical middle column pipe (13) through one pouring channel (11).
  6. 6. A method for slag-free pouring of a single crystal or a directionally solidified casting, employing the single crystal or the directionally solidified casting slag-free pouring structure according to any one of claims 1 to 5, characterized by comprising the steps of: The ceramic mould shell (1) is lifted into a first position of a hot chamber (3) by a lifting table (2) for preheating, and alloy materials are melted by a crucible; (2) Pouring the alloy liquid into a tundish funnel (6), standing for a set time, and floating the impurities; (3) The ceramic mould shell (1) is driven by the lifting table (2) to continuously ascend to the second position of the hot chamber (3), in the process, the ejector block (8) pushes the plug (7) to open the funnel mouth of the tundish funnel (6); (4) Alloy liquid flows into the ceramic mould shell (1) along the funnel mouth for filling, impurities floating on the alloy liquid flow down finally, float on the upper surface of the pouring cup (5) and do not enter the casting cavity (12); (5) Then the ceramic mould shell (1) is lowered from the hot chamber (3) to the cold chamber (4) to finish the directional solidification of the alloy liquid.

Description

Slag-free pouring structure and method for single crystal or directional solidification casting Technical Field The invention belongs to the technical field of investment casting, and particularly relates to a slag-free pouring structure and method for a single crystal or directional solidification casting. Background The existing manufacturing process flow of the single crystal or directional casting generally comprises the following steps of pressing a wax mould, combining the wax mould, preparing a mould shell and smelting and pouring to obtain the single crystal or directional casting, wherein in the smelting and pouring process of the alloy, pouring is realized through tilting a crucible, and scum floating on alloy liquid is poured into a mould shell casting cavity first. Because the filter screen is arranged, the liquid slag inclusion cannot be prevented, and therefore, the inclusion defect in the casting is unavoidable. Disclosure of Invention The invention mainly aims to provide a slag-free pouring structure and a slag-free pouring method for a monocrystalline or directionally solidified casting, which aim to effectively prevent scum from flowing into a casting cavity and reduce inclusion defects in the casting. Therefore, the slag-free pouring structure of the monocrystalline or directionally solidified castings provided by the invention comprises a directionally solidified furnace and a ceramic mould shell, wherein the ceramic mould shell is arranged on a lifting platform of the directionally solidified furnace, the directionally solidified furnace is provided with a hot chamber and a cold chamber, a pouring cup is arranged at the top of the ceramic mould shell, a tundish funnel is arranged right above the pouring cup at the top of the hot chamber, a plug is arranged in a funnel mouth of the tundish funnel, a top block aligned with the plug is arranged on the ceramic mould shell, and the top block can jack the plug when the lifting platform drives the ceramic mould shell to lift in the hot chamber, so that alloy liquid in the tundish funnel flows into the pouring cup through the funnel mouth. Specifically, a plug rod which extends out of the hopper mouth and is matched with the top block is formed below the plug, the plug at the upper part of the plug rod is in conical surface contact with the hopper mouth, and a liquid leakage gap is formed when the plug rod is separated from the hopper mouth. Specifically, the top block is fixedly arranged in the pouring cup. Specifically, when the lifting platform drives the ceramic mould shell to move downwards in the hot chamber, the blockage can be automatically reset to block the hopper mouth again. Specifically, the plug is a conical ceramic plug, and the top block is a strip-shaped ceramic block, so that the alloy liquid is not prevented from flowing down. Specifically, the ceramic mould shell is provided with a pouring channel and a casting cavity, and a pouring opening of the pouring cup is communicated with the casting cavity through the pouring channel. Specifically, the pouring opening of the pouring cup is directly aligned to and communicated with the vertical middle column pipe of the ceramic mould shell, a plurality of casting cavities are uniformly distributed around the vertical middle column pipe, and each casting cavity is communicated with the side part of the upper end of the vertical middle column pipe through one pouring channel. Specifically, the top of the hot chamber is provided with a furnace cover which can be opened and closed and can cover the tundish funnel. Specifically, the ceramic mould shell and the pouring cup are integrally formed. The invention also provides a slag-free pouring method of the monocrystalline or directional solidification casting, which adopts the slag-free pouring structure and comprises the following steps: (1) Lifting the ceramic mould shell into a first position of a hot chamber by using a lifting table for preheating, and melting alloy materials by using a crucible; (2) Pouring alloy liquid into a tundish funnel, and standing for a certain time to enable impurities to float to the surface of a molten pool; (3) The ceramic mould shell is driven by the lifting table to continuously lift to the second position of the hot chamber, in the process, the top block pushes up the plug, and the funnel mouth of the tundish funnel is opened; (4) Alloy liquid flows into the ceramic mould shell along the funnel mouth for filling, impurities floating on the surface of the molten pool finally flow down, float on the upper surface of the pouring cup liquid and do not enter the casting cavity; (5) Then the ceramic mould shell is lowered from the hot chamber to the cold chamber, and the metal liquid in the mould shell is directionally solidified. Compared with the prior art, at least one embodiment of the invention has the following beneficial effects: 1. the scum is prevented from flowing into the cavity, and the inclusion