Nozzle for liquid beam electroforming square-section metal structure

Abstract

The invention discloses a nozzle for a liquid beam electroforming square-section metal structure. The nozzle is in an equal-wall-thickness hollow square tube shape with a rectangular cross section, and is provided with an upper flow guide section and a lower flow guide section; the periphery of the lower flow guide section is provided with micro-grid gaps and micro-grids; and the micro-grids comprise middle micro-grids located in the middle of each edge of the nozzle and corner micro-grids located at four corners. The width w1 of the micro-grid gaps is equal to the width w2 of the middle micro-grids. The thickness w3 of the corner micro-grids is equal to the wall thickness w5 of the nozzle, and the width w4 is equal to the sum of w5 and w2. The side edge of the lower end of each micro-grid is provided with a 45-degree chamfer. Due to the arrangement of the micro-grid gaps, the contact area between the electroforming liquid flow and the inner wall of the nozzle can be greatly reduced, so that the liquid flow bears smaller surface tension before entering a machining gap to form a liquid beam, and the liquid resistance is correspondingly reduced, so that the shrinkage deformation of the liquid beam can be slowed down, the square-section shape of the liquid beam can be continuously maintained, and a square-section metal structure can be electroformed. The invention aims to provide a nozzle with a high-precision square-section metal structure which is efficiently formed at one time in a liquid beam electroforming mode.

Description

technical field [0001] The invention relates to a nozzle used for liquid beam electroforming square-section metal structure, which belongs to the technical field of electrodeposition processing. Background technique [0002] Electroforming is a special processing technology based on the principle of electrochemical deposition to realize precision features and parts manufacturing. Jet electroforming is one of the most representative electroforming technologies. It has great development potential in the field of metal additive manufacturing due to its advantages of good localization and high degree of freedom of operation. Liquid beam electroforming (Wang Wei, Ming Pingmei et al. Research on Micro-liquid Column Confined Electrodeposition Processing Technology [A]. Proceedings of the 18th National Special Processing Academic Conference (Abstract) [C]. Special Processing of Chinese Mechanical Engineering Society Branch, 2019: 1.) is a special form of jet electroforming technolo...

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Problems solved by technology

[0003] At present, the nozzles used in liquid beam electroforming are generally circular nozzles. Although this type of nozzle can produce circular cross-section cylindrical metal parts with good structural symmetry, due to the effect of surface tension around the electroforming liquid beam, it The flow velocity of the formed liquid jet often presents an uneven distribution feature with a high center and a low periphery.

Moreover, if it is necessary to manufacture a metal product with a width much larger than the diameter of the circular nozzle, it must be realized by repeated shifting and scanning. Even so, the cross-sectional shape of the metal part is difficult to appear square features, and this shift scanning method inevitably leads to the occurrence of electroformed layer overlap or seam defects

In this regard, if the direct use of square mouth nozzles (especially large aspect ratio square mouth nozzles) should bring certain positive effects, however, it is extremely difficult for conventional square mouth nozzles to meet the ideal preparation requirements

This is because, if Figure 4 As shown, when the electroforming liquid flow with a relatively low flow rate leaves the square-mouth nozzle and enters the machining gap to form an electroforming liquid beam, the liquid beam is no longer restricted by the surface tension and shaping effect of the inner wall of the nozzle and is in a relatively free state. , at this time, due to the surface tension at the gas-liquid interface and the surface area minimization effect, the liquid beam gradually deforms after a small distance away from the square-mouth nozzle, and the original surface tension of the inner wall of the long side of the square-mouth nozzle is greater The acting liquid jet becomes shorter and rounder to reduce its surface area, and then becomes an elliptical cross-section liquid jet, and then further becomes a circular cross-section liquid jet. In this way, the square mouth nozzle finally loses its ability to form a square cross-section liquid jet Therefore, based on the conventional square mouth nozzle, the expected square cross-section metal structure cannot be electroformed by the liquid beam.

[0004] Although the flow rate of electroforming liquid is extremely high and the processing gap is smaller, the electroforming liquid beam leaving the square mouth nozzle can maintain a square cross-sectional feature for a long distance to the surface of the cathode substrate, but such a liquid beam impacts on the cathode substrate. Powerful, the distribution of the flow field is extremely uneven, and the reflection of the liquid flow is serious, it is not suitable as a tool carrier for electroforming, and it is impossible to electroform a high-quality square-section metal structure based on this

There is also a method of mask electroforming (such as the technical solution described in the patent application number CN201810822448.X) that first uses a high-cost photolithography process to prepare a square film structure, and then performs electrodeposition replication, but this method relies heavily on The photolithography film-making process with complex operation steps, and it is impossible to prepare three-dimensional complex shape parts with free spatial changes

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